AAVSO: American Association of Variable Star Observers

Proposal #405

Proposer (46594) Kushal Sahare (ksh.sah@gmail.com) obscode: SKUB
Assigned To(3663) Dirk Terrell
Date SubmittedAug. 30, 2023

Name: Kushal Sahare
Obscode: SKUB

This is my second proposal for my semester long observational project for my university course at Swinburne Online Astronomy.
Use of this: Semester long observational course university project in Astronomy . The aim is variable star monitoring about 6/8 short period variables.

Star RA DEC Constellation Var Type Max Mag Min Mag Period Observing Cadence Observing Section Filter Mode

RR Cet 01h 32m 08s +1° 20' 30" Cet RRAB 9.15 V 10.1 V 0.55302836 50 SPP B, V
XZ Cyg 19h 32m 29s +56° 23' 17" Cyg RRAB/BL 8.9 V 10.16 V 0.4666 2.9 SPP B, V
AC And 23h 18m 02s +48° 46' 58" And RRD 10.7 V 11.9 V 0.7112376 1.5 SPP B, V
SZ Lyn 08h 09m 35s +44° 28' 17" Lyn HADS 9.08 V 9.72 V 0.12053492 50 SPP B, V
AK Cep 22h 28m 50s +58° 12' 39" Cep DCEP 10.86 V 11.52 V 7.23268 0.7 SPP B, V
DY Peg 23h 08m 51s +17° 12′ 56″ Peg SXPHE 10 V 10.56 V 0.0729261 7 SPP B, V

Target RA (H.HH) Dec (D.DD) Magnitude Telescope Observation Frequency Expiration Date Proprietary Term
RR Cet 1.535556 1.34167 10.1–9.15 BSM_NH2 1 March 13, 2024 No
XZ Cyg 19.541389 56.38806 10.16–8.9 BSM_NH2 1 March 13, 2024 No
AC And 23.300556 48.78278 11.9–10.7 BSM_NH2 1 March 13, 2024 No
SZ Lyn 8.159722 44.47139 9.72–9.08 BSM_NH2 1 March 13, 2024 No
AK Cep 22.480556 58.21083 10.86–11.52 BSM_NH2 1 March 13, 2024 No
DY Peg 23.147552 17.21556 10.56–10.0 BSM_NH2 1 March 13, 2024 No


(4726) Kenneth Menzies — Sept. 7, 2023, 1:37 p.m.

Please clarify your observing cadence listed in the table above? What are the units?

I assume you are trying to get a useful light curve of the short period pulsators in some reasonable period of time (semester project)?

(46594) Kushal Sahare — Sept. 8, 2023, 12:49 a.m.

Hi Kenneth

That is correct - I want to get a useful light curve of these SPP for a semester-long project. Please find the observing cadence for each of these stars below:

Star RA DEC Observing Cadence (days)
RR Cet 01h 32m 08s +1° 20' 30" 7
XZ Cyg 19h 32m 29s +56° 23' 17" 2
AC And 23h 18m 02s +48° 46' 58" 1.0
SZ Lyn 08h 09m 35s +44° 28' 17" 7
AK Cep 22h 28m 50s +58° 12' 39" 1.0
DY Peg 23h 08m 51s +17° 12′ 56″ 7


(46594) Kushal Sahare — Sept. 8, 2023, 12:50 a.m.

Sorry, it does not render the table as I expected. The observing cadences are (in days)
7, 2, 1, 7, 1, 7 respectively.


(3000) Sebastian Otero — Sept. 8, 2023, 3:20 a.m.

Kushal, I don't see a relation between these numbers and the period of each star.
And whgat do you mean with days? How many observations a night? These are mostly short period stars so one point per week is useless.
And the longest period one seems to be the one that you want to observe more often (1 d.)?
What do you mean by "cadence"?

(46594) Kushal Sahare — Sept. 9, 2023, 8:51 p.m.

Hi Sebastian,

Sorry about the confusion.

After reading other proposals, I found each filter's exposure time and frequency for each star mentioned above:

B: 6 sec, 2-3 images
V: 3 sec, 2-3 images

I got confused between the observation frequency each session and cadence. Cadence as per the AAVSO target tool, is how often a star should be observed.

(4726) Kenneth Menzies — Sept. 15, 2023, 5:45 p.m.

Plan committed to NH. I selected daily imaging (1 set per night) for all targets, which is close to what you requested.

Kushal: Your targets mainly have periods of a fraction of a day. Let's assume for this exercise that the period is 8 hours (0.3 days). How many images do you think you need to collect to define the lightcurve of these targets? How many images should you collect and over what period of time to do this efficiently? Based on the time frame of the project (semester), how many images do you think you will obtain IF you assume that due to weather you will only get images about every 3 days?

Keep in mind that these targets cover the entire northern sky. Will all of them be visible during our current season/night?

I'm not going to give you the answer since I feel that to run this project YOU should be making these decisions about cadence that will give you what you need in a timely fashion.

(46594) Kushal Sahare — Sept. 16, 2023, 6:22 p.m.

Hi Ken,

Thanks for your input. I put some thoughts into it after your suggestions.
Based on some research I did by reading online material and previous proposals, here is my update to this proposal:

RR Cet : B (60 sec) & V (30 sec) every 10 mins
XZ Cyg: B (60 sec) & V (30 sec) every 10 mins

AC And: This is an interesting one. I found that this is an irregular (shows multiple periods) variable. So I would like a time series data for this one. We can turn it off, once I am convinced that I have enough data for analysis. B and V filters.

SZ Lyn : Time series (can be removed later), B and V filter
AK Cep : B (60 sec) & V (30 sec) every 15 mins. This one is has long period.
DY Peg: Time series (can be removed later), B and V filter

I found that most of these stars peak (using https://airmass.org) for NH location in start of fall or have enough time for observation > 30deg except for SZ Lyn. But since SZ Lyn has very short period, enough observations can be captured.

Please suggest if I have missed something.


(46594) Kushal Sahare — Oct. 3, 2023, 12:40 a.m.

Hi Ken

Is there a way to update this observation according to my new proposal?

Please suggest.


(46594) Kushal Sahare — Nov. 20, 2023, 4:09 a.m.


The semester has concluded. I request to stop the observations for this proposal.


Comments on this proposal are closed.