<p>As described in Paris et al. 2018, in that catalog you don't have the info for creating light curves.
If you go like here: <a href="http://skyserver.sdss.org/dr16/en/tools/chart/navi.aspx" rel="nofollow noreferrer">http://skyserver.sdss.org/dr16/en/tools/chart/navi.aspx</a>
you can get the spectra of objects selecting the coordinates. However, to get light curves I think you need the raw data.</p>

CC BY-SA 4.0
2021-10-10T07:13:35.497Z
I think this answers my question, thanks! As suggested by @ProfRob as well, I asked the question regarding how to obtain the Raw data in another [question](https://astronomy.stackexchange.com/q/47020/44051). That I am still unsure of!
mnuizhre
CC BY-SA 4.0
2021-10-10T00:24:57.323Z
2021-10-10T00:24:57.323Z
Alessandro Peca
<p>So, I am relatively comfortable with handling <span class="math-container">$\textit{FITS}$</span> files and hence I choose Python for the following operation.
The thing is that I need to analyse some Quasar light curves and hence I went to the DR14Q data release of the SDSS Survey <a href="https://www.sdss.org/dr14/algorithms/qso_catalog/" rel="nofollow noreferrer">here</a> in order to obtain the information on the <a href="https://data.sdss.org/sas/dr14/eboss/qso/DR14Q/DR14Q_v4_4.fits" rel="nofollow noreferrer">Quasar Files</a> (Big file don't open on data).</p>
<p>When I opened this files header on Python, I obtain:</p>
<pre><code>hdu_list = fits.open(file_pth)
hdu_list.info()
</code></pre>
<p>where file_pth is the fits file location.</p>
<p>I obtain the following output:</p>
<pre><code>Filename: /content/drive/MyDrive/RAD PRAC/SDSS.fits
No.    Name      Ver    Type      Cards   Dimensions   Format
  0  PRIMARY       1 PrimaryHDU      16   (7055,)   uint8   
  1  DR14Q_v4_4    1 BinTableHDU    328   526356R x 105C   [18A, D, D, J, I, J, I, 4A, D, D, 4A, D, D, D, I, D, D, D, K, K, K, K, K, K, I, I, I, 51J, 51J, 51J, 51A, D, D, I, A, I, I, A, 5D, 5D, 5D, 5D, D, 5D, D, D, D, D, D, D, D, D, D, D, D, E, D, D, D, D, D, D, E, I, D, D, E, I, D, D, E, I, D, D, D, D, D, D, D, D, D, D, D, D, D, D, D, D, D, 4A, 4A, D, E, D, D, D, D, D, D, D, D, I, D, D, D] 
</code></pre>
<p>Now, I try to open the file to see the whole array of data and I am confused out of these data given:</p>
<pre><code>XTENSION= 'BINTABLE'           / binary table extension                         
BITPIX  =                    8 / 8-bit bytes                                    
NAXIS   =                    2 / 2-dimensional table                            
NAXIS1  =                 1505 / width of table in bytes                        
NAXIS2  =               526356 / number of rows in table                        
PCOUNT  =                    0 / size of special data area                      
GCOUNT  =                    1 / one data group                                 
TFIELDS =                  105 / number of columns                              
EXTNAME = 'DR14Q_v4_4'         / table name                                     
TTYPE1  = 'SDSS_NAME'          / label for column 1                             
TFORM1  = '18A     '           / format for column 1                            
TUNIT1  = '-       '           / units for column 1                             
TTYPE2  = 'RA      '           / label for column 2                             
TFORM2  = 'D       '           / format for column 2                            
TUNIT2  = 'deg     '           / units for column 2                             
TTYPE3  = 'DEC     '           / label for column 3                             
TFORM3  = 'D       '           / format for column 3                            
TUNIT3  = 'deg     '           / units for column 3                             
TTYPE4  = 'THING_ID'           / label for column 4                             
TFORM4  = 'J       '           / format for column 4                            
TUNIT4  = '-       '           / units for column 4                             
TTYPE5  = 'PLATE   '           / label for column 5                             
TFORM5  = 'I       '           / format for column 5                            
TUNIT5  = '-       '           / units for column 5                             
TTYPE6  = 'MJD     '           / label for column 6                             
TFORM6  = 'J       '           / format for column 6                            
TUNIT6  = '-       '           / units for column 6                             
TTYPE7  = 'FIBERID '           / label for column 7                             
TFORM7  = 'I       '           / format for column 7                            
TUNIT7  = '-       '           / units for column 7                             
TTYPE8  = 'SPECTRO '           / label for column 8                             
TFORM8  = '4A      '           / format for column 8                            
TUNIT8  = '-       '           / units for column 8                             
TTYPE9  = 'Z       '           / label for column 9                             
TFORM9  = 'D       '           / format for column 9                            
TUNIT9  = '-       '           / units for column 9                             
TTYPE10 = 'Z_ERR   '           / label for column 10                            
TFORM10 = 'D       '           / format for column 10                           
TUNIT10 = '-       '           / units for column 10                            
TTYPE11 = 'SOURCE_Z'           / label for column 11                            
TFORM11 = '4A      '           / format for column 11                           
TUNIT11 = '-       '           / units for column 11                            
TTYPE12 = 'Z_VI    '           / label for column 12                            
TFORM12 = 'D       '           / format for column 12                           
TUNIT12 = '-       '           / units for column 12                            
TTYPE13 = 'Z_PIPE  '           / label for column 13                            
TFORM13 = 'D       '           / format for column 13                           
TUNIT13 = '-       '           / units for column 13                            
TTYPE14 = 'Z_PIPE_ERR'         / label for column 14                            
TFORM14 = 'D       '           / format for column 14                           
TUNIT14 = '-       '           / units for column 14                            
TTYPE15 = 'ZWARNING'           / label for column 15                            
TFORM15 = 'I       '           / format for column 15                           
TUNIT15 = '-       '           / units for column 15                            
TTYPE16 = 'Z_PCA   '           / label for column 16                            
TFORM16 = 'D       '           / format for column 16                           
TUNIT16 = '-       '           / units for column 16                            
TTYPE17 = 'Z_PCA_ER'           / label for column 17                            
TFORM17 = 'D       '           / format for column 17                           
TUNIT17 = '-       '           / units for column 17                            
TTYPE18 = 'Z_MGII  '           / label for column 18                            
TFORM18 = 'D       '           / format for column 18                           
TUNIT18 = '-       '           / units for column 18                            
TTYPE19 = 'BOSS_TARGET1'       / label for column 19                            
TFORM19 = 'K       '           / format for column 19                           
TUNIT19 = '-       '           / units for column 19                            
TTYPE20 = 'ANCILLARY_TARGET1'  / label for column 20                            
TFORM20 = 'K       '           / format for column 20                           
TUNIT20 = '-       '           / units for column 20                            
TTYPE21 = 'ANCILLARY_TARGET2'  / label for column 21                            
TFORM21 = 'K       '           / format for column 21                           
TUNIT21 = '-       '           / units for column 21                            
TTYPE22 = 'EBOSS_TARGET0'      / label for column 22                            
TFORM22 = 'K       '           / format for column 22                           
TUNIT22 = '-       '           / units for column 22                            
TTYPE23 = 'EBOSS_TARGET1'      / label for column 23                            
TFORM23 = 'K       '           / format for column 23                           
TUNIT23 = '-       '           / units for column 23                            
TTYPE24 = 'EBOSS_TARGET2'      / label for column 24                            
TFORM24 = 'K       '           / format for column 24                           
TUNIT24 = '-       '           / units for column 24                            
TTYPE25 = 'N_SPEC_SDSS'        / label for column 25                            
TFORM25 = 'I       '           / format for column 25                           
TUNIT25 = '-       '           / units for column 25                            
TTYPE26 = 'N_SPEC_BOSS'        / label for column 26                            
TFORM26 = 'I       '           / format for column 26                           
TUNIT26 = '-       '           / units for column 26                            
TTYPE27 = 'N_SPEC  '           / label for column 27                            
TFORM27 = 'I       '           / format for column 27                           
TUNIT27 = '-       '           / units for column 27                            
TTYPE28 = 'PLATE_DUPLICATE'    / label for column 28                            
