Short Period Pulsators (SPP)

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Information on the Observation and analysis of short period pulsators such as Cepheids and RR Lyrae.

26 123 By gilchrist.alle… 3 days 8 hours ago

Strange light curves for Tyc 3603-1124-1

American Association of Variable Star Observers (AAVSO)
gilchrist.alle… Tue, 09/19/2023 - 00:44

I've taken over 1400 B- and V-filter CCD photometric measurements of Tyc 3603-1124-1 beginning in September, 2021 and continuing within the last month.  The results look very strange to me.  VSX lists the star as a HADS variable, but the rise to brightness is slower than the fall.  PTD analysis yields a period, P=0.1359594542 d, very close to the value listed in VSX, P = 0.1359594542 d.  Fourier analysis results show only a fundamental f

New work on Polaris

American Association of Variable Star Observers (AAVSO)
bskiff Mon, 09/11/2023 - 01:34

     If anyone needs inspiration to observe (or continue observing) Polaris, a new paper by Willy Torres (Harvard) that appeared on astro-ph late last week may provide it:

Though this deals mainly with the radial velocities, it is clear that high-quality photometry remains useful, and is analyzed here in context with the rv's.  The introduction of the paper provides a comprehensive overview of the observational history of the star.  The writing, data analysis etc in this paper are fabulous, and characteristic of Torres' work.

Classification of CSS_J032404.3+211344

American Association of Variable Star Observers (AAVSO)
astrobrandx Wed, 06/28/2023 - 08:46

I am studying CSS_J032404.3+211344 for my master's project and trying to find a clear classification for it.

I chose this target rather arbitrarily based on observability for the Liverpool Telescope (LT) over a period last year and have some limited observations (16 each in g and r band) from whch I have done some basic analysis.  I found out there is some good V-band photometry data in the ASA-SN catalogue: 

CHOICE course on Variable Star Classification/Light Curves

American Association of Variable Star Observers (AAVSO)
weo Wed, 05/31/2023 - 21:06

(SPP forum)

  • Are you trying to determine what type of variable star you are looking at?
  • Interested in data mining but don't know the basics about variables?
  • New to variable stars and want to learn about the types AAVSOers observe?

There are spaces available in the excellent AAVSO CHOICE course "Variable Star Classification and Light Curves". This course, taught by Blake Crosby,
begins Monday, June 5, and runs through July 2. Register before June 4.

DCEPs - Observing Bright DCEPs

American Association of Variable Star Observers (AAVSO)
YPFA Wed, 02/15/2023 - 00:42

I would like to make some observations of T Mon (6.62-5.58V) and RT Aur (5.82-5.0V) and capture them on a CCD.

For various reasons (including availability of filters) I have opted to use iTelescope's T5, which is located in Utah, and uses a Takahashi Epsilon 250 (presumably 10-inches of aperture). The attached camera is an SBIG ST-10XME.  

Question about "2023 AAVSO RR Lyrae Ephemeris"

American Association of Variable Star Observers (AAVSO)
btschumy Sun, 02/05/2023 - 15:34

I was trying to use the SPP RR Lyrae Ephemeris of plan an imaging session.  I can't see how the predicted "time of maximum" lines up with the ephemeris you get from VSX.

For example, I was considering RR Gem for tonight.  Here is what the SPP ephemeris says for the days around tonight (Feb 5th in local time)

4-5     7.0

5-6     2.0

6-7     6.5

I would think I would use the 5-6 line and in my time zone (-7 UTC), that would be 7 PM on the 5th.

However, if I look at the VSX ephemeris, I see:

2459980.345   04 Feb 2023 20:16

Absolute Magnitude determination for Delta Scuti variables

American Association of Variable Star Observers (AAVSO)
PaviKSH Wed, 11/16/2022 - 19:19

I've tried to use the Period-Luminosity relation formula which I found on " " but it seems to be quite unaccurate. Do you have some other more precise way to calculate the absolute magnitude of a Delta Scuti variable?


Cepheid Images needed for photometry & period determination

American Association of Variable Star Observers (AAVSO)
PaviKSH Wed, 11/09/2022 - 11:08

I'm working on a school project and I have to determine periods of different types of variable stars in order to calculate the distance. For this reason I am looking for images of different variables stars like Cepheids and eclipsing binaries. A data set with at least two visible visible peaks is needed and the more images you have the better! All kind of Cepheids are welcome, stars like RR-Lyrae-type, Mira-type, long period/short period, delta-scuti-stars.

I'm really thankful for any data set you are able to provide.