AAVSO: American Association of Variable Star Observers

Proposal #139

Proposer (34230) Christopher Colvin (christopher.colvin.1992@gmail.com) obscode: CCHC
Assigned To(3663) Dirk Terrell
Date SubmittedApril 15, 2020

Good evening,

I am requesting that the targets listed be observed with the OC61 telescope on a daily basis for as long as the committee will allow. This is part of a independent research project of YSO's, particularly focusing on UXOR stars and attempting to better understand the similarities and differences in these five UXOR targets.

These five targets have not been reported to the AAVSO between eight months and one year; with the exception of KK Oph which was observed only about a week ago in TG. The remainder of these objects only have spotty observations reported to the AAVSO, or mostly visual and I would like to correct that with a long term observing program that will also gather data for a research paper I plan on submitting to the JAAVSO.

I request that the measurements be made in both V, B, and R filters in order to gather as much data as possible on these objects since they have been lacking in recent times.
Most of the targets rise around the same time with a couple outliers...

V0856 Sco 10:03 UTC

KK Oph 11:43 UTC

GSC 05107-00266 14:30 UTC

XX Sct 14:32 UTC

VV Ser 14:59 UTC

I request that all five of these get nightly (or at least every five nights) observations in all three filters V, B, and R if possible.

This campaign of observing these UXOR's will also serve as an "early warning" if these stars were to erupt or display any sort of unusual behavior. It would be a matter of alerting the YSO forum on the AAVSO page to get further follow up observations from other telescopes. This would allow for correction of systematic or equipment errors.

Thank you for your time and consideration of this proposal.

Christopher Colvin

Target RA (H.HH) Dec (D.DD) Magnitude Telescope Observation Frequency Expiration Date Proprietary Term
V0856 Sco 16.142858 -39.10508 8.44–6.64 OC61 1 Oct. 15, 2020 No
GSC 05107-00266 18.457244 -4.57986 13.2–10.96 OC61 1 Oct. 15, 2020 No
XX Sct 18.660275 -6.71825 16.6–13.0 OC61 1 Oct. 15, 2020 No
VV Ser 18.479964 0.14442 13.6–11.5 OC61 1 Oct. 15, 2020 No
KK Oph 17.168922 -27.25525 12.7–9.7 OC61 1 Oct. 15, 2020 No


(3663) Dirk Terrell — April 16, 2020, 9:58 a.m.

The TAC is considering this proposal. One concern is having good comparison stars in the fields, seeing as these types of object are found together and thus the other stars in the field may also be variable. We'd like the proposer to evaluate the fields carefully and give us offsets in the field centers to maximize the number of potential comparison stars. We like the scientific aspects of the proposal.

(34230) Christopher Colvin — April 16, 2020, 9:32 p.m.

Mr. Terrell et al;

Please see below for center of image offsets that have the best number of comp stars available for each object.

V0856 Sco: RA 16:07:38.2 // DEC -39:05:59.2 (Based on CCD Chart X25275IL)

GSC 05107-00266: I believe this one seems to have an acceptable number of comps; but if it must be changed: RA 18:27:16.93 // DEC -04:23:17.0 (Based on Chart X25275IY)

XX Sct: RA 18:39:22.06 // DEC -06:41:02.7 (Based on CCD Chart X25275JA)

VV Ser: RA 18:28:17.41 // DEC 00:12:26.3 (Based on CCD Chart X25275JC)

KK Oph: RA 17:09:45.83 // DEC -27:20:15.0 (Based on CCD Chart X25275JE)


I hope the TAC sees these changes made to the field center offsets as acceptable to better enable quality data to be obtained by this observing program.

Thank you for your time.

(4726) Kenneth Menzies — April 18, 2020, 1:13 p.m.

Plan created. Committed to OC61. Used revised RA/Dec.

(34230) Christopher Colvin — May 18, 2020, 9:19 p.m.

Requesting that data for all objects be imaged in V and B only since OC61 doesn't have an Rc filter.
SI and SR produce far too many WCS errors and data that is not usable.

Requesting that each target get 3 V images and 3 B images for a total of 6 images per target.

Thank you.

(34230) Christopher Colvin — June 10, 2020, 2:47 p.m.

Cancel above request for cancelling SI and SR since we now have TC's.

Now requesting that VV Ser be set back to the original RA 18.4799638889 DEC 0.144416666667 due to it not being in the FOV of the telescope.
I would rather have fewer comps than no variable target.

Thank you.

Comments on this proposal are closed.