TFORM28 = '51J     '           / format for column 28                           
TUNIT28 = '-       '           / units for column 28                            
TTYPE29 = 'MJD_DUPLICATE'      / label for column 29                            
TFORM29 = '51J     '           / format for column 29                           
TUNIT29 = '-       '           / units for column 29                            
TTYPE30 = 'FIBERID_DUPLICATE'  / label for column 30                            
TFORM30 = '51J     '           / format for column 30                           
TUNIT30 = '-       '           / units for column 30                            
TTYPE31 = 'SPECTRO_DUPLICATE'  / label for column 31                            
TFORM31 = '51A     '           / format for column 31                           
TUNIT31 = '-       '           / units for column 31                            
TDIM31  = '(1,51)  '           / dimensions for column 31                       
TTYPE32 = 'BI_CIV  '           / label for column 32                            
TFORM32 = 'D       '           / format for column 32                           
TUNIT32 = 'km/s    '           / units for column 32                            
TTYPE33 = 'ERR_BI_CIV'         / label for column 33                            
TFORM33 = 'D       '           / format for column 33                           
TUNIT33 = 'km/s    '           / units for column 33                            
TTYPE34 = 'RUN_NUMBER'         / label for column 34                            
TFORM34 = 'I       '           / format for column 34                           
TUNIT34 = '-       '           / units for column 34                            
TTYPE35 = 'RERUN_NUMBER'       / label for column 35                            
TFORM35 = 'A       '           / format for column 35                           
TUNIT35 = '-       '           / units for column 35                            
TTYPE36 = 'COL_NUMBER'         / label for column 36                            
TFORM36 = 'I       '           / format for column 36                           
TUNIT36 = '-       '           / units for column 36                            
TTYPE37 = 'FIELD_NUMBER'       / label for column 37                            
TFORM37 = 'I       '           / format for column 37                           
TUNIT37 = '-       '           / units for column 37                            
TTYPE38 = 'OBJ_ID  '           / label for column 38                            
TFORM38 = 'A       '           / format for column 38                           
TUNIT38 = '-       '           / units for column 38                            
TTYPE39 = 'PSFFLUX '           / label for column 39                            
TFORM39 = '5D      '           / format for column 39                           
TUNIT39 = 'nanomaggies'        / units for column 39                            
TTYPE40 = 'IVAR_PSFFLUX'       / label for column 40                            
TFORM40 = '5D      '           / format for column 40                           
TUNIT40 = '-       '           / units for column 40                            
TTYPE41 = 'PSFMAG  '           / label for column 41                            
TFORM41 = '5D      '           / format for column 41                           
TUNIT41 = 'mag     '           / units for column 41                            
TTYPE42 = 'ERR_PSFMAG'         / label for column 42                            
TFORM42 = '5D      '           / format for column 42                           
TUNIT42 = 'mag     '           / units for column 42                            
TTYPE43 = 'MI      '           / label for column 43                            
TFORM43 = 'D       '           / format for column 43                           
TUNIT43 = '-       '           / units for column 43                            
TTYPE44 = 'GAL_EXT '           / label for column 44                            
TFORM44 = '5D      '           / format for column 44                           
TUNIT44 = 'mag     '           / units for column 44                            
TTYPE45 = 'RASS_COUNTS'        / label for column 45                            
TFORM45 = 'D       '           / format for column 45                           
TUNIT45 = 'counts/s'           / units for column 45                            
TTYPE46 = 'RASS_COUNTS_SNR'    / label for column 46                            
TFORM46 = 'D       '           / format for column 46                           
TUNIT46 = '-       '           / units for column 46                            
TTYPE47 = 'SDSS2ROSAT_SEP'     / label for column 47                            
TFORM47 = 'D       '           / format for column 47                           
TUNIT47 = 'arcsec  '           / units for column 47                            
TTYPE48 = 'FLUX_0.2_2.0keV'    / label for column 48                            
TFORM48 = 'D       '           / format for column 48                           
TUNIT48 = 'erg/s/cm2'          / units for column 48                            
TTYPE49 = 'FLUX_0.2_2.0keV_ERR' / label for column 49                           
TFORM49 = 'D       '           / format for column 49                           
TUNIT49 = 'erg/s/cm2'          / units for column 49                            
TTYPE50 = 'FLUX_2.0_12.0keV'   / label for column 50                            
TFORM50 = 'D       '           / format for column 50                           
TUNIT50 = 'erg/s/cm2'          / units for column 50                            
TTYPE51 = 'FLUX_2.0_12.0keV_ERR' / label for column 51                          
TFORM51 = 'D       '           / format for column 51                           
TUNIT51 = 'erg/s/cm2'          / units for column 51                            
TTYPE52 = 'FLUX_0.2_12.0keV'   / label for column 52                            
TFORM52 = 'D       '           / format for column 52                           
TUNIT52 = 'erg/s/cm2'          / units for column 52                            
TTYPE53 = 'FLUX_0.2_12.0keV_ERR' / label for column 53                          
TFORM53 = 'D       '           / format for column 53                           
TUNIT53 = 'erg/s/cm2'          / units for column 53                            
TTYPE54 = 'LUM_0.2_12.0keV'    / label for column 54                            
TFORM54 = 'D       '           / format for column 54                           
TUNIT54 = 'erg/s   '           / units for column 54                            
TTYPE55 = 'SDSS2XMM_SEP'       / label for column 55                            
TFORM55 = 'D       '           / format for column 55                           
TUNIT55 = 'arcsec  '           / units for column 55                            
TTYPE56 = 'GALEX_MATCHED'      / label for column 56                            
TFORM56 = 'E       '           / format for column 56                           
TUNIT56 = '-       '           / units for column 56                            
TTYPE57 = 'FUV     '           / label for column 57                            
TFORM57 = 'D       '           / format for column 57                           
TUNIT57 = '-       '           / units for column 57                            
TTYPE58 = 'FUV_IVAR'           / label for column 58                            
TFORM58 = 'D       '           / format for column 58                           
TUNIT58 = '-       '           / units for column 58                            
TTYPE59 = 'NUV     '           / label for column 59                            
TFORM59 = 'D       '           / format for column 59                           
TUNIT59 = '-       '           / units for column 59                            
TTYPE60 = 'NUV_IVAR'           / label for column 60                            
TFORM60 = 'D       '           / format for column 60                           
TUNIT60 = '-       '           / units for column 60                            
TTYPE61 = 'JMAG    '           / label for column 61                            
TFORM61 = 'D       '           / format for column 61                           
TUNIT61 = 'Vega    '           / units for column 61                            
TTYPE62 = 'ERR_JMAG'           / label for column 62                            
TFORM62 = 'D       '           / format for column 62                           
TUNIT62 = 'Vega    '           / units for column 62                            
TTYPE63 = 'JSNR    '           / label for column 63                            
TFORM63 = 'E       '           / format for column 63                           
TUNIT63 = '-       '           / units for column 63                            
TTYPE64 = 'JRDFLAG '           / label for column 64                            
TFORM64 = 'I       '           / format for column 64                           
TUNIT64 = '-       '           / units for column 64                            
TTYPE65 = 'HMAG    '           / label for column 65                            
TFORM65 = 'D       '           / format for column 65                           
TUNIT65 = 'Vega    '           / units for column 65                            
TTYPE66 = 'ERR_HMAG'           / label for column 66                            
TFORM66 = 'D       '           / format for column 66                           
TUNIT66 = 'Vega    '           / units for column 66                            
TTYPE67 = 'HSNR    '           / label for column 67                            
TFORM67 = 'E       '           / format for column 67                           
TUNIT67 = '-       '           / units for column 67                            
