Short Period Pulsators (SPP)

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.