Proposal #712

Proposer	(1546) Walt Cooney (waltc1111@gmail.com) obscode: CWT
Assigned To	(3663) Dirk Terrell
Date Submitted	July 14, 2026
Status	Allocated
Priority	Normal
Proposal	U Sco is one of 11 known galactic recurrent novae. It last erupted in 2022. Gordon Myers has been doing unfiltered photometry of the eclipses to determine times of minimum. Complimentary out of eclipse B and V monitoring is not being done however. I'd appreciate time on OC61 to do regular B and V measurements of this system to confirm the changes in Pdot that are indicated in Gordon's eclipse timings. The one measurement of U Sco in V this season was a measurement of approximately 18th magnitude. I ask for 7 x 3 min V exposures and 10 x 3min B exposures nightly or as often as possible. The season for U Sco is in decline this year so a number of measurements late in the season will help beat down the uncertainty in the system's lumniosity caused by flickering and normal out-of-eclipse magnitude variation. I ask for 3 minute subs but I do not know the typical OC61 drive performance so am unsure if that is an appropriate sub time. Thanks, Walt

Targets

Target Name	RA (H.HH)	Dec (D.DD)	Magnitude	Observation Frequency	Expiration Date	Proprietary Term
U Sco	16.375217	-17.87867	19.3–7.5	1	July 31, 2027	No

Plans currently in place

oc61/AAVSO_P712_CWT_AUTO.csv

# $Id: AAVSO_P712_CWT_AUTO.csv 5930 2026-08-08 19:36:56Z MZK $
#PROPOSAL=712
#REQUESTER=CWT,,vphot
#target,hh,mm,ss.ss,dd,mm,ss.s,desc,priority,monitor,maxX,nrepeat,bin,[filter,exposure,nexp],[filter,exposure,nexp]
U_Sco,16,22,30.78,-17,52,43.212,U_Sco,50,1,2,1,4,B,120,15,V,120,10,EarliestTime=2026-07-14T00:00:00,LatestTime=2027-07-31T00:00:00

Comments

(3663) Dirk Terrell — July 25, 2026, 4:28 p.m.: Arne suggests 2 minute subs.
(4726) Kenneth Menzies — July 28, 2026, 3:13 p.m.: Committed to oc61.
(1546) Walt Cooney — Aug. 2, 2026, 5:05 p.m.: With the change to two minute subs instead of three minute subs, please increase the number of subs by 3/2 so that the amount of total exposure time is the same.
(4848) George Silvis — Aug. 5, 2026, 6:16 p.m.: Did you get this comment in an email?
(1546) Walt Cooney — Aug. 5, 2026, 9:07 p.m.: No, haven't gotten an email George. I am writing this comment at 5:06PM EDT on Aug 5. Are you writing me from the future?
(1546) Walt Cooney — Aug. 5, 2026, 9:10 p.m.: OK. It shows my comment written at 5:06 PM EDT as being written at 9:07 PM. Must be GMT.
(4726) Kenneth Menzies — Aug. 8, 2026, 7:37 p.m.: # subs increased

Comments on this proposal are closed.