TTYPE68 = 'HRDFLAG '           / label for column 68                            
TFORM68 = 'I       '           / format for column 68                           
TUNIT68 = '-       '           / units for column 68                            
TTYPE69 = 'KMAG    '           / label for column 69                            
TFORM69 = 'D       '           / format for column 69                           
TUNIT69 = 'Vega    '           / units for column 69                            
TTYPE70 = 'ERR_KMAG'           / label for column 70                            
TFORM70 = 'D       '           / format for column 70                           
TUNIT70 = 'Vega    '           / units for column 70                            
TTYPE71 = 'KSNR    '           / label for column 71                            
TFORM71 = 'E       '           / format for column 71                           
TUNIT71 = '-       '           / units for column 71                            
TTYPE72 = 'KRDFLAG '           / label for column 72                            
TFORM72 = 'I       '           / format for column 72                           
TUNIT72 = '-       '           / units for column 72                            
TTYPE73 = 'SDSS2MASS_SEP'      / label for column 73                            
TFORM73 = 'D       '           / format for column 73                           
TUNIT73 = 'arcsec  '           / units for column 73                            
TTYPE74 = 'W1MAG   '           / label for column 74                            
TFORM74 = 'D       '           / format for column 74                           
TUNIT74 = '-       '           / units for column 74                            
TTYPE75 = 'ERR_W1MAG'          / label for column 75                            
TFORM75 = 'D       '           / format for column 75                           
TUNIT75 = '-       '           / units for column 75                            
TTYPE76 = 'W1SNR   '           / label for column 76                            
TFORM76 = 'D       '           / format for column 76                           
TUNIT76 = '-       '           / units for column 76                            
TTYPE77 = 'W1CHI2  '           / label for column 77                            
TFORM77 = 'D       '           / format for column 77                           
TUNIT77 = '-       '           / units for column 77                            
TTYPE78 = 'W2MAG   '           / label for column 78                            
TFORM78 = 'D       '           / format for column 78                           
TUNIT78 = '-       '           / units for column 78                            
TTYPE79 = 'ERR_W2MAG'          / label for column 79                            
TFORM79 = 'D       '           / format for column 79                           
TUNIT79 = '-       '           / units for column 79                            
TTYPE80 = 'W2SNR   '           / label for column 80                            
TFORM80 = 'D       '           / format for column 80                           
TUNIT80 = '-       '           / units for column 80                            
TTYPE81 = 'W2CHI2  '           / label for column 81                            
TFORM81 = 'D       '           / format for column 81                           
TUNIT81 = '-       '           / units for column 81                            
TTYPE82 = 'W3MAG   '           / label for column 82                            
TFORM82 = 'D       '           / format for column 82                           
TUNIT82 = '-       '           / units for column 82                            
TTYPE83 = 'ERR_W3MAG'          / label for column 83                            
TFORM83 = 'D       '           / format for column 83                           
TUNIT83 = '-       '           / units for column 83                            
TTYPE84 = 'W3SNR   '           / label for column 84                            
TFORM84 = 'D       '           / format for column 84                           
TUNIT84 = '-       '           / units for column 84                            
TTYPE85 = 'W3CHI2  '           / label for column 85                            
TFORM85 = 'D       '           / format for column 85                           
TUNIT85 = '-       '           / units for column 85                            
TTYPE86 = 'W4MAG   '           / label for column 86                            
TFORM86 = 'D       '           / format for column 86                           
TUNIT86 = '-       '           / units for column 86                            
TTYPE87 = 'ERR_W4MAG'          / label for column 87                            
TFORM87 = 'D       '           / format for column 87                           
TUNIT87 = '-       '           / units for column 87                            
TTYPE88 = 'W4SNR   '           / label for column 88                            
TFORM88 = 'D       '           / format for column 88                           
TUNIT88 = '-       '           / units for column 88                            
TTYPE89 = 'W4CHI2  '           / label for column 89                            
TFORM89 = 'D       '           / format for column 89                           
TUNIT89 = '-       '           / units for column 89                            
TTYPE90 = 'CC_FLAGS'           / label for column 90                            
TFORM90 = '4A      '           / format for column 90                           
TUNIT90 = '-       '           / units for column 90                            
TTYPE91 = 'PH_FLAGS'           / label for column 91                            
TFORM91 = '4A      '           / format for column 91                           
TUNIT91 = '-       '           / units for column 91                            
TTYPE92 = 'SDSS2WISE_SEP'      / label for column 92                            
TFORM92 = 'D       '           / format for column 92                           
TUNIT92 = 'arcsec  '           / units for column 92                            
TTYPE93 = 'UKIDSS_MATCHED'     / label for column 93                            
TFORM93 = 'E       '           / format for column 93                           
TUNIT93 = '-       '           / units for column 93                            
TTYPE94 = 'YFLUX   '           / label for column 94                            
TFORM94 = 'D       '           / format for column 94                           
TUNIT94 = 'W/m2/Hz '           / units for column 94                            
TTYPE95 = 'YFLUX_ERR'          / label for column 95                            
TFORM95 = 'D       '           / format for column 95                           
TUNIT95 = 'W/m2/Hz '           / units for column 95                            
TTYPE96 = 'JFLUX   '           / label for column 96                            
TFORM96 = 'D       '           / format for column 96                           
TUNIT96 = 'W/m2/Hz '           / units for column 96                            
TTYPE97 = 'JFLUX_ERR'          / label for column 97                            
TFORM97 = 'D       '           / format for column 97                           
TUNIT97 = 'W/m2/Hz '           / units for column 97                            
TTYPE98 = 'HFLUX   '           / label for column 98                            
TFORM98 = 'D       '           / format for column 98                           
TUNIT98 = 'W/m2/Hz '           / units for column 98                            
TTYPE99 = 'HFLUX_ERR'          / label for column 99                            
TFORM99 = 'D       '           / format for column 99                           
TUNIT99 = 'W/m2/Hz '           / units for column 99                            
TTYPE100= 'KFLUX   '           / label for column 100                           
TFORM100= 'D       '           / format for column 100                          
TUNIT100= 'W/m2/Hz '           / units for column 100                           
TTYPE101= 'KFLUX_ERR'          / label for column 101                           
TFORM101= 'D       '           / format for column 101                          
TUNIT101= 'W/m2/Hz '           / units for column 101                           
TTYPE102= 'FIRST_MATCHED'      / label for column 102                           
TFORM102= 'I       '           / format for column 102                          
TUNIT102= '-       '           / units for column 102                           
TTYPE103= 'FIRST_FLUX'         / label for column 103                           
TFORM103= 'D       '           / format for column 103                          
TUNIT103= 'mJy     '           / units for column 103                           
TTYPE104= 'FIRST_SNR'          / label for column 104                           
TFORM104= 'D       '           / format for column 104                          
TUNIT104= '-       '           / units for column 104                           
TTYPE105= 'SDSS2FIRST_SEP'     / label for column 105                           
TFORM105= 'D       '           / format for column 105                          
TUNIT105= 'arcsec  '           / units for column 105                           
DATE-HDU= '2017-12-08T23:27:28' / Date of HDU creation (UTC)                    
STILVERS= '3.2-1   '           / Version of STIL software                       
STILCLAS= 'uk.ac.starlink.votable.FitsPlusTableWriter' / Author class in STIL so 
</code></pre>
<p>What should I choose to plot the light curve of one Quasar? Or are there other repositories for plotting light curves? Thanks for helping!</p>

