<p>HST took pictures close to periastron in 1997, when the separation of the stars was about 3.7 arcsecs. See <a href="http://iopscience.iop.org/article/10.3847/1538-4357/aa6af8/meta" rel="nofollow noreferrer">Bond et al. (2017)</a>. There are no pictures exactly at periastron.</p>

<p>HST took pictures close to apastron in August 2016, when the separation was 10.7 arcsecs (see the same reference). There are no pictures from HST closer to apastron but some may be taken over the next year or so.</p>

<p>Here is a raw HST image from August 2016, taken from the <a href="https://hla.stsci.edu/hlaview.html#Inventory%7CfilterText%3D%24filterTypes%3D%7Cquery_string=Sirius%20&amp;posfilename=&amp;poslocalname=&amp;posfilecount=&amp;listdelimiter=whitespace&amp;listformat=degrees&amp;RA=101.287155&amp;Dec=-16.716116&amp;Radius=0.200000&amp;inst-control=all&amp;inst=ACS&amp;inst=ACSGrism&amp;inst=WFC3&amp;inst=WFPC2&amp;inst=NICMOS&amp;inst=NICGRISM&amp;inst=COS&amp;inst=WFPC2-PC&amp;inst=STIS&amp;inst=FOS&amp;inst=GHRS&amp;imagetype=best&amp;prop_id=&amp;spectral_elt=&amp;proprietary=both&amp;preview=1&amp;output_size=256&amp;cutout_size=12.8%7Cra=&amp;dec=&amp;sr=&amp;level=&amp;image=&amp;inst=ACS%2CACSGrism%2CWFC3%2CWFPC2%2CNICMOS%2CNICGRISM%2CCOS%2CWFPC2-PC%2CSTIS%2CFOS%2CGHRS&amp;ds=" rel="nofollow noreferrer">HST archive</a>  (freely available and easy to find).</p>

<p><a href="https://i.sstatic.net/j9AOo.jpg" rel="nofollow noreferrer"><img src="https://i.sstatic.net/j9AOo.jpg" alt="HST image of Sirius AB"></a></p>

<p>There are many photographs of the binary taken at around 11 arcseconds separation. Table~3 of the same reference above lists a stack of observations taken between 1970 and 1975 when the separation was around 11 arcseconds. One of these images is shown below; Sirius B is the faint object below and to the right of Sirius A. The other symmetrically spaced blobs are image artefacts.</p>

<p><a href="https://i.sstatic.net/IvKmq.png" rel="nofollow noreferrer"><img src="https://i.sstatic.net/IvKmq.png" alt="Sirius AB"></a></p>

CC BY-SA 4.0
2018-10-24T06:40:36.053Z
2018-10-24T20:12:10.227Z
2018-10-24T20:12:10.227Z
ProfRob
<p>Sirius B has a distance to Sirius A of 11 arc seconds at apastron; are there any good images of it at that point in its orbit?</p>

<star><binary-star>
Are there any good images of Sirius B at apastron in the Sirius system?
user24634
# Are there any good images of Sirius B at apastron in the Sirius system?

(Asked by: username_0 on 2018-10-24)

Sirius B has a distance to Sirius A of 11 arc seconds at apastron; are there any good images of it at that point in its orbit?

**Tags:** star, binary-star


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## 1 answers

### Answer by username_1 on 2018-10-24. Score: 2

HST took pictures close to periastron in 1997, when the separation of the stars was about 3.7 arcsecs. See [Bond et al. (2017)](http://iopscience.iop.org/article/10.3847/1538-4357/aa6af8/meta). There are no pictures exactly at periastron.

HST took pictures close to apastron in August 2016, when the separation was 10.7 arcsecs (see the same reference). There are no pictures from HST closer to apastron but some may be taken over the next year or so.

Here is a raw HST image from August 2016, taken from the [HST archive](https://hla.stsci.edu/hlaview.html#Inventory%7CfilterText%3D%24filterTypes%3D%7Cquery_string=Sirius%20&posfilename=&poslocalname=&posfilecount=&listdelimiter=whitespace&listformat=degrees&RA=101.287155&Dec=-16.716116&Radius=0.200000&inst-control=all&inst=ACS&inst=ACSGrism&inst=WFC3&inst=WFPC2&inst=NICMOS&inst=NICGRISM&inst=COS&inst=WFPC2-PC&inst=STIS&inst=FOS&inst=GHRS&imagetype=best&prop_id=&spectral_elt=&proprietary=both&preview=1&output_size=256&cutout_size=12.8%7Cra=&dec=&sr=&level=&image=&inst=ACS%2CACSGrism%2CWFC3%2CWFPC2%2CNICMOS%2CNICGRISM%2CCOS%2CWFPC2-PC%2CSTIS%2CFOS%2CGHRS&ds=) (freely available and easy to find).

[![HST image of Sirius AB](https://i.sstatic.net/j9AOo.jpg)](https://i.sstatic.net/j9AOo.jpg)

There are many photographs of the binary taken at around 11 arcseconds separation. Table~3 of the same reference above lists a stack of observations taken between 1970 and 1975 when the separation was around 11 arcseconds. One of these images is shown below; Sirius B is the faint object below and to the right of Sirius A. The other symmetrically spaced blobs are image artefacts.

[![Sirius AB](https://i.sstatic.net/IvKmq.png)](https://i.sstatic.net/IvKmq.png)


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