AAVSO: American Association of Variable Star Observers

Proposal #93

Proposer (18792) Joseph Kalen (Jkalen3345@comcast.net) obscode: KLN
Assigned To(3663) Dirk Terrell
Date SubmittedDec. 8, 2018

Requester: Joseph Kalen
membership: Member (Sustaining)
obscode: KLN
e-mail address: JKalen3345@comcast.net

In two recent articles [Percy JR, Sparsely-Observed Pulsating Red Giants in the AAVSO Observing Program, JAAVSO, 46, 65-69, 2018] and [Karlsson T, et. al, 50 Forgotten Miras, JAAVSO, 44, 156-163, 2016] both authors list many pulsating red giant stars that are not regularly observed. Karlsson et.al demonstrated that additional observa-tions of these pulsating red giants can change the star classification, as demonstrated in the carbon star IV Peg, changed to SRa in the AAVSO database VSX.

Reviewing the AAVSO LCGv2 data for three stars referred to in Percy 2018, one star within each star classification, (IV Peg, V521 Ori, and V360 Peg), there has been some V data, but a lack of B, Rc and Ic band data.
This proposal is to add these photometric bands at least through two full cycles for the analysis of these red giants.

Users plan for the data: AAVSO database
Request image upload to VPHOT: Yes
Filters: B-Johnson, V-Johnson, R-cousins, I-cousins; (60, 30, 24, 21) sec, For V360 Peg (30, 15, 12, 11 sec)
Filter sequence: B, B, V, V, R, R, I, I, I, I, R, R, V, V, B, B

Target; Classification; Period (d); Requested site; Cadence; Note (Percy 2018)
IV Peg; SRa; 214.0; BSM_Berry; Weekly; new period gives a better phase curve than previous VSX
V360 Peg; SR; 44.9; BSM_Berry; Weekly; RV Tau weak evidence
V521 Ori; SRb; 221; BSM_NM; Weekly; new period gives a better phase curve than previous VSX

Start plan as soon as possible and extend observations of the three targets through March 2021.

Target RA (H.HH) Dec (D.DD) Magnitude Telescope Observation Frequency Expiration Date Proprietary Term
IV Peg 22.748133 18.11544 12.4–9.7 No
V360 Peg 23.808433 30.52747 8.6–8.0 1 Year
V521 Ori 5.738683 11.81319 12.4–10.9 No


(2911) Michael Nicholas — Dec. 10, 2018, 6:14 p.m.

It was pointed out by Arne that because IV Peg (B-V= 3.88) and V521 Ori (B-V= 1.98) are so red the exposures should be scaled by 50% of V for the R filter and 25% of V for the I filter.

(18792) Joseph Kalen — Jan. 30, 2020, 5:10 p.m.


Thank you for the BSM_S images of V0521_Ori (dated 1/25/2020).
The I-filter exposure (10 s) is the same as the other BSM sites and results in a SNR of 92.
A mean of the 8 B-filters results in a SNR of 26 for an exposure of 80 sec, also the same exposure as the other BSM sites.

These exposures and SNR are reasonable.

Thank you;

Joseph Kalen

Comments on this proposal are closed.