CC BY-SA 4.0
2021-10-09T15:22:01.853Z
But SDSS doesn't produce quasar light curves? As the web page you have linked says - "The content of the SDSS-DR14 Quasar Catalog is described in Table 5 of Pâris et al. (2018). The detailed description of the data model is available here."
ProfRob
CC BY-SA 4.0
2021-10-09T16:24:51.533Z
Oh I see that now. Apologies.
mnuizhre
CC BY-SA 4.0
2021-10-09T16:25:44.270Z
Would you be able to tell me how can I obtain light curve of a Quasar for analysis purpose? I wish to learn from the light curve a theory i have worked out!
mnuizhre
CC BY-SA 4.0
2021-10-09T17:04:28.030Z
I suggest you reformulate a question along those lines.
ProfRob
CC BY-SA 4.0
2021-10-09T19:59:47.837Z
I tried to ask the specific new question [here](https://astronomy.stackexchange.com/questions/47020/obtaining-the-flux-time-plot-for-a-quasar).
mnuizhre
<quasars><light-curve>
Obtaining the Light curve of a a Quasar
mnuizhre
# Obtaining the Light curve of a a Quasar

(Asked by: username_0 on 2021-10-09)

So, I am relatively comfortable with handling $\textit{FITS}$ files and hence I choose Python for the following operation.
The thing is that I need to analyse some Quasar light curves and hence I went to the DR14Q data release of the SDSS Survey [here](https://www.sdss.org/dr14/algorithms/qso_catalog/) in order to obtain the information on the [Quasar Files](https://data.sdss.org/sas/dr14/eboss/qso/DR14Q/DR14Q_v4_4.fits) (Big file don't open on data).

When I opened this files header on Python, I obtain:

```
hdu_list = fits.open(file_pth)
hdu_list.info()

```

where file\_pth is the fits file location.

I obtain the following output:

```
Filename: /content/drive/MyDrive/RAD PRAC/SDSS.fits
No.    Name      Ver    Type      Cards   Dimensions   Format
  0  PRIMARY       1 PrimaryHDU      16   (7055,)   uint8   
  1  DR14Q_v4_4    1 BinTableHDU    328   526356R x 105C   [18A, D, D, J, I, J, I, 4A, D, D, 4A, D, D, D, I, D, D, D, K, K, K, K, K, K, I, I, I, 51J, 51J, 51J, 51A, D, D, I, A, I, I, A, 5D, 5D, 5D, 5D, D, 5D, D, D, D, D, D, D, D, D, D, D, D, E, D, D, D, D, D, D, E, I, D, D, E, I, D, D, E, I, D, D, D, D, D, D, D, D, D, D, D, D, D, D, D, D, D, 4A, 4A, D, E, D, D, D, D, D, D, D, D, I, D, D, D] 

