Short Period Pulsators (SPP)

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AAVSO Alert Notice 777 announces an observing campaign beginning immediately on the delta Sct variable EH Lib. Observations are critical now through at least the night of June 09/10. Please see the notice for details and instructions.

There are threads for this campaign under the following forums:

Following Dr Riess's suggestion in Saturday's webinar that a valuable contribution amateurs can make to the improvement of the Hubble 'constant' and the expansion rate/change of the universe would be to observe long period Cepheids I did a search in the fabulous VSX for DCEP with periods > 5d (and located north of -20d as I live in southern Canada, and south of +55 for the trees along my northern 'horizon') and I find that most of the stars are quite bright.

Hi,

What is the correct mathematical or physically method of determining the maximum of Delta-Scuti-Stars or HADS?

If I take the wohle lightcurve I get other results as I only take half of the lightcurve. Some collegues told me, only to take half of the LC, but is that only an opinion, or is there a physically proof somewhere?

• Does one take the whole LC, from the plateou (blue lines)?
• Does one take the whole LC, but only from ascent to descent?
• Does one take oly half of the LC (green line)

Bernhard

Hi,

DY PEG was one of my first observations. I have made a mistake with my first upload, I have submitted 2458721  with the false time. (1 hour corrected too much)

Now I have now uploaded the (+1h) corrected dataset. Some people have downloaded my false data from 2458721. 

(I became aware of this with actual DY PEG data, where the O-C was much different as from JD 2458721...  )

NOW:

Epoche    C                    O (WBEA)            O-C

I measured this high amplitude del Scu star during February and March with my 500mm refractor and Canon 450D. 
I calculated the two periods (first and second overtone of the radial pulsation) using VSTAR in good agreement with published literature data.

P1 = 0.17835 (0.17836, Cox. et al)
P2 = 0.14279 (0.14280)

Analysis of the amplitudes shows a strong variation with a mean of 0.501 and a standard deviation of 0.128

Data uploaded to the AAVSO database.

Hello! Just looking over my curves for DY HER and SZ HYA. B-V seems to narrow at minimum compared to maximum for these two stars.

    Is this a common feature of SPVs? Thank you and best regards.

Mike

I was looking at some TESS light curves for variables of different types and happened upon this interesting LC for NSV 18243 which is a composite of TESS sectors 9, 10 and 11.  I did an analysis of the deep drops every 4 or so days and obtained the phase plot shown which combines the TESS data with Hipparcos.  For the TESS data, the dips look like an EA, but I do not see them in the Hipparcos data.  Note that the period determined from ASAS3 and Hipparcos is 0.527 d for this star and that period does also occur in TESS.

Am learning the ropes and studying V0346 ORI.  I have attached a light curve and would appreciate any help.  In particular, the comp star 000-BKG-472 seems to have more variablity than my target.  I can not find additional info on 000-BKG-472.  Graph shows some seeing issues towards end of series.  Thanks

bryan e martin

Hi all

At some point I want to extend the Leavitt's Law plugin in VStar to allow for distance to variable types other DCEP to be determined.

Here's a paper for RR Lyr period luminosity relations from 2004 (Catelan et al) :

https://www.researchgate.net/publication/1799435_The_RR_Lyrae_Period-Lu…

The authors provide I,J,H,K,V band specific PL relations involving P (period) and Z (metalicity).

Hello all,

Maybe my request is kind of odd. Through the BSM observing section I have been observing AS Cas. This is a Cepheid B variable star that, as I see now with all of its kind, has not been observed very much or in some cases not at all.