<p>What exactly is meant by <em>spurious periods of stars</em>? E. Tanner writes in <em><a href="http://adsabs.harvard.edu/full/1948JRASC..42..177T" rel="nofollow noreferrer">Spurious Periods in Spectroscopic Binaries</a></em> in 1948</p>
<p><a href="https://i.sstatic.net/X4rN4.png" rel="nofollow noreferrer"><img src="https://i.sstatic.net/X4rN4.png" alt="enter image description here" /></a></p>
<p>Furthermore: Can spurious periods be produced by aliasing, and how can they be handled? I read about this that these periods can be detected while using Robust variogram estimator in <a href="https://ui.adsabs.harvard.edu/abs/1999A%26AS..136..421E/abstract" rel="nofollow noreferrer">this paper</a>.</p>

CC BY-SA 4.0
2021-07-07T04:35:56.667Z
Spurious periods caused by aliasing happen all the time especially in Fourier based period searching. Sometimes they can be hard to disentangle from the "real" period especially if the "real" period is near a multiple of nice fraction of a day. One test is to do a Fourier transform of the observation times, see if the proposed period is also indicated by the spectrogram/periodogram. This is the window function. The other term to look out for are beat periods. Can't point you a specific modern example. Most researchers are now aware of the problem(s).
TazAstroSpacial
CC BY-SA 4.0
2021-05-23T17:16:59.307Z
Are you referring to this http://adsabs.harvard.edu/full/1948JRASC..42..177T
James K
CC BY-SA 4.0
2021-05-23T18:58:51.997Z
Yes, I am referring to this concept.
Junaid Ihsan
CC BY-SA 4.0
2021-05-23T20:47:14.533Z
Welcome to astronomy SE! To avoid down- and close-votes, please follow the guidelines [ask]. It would be great if you could edit-in the reference @JamesK mentioned plus the relevant quote from it.
B--rian
CC BY-SA 4.0
2021-05-23T20:53:42.093Z
To give you an idea what I am talking about, I edit your question a bit, but further improvements (and details) from your side would be beneficial.
B--rian
CC BY-SA 4.0
2021-05-24T06:34:38.237Z
Thank you for your editing, I also edit it according to my understandings.
Junaid Ihsan
CC BY-SA 4.0
2021-05-24T06:54:41.817Z
Uhm... in the following paragraph that very paper explains exactly what the author mean with "spurious periods". In essence it's a polite way of "wrongly measured" or "badly analysed, thus wrong"
planetmaker
CC BY-SA 4.0
2021-05-24T07:09:59.813Z
Hmm, got it, thanks
Junaid Ihsan
CC BY-SA 4.0
2021-05-24T21:00:25.183Z
@JunaidIhsan yes I also am pretty sure that spurious is just polite for erroneous, i.e. bad data. But your question "Can spurious periods be produced by aliasing?" is a great one! You can consider just posting a short answer here yourself explaining that you now agree with comments that "spurious is just polite for erroneous" and you can accept it also, then post a new question "Can spurious periods be produced by aliasing?", or you could just modify this one and remove all the references to the old paper, or just say that it's background, what got you thinking about ailiasing.
uhoh
CC BY-SA 4.0
2021-05-24T21:01:51.930Z
You could also ask a question like "Have there been famous or demonstrative examples of aliasing leading to spurious periods in more modern settings than this paper from 1948?"
uhoh
<observational-astronomy><binary-star><photometry><variable-star><hipparcos>
Spurious periods of stars
Junaid Ihsan
# Spurious periods of stars

(Asked by: username_0 on 2021-05-23)

What exactly is meant by *spurious periods of stars*? E. Tanner writes in *[Spurious Periods in Spectroscopic Binaries](http://adsabs.harvard.edu/full/1948JRASC..42..177T)* in 1948

[![enter image description here](https://i.sstatic.net/X4rN4.png)](https://i.sstatic.net/X4rN4.png)

Furthermore: Can spurious periods be produced by aliasing, and how can they be handled? I read about this that these periods can be detected while using Robust variogram estimator in [this paper](https://ui.adsabs.harvard.edu/abs/1999A%26AS..136..421E/abstract).

**Tags:** observational-astronomy, binary-star, photometry, variable-star, hipparcos

> **Comments:**
> **username_2**: Are you referring to this http://adsabs.harvard.edu/full/1948JRASC..42..177T  
> **username_0**: Yes, I am referring to this concept.  
> **username_3**: Welcome to astronomy SE! To avoid down- and close-votes, please follow the guidelines [ask]. It would be great if you could edit-in the reference @username_2 mentioned plus the relevant quote from it.  
> **username_3**: To give you an idea what I am talking about, I edit your question a bit, but further improvements (and details) from your side would be beneficial.  
> **username_0**: Thank you for your editing, I also edit it according to my understandings.  
> **username_4**: Uhm... in the following paragraph that very paper explains exactly what the author mean with "spurious periods". In essence it's a polite way of "wrongly measured" or "badly analysed, thus wrong"  
> **username_0**: Hmm, got it, thanks  
> **username_5**: @username_0 yes I also am pretty sure that spurious is just polite for erroneous, i.e. bad data. But your question "Can spurious periods be produced by aliasing?" is a great one! You can consider just posting a short answer here yourself explaining that you now agree with comments that "spurious is just polite for erroneous" and you can accept it also, then post a new question "Can spurious periods be produced by aliasing?", or you could just modify this one and remove all the references to the old paper, or just say that it's background, what got you thinking about ailiasing.  
> **username_5**: You could also ask a question like "Have there been famous or demonstrative examples of aliasing leading to spurious periods in more modern settings than this paper from 1948?"  
> **username_1**: Spurious periods caused by aliasing happen all the time especially in Fourier based period searching. Sometimes they can be hard to disentangle from the "real" period especially if the "real" period is near a multiple of nice fraction of a day. One test is to do a Fourier transform of the observation times, see if the proposed period is also indicated by the spectrogram/periodogram. This is the window function. The other term to look out for are beat periods. Can't point you a specific modern example. Most researchers are now aware of the problem(s).  

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