```

Now, I try to open the file to see the whole array of data and I am confused out of these data given:

```
XTENSION= 'BINTABLE'           / binary table extension                         
BITPIX  =                    8 / 8-bit bytes                                    
NAXIS   =                    2 / 2-dimensional table                            
NAXIS1  =                 1505 / width of table in bytes                        
NAXIS2  =               526356 / number of rows in table                        
PCOUNT  =                    0 / size of special data area                      
GCOUNT  =                    1 / one data group                                 
TFIELDS =                  105 / number of columns                              
EXTNAME = 'DR14Q_v4_4'         / table name                                     
TTYPE1  = 'SDSS_NAME'          / label for column 1                             
TFORM1  = '18A     '           / format for column 1                            
TUNIT1  = '-       '           / units for column 1                             
TTYPE2  = 'RA      '           / label for column 2                             
TFORM2  = 'D       '           / format for column 2                            
TUNIT2  = 'deg     '           / units for column 2                             
TTYPE3  = 'DEC     '           / label for column 3                             
TFORM3  = 'D       '           / format for column 3                            
TUNIT3  = 'deg     '           / units for column 3                             
TTYPE4  = 'THING_ID'           / label for column 4                             
TFORM4  = 'J       '           / format for column 4                            
TUNIT4  = '-       '           / units for column 4                             
TTYPE5  = 'PLATE   '           / label for column 5                             
TFORM5  = 'I       '           / format for column 5                            
TUNIT5  = '-       '           / units for column 5                             
TTYPE6  = 'MJD     '           / label for column 6                             
TFORM6  = 'J       '           / format for column 6                            
TUNIT6  = '-       '           / units for column 6                             
TTYPE7  = 'FIBERID '           / label for column 7                             
TFORM7  = 'I       '           / format for column 7                            
TUNIT7  = '-       '           / units for column 7                             
TTYPE8  = 'SPECTRO '           / label for column 8                             
TFORM8  = '4A      '           / format for column 8                            
TUNIT8  = '-       '           / units for column 8                             
TTYPE9  = 'Z       '           / label for column 9                             
TFORM9  = 'D       '           / format for column 9                            
TUNIT9  = '-       '           / units for column 9                             
TTYPE10 = 'Z_ERR   '           / label for column 10                            
TFORM10 = 'D       '           / format for column 10                           
TUNIT10 = '-       '           / units for column 10                            
TTYPE11 = 'SOURCE_Z'           / label for column 11                            
TFORM11 = '4A      '           / format for column 11                           
TUNIT11 = '-       '           / units for column 11                            
TTYPE12 = 'Z_VI    '           / label for column 12                            
TFORM12 = 'D       '           / format for column 12                           
TUNIT12 = '-       '           / units for column 12                            
TTYPE13 = 'Z_PIPE  '           / label for column 13                            
TFORM13 = 'D       '           / format for column 13                           
TUNIT13 = '-       '           / units for column 13                            
TTYPE14 = 'Z_PIPE_ERR'         / label for column 14                            
TFORM14 = 'D       '           / format for column 14                           
TUNIT14 = '-       '           / units for column 14                            
TTYPE15 = 'ZWARNING'           / label for column 15                            
TFORM15 = 'I       '           / format for column 15                           
TUNIT15 = '-       '           / units for column 15                            
TTYPE16 = 'Z_PCA   '           / label for column 16                            
TFORM16 = 'D       '           / format for column 16                           
TUNIT16 = '-       '           / units for column 16                            
TTYPE17 = 'Z_PCA_ER'           / label for column 17                            
TFORM17 = 'D       '           / format for column 17                           
TUNIT17 = '-       '           / units for column 17                            
TTYPE18 = 'Z_MGII  '           / label for column 18                            
TFORM18 = 'D       '           / format for column 18                           
TUNIT18 = '-       '           / units for column 18                            
TTYPE19 = 'BOSS_TARGET1'       / label for column 19                            
TFORM19 = 'K       '           / format for column 19                           
TUNIT19 = '-       '           / units for column 19                            
TTYPE20 = 'ANCILLARY_TARGET1'  / label for column 20                            
TFORM20 = 'K       '           / format for column 20                           
TUNIT20 = '-       '           / units for column 20                            
TTYPE21 = 'ANCILLARY_TARGET2'  / label for column 21                            
TFORM21 = 'K       '           / format for column 21                           
TUNIT21 = '-       '           / units for column 21                            
TTYPE22 = 'EBOSS_TARGET0'      / label for column 22                            
TFORM22 = 'K       '           / format for column 22                           
TUNIT22 = '-       '           / units for column 22                            
TTYPE23 = 'EBOSS_TARGET1'      / label for column 23                            
TFORM23 = 'K       '           / format for column 23                           
TUNIT23 = '-       '           / units for column 23                            
TTYPE24 = 'EBOSS_TARGET2'      / label for column 24                            
TFORM24 = 'K       '           / format for column 24                           
TUNIT24 = '-       '           / units for column 24                            
TTYPE25 = 'N_SPEC_SDSS'        / label for column 25                            
TFORM25 = 'I       '           / format for column 25                           
TUNIT25 = '-       '           / units for column 25                            
TTYPE26 = 'N_SPEC_BOSS'        / label for column 26                            
TFORM26 = 'I       '           / format for column 26                           
TUNIT26 = '-       '           / units for column 26                            
TTYPE27 = 'N_SPEC  '           / label for column 27                            
TFORM27 = 'I       '           / format for column 27                           
TUNIT27 = '-       '           / units for column 27                            
TTYPE28 = 'PLATE_DUPLICATE'    / label for column 28                            
TFORM28 = '51J     '           / format for column 28                           
TUNIT28 = '-       '           / units for column 28                            
TTYPE29 = 'MJD_DUPLICATE'      / label for column 29                            
TFORM29 = '51J     '           / format for column 29                           
TUNIT29 = '-       '           / units for column 29                            
TTYPE30 = 'FIBERID_DUPLICATE'  / label for column 30                            
TFORM30 = '51J     '           / format for column 30                           
TUNIT30 = '-       '           / units for column 30                            
TTYPE31 = 'SPECTRO_DUPLICATE'  / label for column 31                            
TFORM31 = '51A     '           / format for column 31                           
TUNIT31 = '-       '           / units for column 31                            
TDIM31  = '(1,51)  '           / dimensions for column 31                       
TTYPE32 = 'BI_CIV  '           / label for column 32                            
TFORM32 = 'D       '           / format for column 32                           
TUNIT32 = 'km/s    '           / units for column 32                            
TTYPE33 = 'ERR_BI_CIV'         / label for column 33                            
TFORM33 = 'D       '           / format for column 33                           
