Proposal #435

Proposer	(35150) Dr. Pradip Karmakar (pradipkarmakar39@gmail.com) obscode: KPRB
Assigned To	(3663) Dirk Terrell
Date Submitted	Oct. 15, 2023
Status	Declined
Priority	Normal
Proposal	Sir, Regarding the proposal # 391 , I am requesting to get some images of M31 V0619 ( M31_V1 , type - DCEP ) one more time in this month . I have came to know from AAVSO home page about the 100 years of M31-V1. I am requesting for some images of this cepheid in R- filter with exposure time 45 minutes- 60 minutes . Then hopefully we could reach the SNR nearly 20. Best regards Pradip Karmakar (KPRB)

Targets
Target	RA (H.HH)	Dec (D.DD)	Magnitude	Telescope	Observation Frequency	Expiration Date	Proprietary Term
M31 V0619	0.690920	41.16958	19.8–18.5	—	—	—	No

Comments

(4726) Kenneth Menzies — Oct. 16, 2023, 8:51 p.m.

How do you propose that we use an exposure of 45 minutes???? Tracking!!

Want to clarify?

(3663) Dirk Terrell — Oct. 16, 2023, 8:56 p.m.

Yeah, you'd have to stack images to get there.

(35150) Dr. Pradip Karmakar — Oct. 17, 2023, 6:15 p.m.

Dear Sir,
I came to regarding the above information from this link: https://www.aavso.org/aavso-alert-notice-422
(.... M31_V1 is magnitude 19.4V, so unfortunately it is not suitable for visual or photoelectric observers, but is a good target for CCD observers. The B-V = +1.28, period is 30.41 days, and amplitude ~ 1.2 magnitudes in B, likely smaller in V. Five nights of data obtained by Arne Henden, AAVSO, show that the variable appears to have peaked on JD 2455367 (2010 June 19) at about R=18 and as of July 2 was on its way down.

It is recommended that observers use either an Rc filter or observe unfiltered. About an hour or more of exposure per integration will be required to reach S/N = 20, depending on your equipment and sky brightness; multiple exposures and stacking might be necessary to avoid saturating the background.....).
With regards,
Pradip Karmakar

(3663) Dirk Terrell — Oct. 25, 2023, 4:08 p.m.

I was very concerned about this proposal from the beginning. It is important to understand the limits of your equipment and this is pushing well beyond what we can reliably do with the AAVSOnet telescopes. If I had a research interest in this telescope, I would realistically be looking at a 1.5m to 2.0m telescope to get useful data. Using AAVSONet means you need lots of exposure time and that has negative impacts on the other users of the systems, only to get S/N=20 data.

(35150) Dr. Pradip Karmakar — Oct. 26, 2023, 3:46 p.m.

Dear Dirk,
I have understand your suggestions. I would accept your decisions which you think better. Is there any way to communicate with " a 1.5m to 2.0m telescope "? Actually I am very much eager to do the photometry of M31_V1.
With regards,
Pradip Karmakar

(3663) Dirk Terrell — Oct. 26, 2023, 3:52 p.m.

I see that I said "If I had a research interest in this telescope ...". I meant "If I had a research interest in this object ...". As for getting time on a larger telescope, the AAVSO does not have access to such an instrument. You might look into commercial telescope rental sites or Las Cumbres: https://lco.global/

(35150) Dr. Pradip Karmakar — Oct. 26, 2023, 4:02 p.m.

Thank you for your suggestions.

Comments on this proposal are closed.