TUNIT33 = 'km/s    '           / units for column 33                            
TTYPE34 = 'RUN_NUMBER'         / label for column 34                            
TFORM34 = 'I       '           / format for column 34                           
TUNIT34 = '-       '           / units for column 34                            
TTYPE35 = 'RERUN_NUMBER'       / label for column 35                            
TFORM35 = 'A       '           / format for column 35                           
TUNIT35 = '-       '           / units for column 35                            
TTYPE36 = 'COL_NUMBER'         / label for column 36                            
TFORM36 = 'I       '           / format for column 36                           
TUNIT36 = '-       '           / units for column 36                            
TTYPE37 = 'FIELD_NUMBER'       / label for column 37                            
TFORM37 = 'I       '           / format for column 37                           
TUNIT37 = '-       '           / units for column 37                            
TTYPE38 = 'OBJ_ID  '           / label for column 38                            
TFORM38 = 'A       '           / format for column 38                           
TUNIT38 = '-       '           / units for column 38                            
TTYPE39 = 'PSFFLUX '           / label for column 39                            
TFORM39 = '5D      '           / format for column 39                           
TUNIT39 = 'nanomaggies'        / units for column 39                            
TTYPE40 = 'IVAR_PSFFLUX'       / label for column 40                            
TFORM40 = '5D      '           / format for column 40                           
TUNIT40 = '-       '           / units for column 40                            
TTYPE41 = 'PSFMAG  '           / label for column 41                            
TFORM41 = '5D      '           / format for column 41                           
TUNIT41 = 'mag     '           / units for column 41                            
TTYPE42 = 'ERR_PSFMAG'         / label for column 42                            
TFORM42 = '5D      '           / format for column 42                           
TUNIT42 = 'mag     '           / units for column 42                            
TTYPE43 = 'MI      '           / label for column 43                            
TFORM43 = 'D       '           / format for column 43                           
TUNIT43 = '-       '           / units for column 43                            
TTYPE44 = 'GAL_EXT '           / label for column 44                            
TFORM44 = '5D      '           / format for column 44                           
TUNIT44 = 'mag     '           / units for column 44                            
TTYPE45 = 'RASS_COUNTS'        / label for column 45                            
TFORM45 = 'D       '           / format for column 45                           
TUNIT45 = 'counts/s'           / units for column 45                            
TTYPE46 = 'RASS_COUNTS_SNR'    / label for column 46                            
TFORM46 = 'D       '           / format for column 46                           
TUNIT46 = '-       '           / units for column 46                            
TTYPE47 = 'SDSS2ROSAT_SEP'     / label for column 47                            
TFORM47 = 'D       '           / format for column 47                           
TUNIT47 = 'arcsec  '           / units for column 47                            
TTYPE48 = 'FLUX_0.2_2.0keV'    / label for column 48                            
TFORM48 = 'D       '           / format for column 48                           
TUNIT48 = 'erg/s/cm2'          / units for column 48                            
TTYPE49 = 'FLUX_0.2_2.0keV_ERR' / label for column 49                           
TFORM49 = 'D       '           / format for column 49                           
TUNIT49 = 'erg/s/cm2'          / units for column 49                            
TTYPE50 = 'FLUX_2.0_12.0keV'   / label for column 50                            
TFORM50 = 'D       '           / format for column 50                           
TUNIT50 = 'erg/s/cm2'          / units for column 50                            
TTYPE51 = 'FLUX_2.0_12.0keV_ERR' / label for column 51                          
TFORM51 = 'D       '           / format for column 51                           
TUNIT51 = 'erg/s/cm2'          / units for column 51                            
TTYPE52 = 'FLUX_0.2_12.0keV'   / label for column 52                            
TFORM52 = 'D       '           / format for column 52                           
TUNIT52 = 'erg/s/cm2'          / units for column 52                            
TTYPE53 = 'FLUX_0.2_12.0keV_ERR' / label for column 53                          
TFORM53 = 'D       '           / format for column 53                           
TUNIT53 = 'erg/s/cm2'          / units for column 53                            
TTYPE54 = 'LUM_0.2_12.0keV'    / label for column 54                            
TFORM54 = 'D       '           / format for column 54                           
TUNIT54 = 'erg/s   '           / units for column 54                            
TTYPE55 = 'SDSS2XMM_SEP'       / label for column 55                            
TFORM55 = 'D       '           / format for column 55                           
TUNIT55 = 'arcsec  '           / units for column 55                            
TTYPE56 = 'GALEX_MATCHED'      / label for column 56                            
TFORM56 = 'E       '           / format for column 56                           
TUNIT56 = '-       '           / units for column 56                            
TTYPE57 = 'FUV     '           / label for column 57                            
TFORM57 = 'D       '           / format for column 57                           
TUNIT57 = '-       '           / units for column 57                            
TTYPE58 = 'FUV_IVAR'           / label for column 58                            
TFORM58 = 'D       '           / format for column 58                           
TUNIT58 = '-       '           / units for column 58                            
TTYPE59 = 'NUV     '           / label for column 59                            
TFORM59 = 'D       '           / format for column 59                           
TUNIT59 = '-       '           / units for column 59                            
TTYPE60 = 'NUV_IVAR'           / label for column 60                            
TFORM60 = 'D       '           / format for column 60                           
TUNIT60 = '-       '           / units for column 60                            
TTYPE61 = 'JMAG    '           / label for column 61                            
TFORM61 = 'D       '           / format for column 61                           
TUNIT61 = 'Vega    '           / units for column 61                            
TTYPE62 = 'ERR_JMAG'           / label for column 62                            
TFORM62 = 'D       '           / format for column 62                           
TUNIT62 = 'Vega    '           / units for column 62                            
TTYPE63 = 'JSNR    '           / label for column 63                            
TFORM63 = 'E       '           / format for column 63                           
TUNIT63 = '-       '           / units for column 63                            
TTYPE64 = 'JRDFLAG '           / label for column 64                            
TFORM64 = 'I       '           / format for column 64                           
TUNIT64 = '-       '           / units for column 64                            
TTYPE65 = 'HMAG    '           / label for column 65                            
TFORM65 = 'D       '           / format for column 65                           
TUNIT65 = 'Vega    '           / units for column 65                            
TTYPE66 = 'ERR_HMAG'           / label for column 66                            
TFORM66 = 'D       '           / format for column 66                           
TUNIT66 = 'Vega    '           / units for column 66                            
TTYPE67 = 'HSNR    '           / label for column 67                            
TFORM67 = 'E       '           / format for column 67                           
TUNIT67 = '-       '           / units for column 67                            
TTYPE68 = 'HRDFLAG '           / label for column 68                            
TFORM68 = 'I       '           / format for column 68                           
TUNIT68 = '-       '           / units for column 68                            
TTYPE69 = 'KMAG    '           / label for column 69                            
TFORM69 = 'D       '           / format for column 69                           
TUNIT69 = 'Vega    '           / units for column 69                            
TTYPE70 = 'ERR_KMAG'           / label for column 70                            
TFORM70 = 'D       '           / format for column 70                           
TUNIT70 = 'Vega    '           / units for column 70                            
TTYPE71 = 'KSNR    '           / label for column 71                            
TFORM71 = 'E       '           / format for column 71                           
TUNIT71 = '-       '           / units for column 71                            
TTYPE72 = 'KRDFLAG '           / label for column 72                            
TFORM72 = 'I       '           / format for column 72                           
TUNIT72 = '-       '           / units for column 72                            
TTYPE73 = 'SDSS2MASS_SEP'      / label for column 73                            
TFORM73 = 'D       '           / format for column 73                           
TUNIT73 = 'arcsec  '           / units for column 73                            
TTYPE74 = 'W1MAG   '           / label for column 74                            
TFORM74 = 'D       '           / format for column 74                           
TUNIT74 = '-       '           / units for column 74                            
TTYPE75 = 'ERR_W1MAG'          / label for column 75                            
TFORM75 = 'D       '           / format for column 75                           
TUNIT75 = '-       '           / units for column 75                            
TTYPE76 = 'W1SNR   '           / label for column 76                            
TFORM76 = 'D       '           / format for column 76                           
TUNIT76 = '-       '           / units for column 76                            
TTYPE77 = 'W1CHI2  '           / label for column 77                            
TFORM77 = 'D       '           / format for column 77                           
TUNIT77 = '-       '           / units for column 77                            
TTYPE78 = 'W2MAG   '           / label for column 78                            
TFORM78 = 'D       '           / format for column 78                           
TUNIT78 = '-       '           / units for column 78                            
TTYPE79 = 'ERR_W2MAG'          / label for column 79                            
TFORM79 = 'D       '           / format for column 79                           
TUNIT79 = '-       '           / units for column 79                            
TTYPE80 = 'W2SNR   '           / label for column 80                            
TFORM80 = 'D       '           / format for column 80                           
TUNIT80 = '-       '           / units for column 80                            
TTYPE81 = 'W2CHI2  '           / label for column 81                            
TFORM81 = 'D       '           / format for column 81                           
TUNIT81 = '-       '           / units for column 81                            
TTYPE82 = 'W3MAG   '           / label for column 82                            
TFORM82 = 'D       '           / format for column 82                           
TUNIT82 = '-       '           / units for column 82                            
TTYPE83 = 'ERR_W3MAG'          / label for column 83                            
TFORM83 = 'D       '           / format for column 83                           
TUNIT83 = '-       '           / units for column 83                            
TTYPE84 = 'W3SNR   '           / label for column 84                            
TFORM84 = 'D       '           / format for column 84                           
TUNIT84 = '-       '           / units for column 84                            
TTYPE85 = 'W3CHI2  '           / label for column 85                            
TFORM85 = 'D       '           / format for column 85                           
TUNIT85 = '-       '           / units for column 85                            
TTYPE86 = 'W4MAG   '           / label for column 86                            
TFORM86 = 'D       '           / format for column 86                           
TUNIT86 = '-       '           / units for column 86                            
TTYPE87 = 'ERR_W4MAG'          / label for column 87                            
TFORM87 = 'D       '           / format for column 87                           
TUNIT87 = '-       '           / units for column 87                            
TTYPE88 = 'W4SNR   '           / label for column 88                            
TFORM88 = 'D       '           / format for column 88                           
TUNIT88 = '-       '           / units for column 88                            
TTYPE89 = 'W4CHI2  '           / label for column 89                            
TFORM89 = 'D       '           / format for column 89                           
TUNIT89 = '-       '           / units for column 89                            
TTYPE90 = 'CC_FLAGS'           / label for column 90                            
TFORM90 = '4A      '           / format for column 90                           
TUNIT90 = '-       '           / units for column 90                            
TTYPE91 = 'PH_FLAGS'           / label for column 91                            
TFORM91 = '4A      '           / format for column 91                           
TUNIT91 = '-       '           / units for column 91                            
TTYPE92 = 'SDSS2WISE_SEP'      / label for column 92                            
TFORM92 = 'D       '           / format for column 92                           
TUNIT92 = 'arcsec  '           / units for column 92                            
TTYPE93 = 'UKIDSS_MATCHED'     / label for column 93                            
TFORM93 = 'E       '           / format for column 93                           
TUNIT93 = '-       '           / units for column 93                            
TTYPE94 = 'YFLUX   '           / label for column 94                            
TFORM94 = 'D       '           / format for column 94                           
TUNIT94 = 'W/m2/Hz '           / units for column 94                            
TTYPE95 = 'YFLUX_ERR'          / label for column 95                            
TFORM95 = 'D       '           / format for column 95                           
TUNIT95 = 'W/m2/Hz '           / units for column 95                            
TTYPE96 = 'JFLUX   '           / label for column 96                            
TFORM96 = 'D       '           / format for column 96                           
TUNIT96 = 'W/m2/Hz '           / units for column 96                            
TTYPE97 = 'JFLUX_ERR'          / label for column 97                            
TFORM97 = 'D       '           / format for column 97                           
TUNIT97 = 'W/m2/Hz '           / units for column 97                            
TTYPE98 = 'HFLUX   '           / label for column 98                            
TFORM98 = 'D       '           / format for column 98                           
TUNIT98 = 'W/m2/Hz '           / units for column 98                            
TTYPE99 = 'HFLUX_ERR'          / label for column 99                            
TFORM99 = 'D       '           / format for column 99                           
TUNIT99 = 'W/m2/Hz '           / units for column 99                            
TTYPE100= 'KFLUX   '           / label for column 100                           
TFORM100= 'D       '           / format for column 100                          
TUNIT100= 'W/m2/Hz '           / units for column 100                           
TTYPE101= 'KFLUX_ERR'          / label for column 101                           
TFORM101= 'D       '           / format for column 101                          
TUNIT101= 'W/m2/Hz '           / units for column 101                           
TTYPE102= 'FIRST_MATCHED'      / label for column 102                           
TFORM102= 'I       '           / format for column 102                          
TUNIT102= '-       '           / units for column 102                           
TTYPE103= 'FIRST_FLUX'         / label for column 103                           
TFORM103= 'D       '           / format for column 103                          
TUNIT103= 'mJy     '           / units for column 103                           
TTYPE104= 'FIRST_SNR'          / label for column 104                           
TFORM104= 'D       '           / format for column 104                          
TUNIT104= '-       '           / units for column 104                           
TTYPE105= 'SDSS2FIRST_SEP'     / label for column 105                           
TFORM105= 'D       '           / format for column 105                          
TUNIT105= 'arcsec  '           / units for column 105                           
DATE-HDU= '2017-12-08T23:27:28' / Date of HDU creation (UTC)                    
STILVERS= '3.2-1   '           / Version of STIL software                       
STILCLAS= 'uk.ac.starlink.votable.FitsPlusTableWriter' / Author class in STIL so 

```

What should I choose to plot the light curve of one Quasar? Or are there other repositories for plotting light curves? Thanks for helping!

**Tags:** quasars, light-curve

> **Comments:**
> **username_1**: But SDSS doesn't produce quasar light curves? As the web page you have linked says - "The content of the SDSS-DR14 Quasar Catalog is described in Table 5 of Pâris et al. (2018). The detailed description of the data model is available here."  
> **username_0**: Oh I see that now. Apologies.  
> **username_0**: Would you be able to tell me how can I obtain light curve of a Quasar for analysis purpose? I wish to learn from the light curve a theory i have worked out!  
> **username_1**: I suggest you reformulate a question along those lines.  
> **username_0**: I tried to ask the specific new question [here](https://astronomy.stackexchange.com/questions/47020/obtaining-the-flux-time-plot-for-a-quasar).  

---

## 1 answers

### Answer by username_2 on 2021-10-10. Score: 2 | Accepted answer

As described in Paris et al. 2018, in that catalog you don't have the info for creating light curves.
If you go like here: <http://skyserver.sdss.org/dr16/en/tools/chart/navi.aspx>
you can get the spectra of objects selecting the coordinates. However, to get light curves I think you need the raw data.

> **Comments:**
> **username_0**: I think this answers my question, thanks! As suggested by @username_1 as well, I asked the question regarding how to obtain the Raw data in another [question](https://astronomy.stackexchange.com/q/47020/44051). That I am still unsure of!  

---

