AAVSO: American Association of Variable Star Observers

Proposal #79

Proposer (3053) Andrew Pearce (apearce6916@gmail.com) obscode: PEX
Assigned To(3663) Dirk Terrell
Date SubmittedJan. 6, 2018

V487 Vel is a DY Per star with limited observations within the AID dating back only to 2012. It is a star with limited information available based on a Simbad search. It was reported in Tisserand, et al (Astronomy and Astrophysics, volume 551A, 77-77 (2013)) based on an extensive analysis of ASAS data. It is listed Chen and Yang's atlas of galactic carbon stars (Astron. J., 143, 36 (2012)). There is some limited near-infrared photometry reported in the literature (Whitlock, et al MNRAS 369, 751-782 (2006)). Millimetre observations of V487 Vel obtained in 1999 and 2001 were reported in Groenewegen et al (Astronomy and Astrophysics, volume 390, 501-510 (2002)).

A literature search has found that there is no other multi colour photometry of this star over and and above the references listed above and the visual observations reported in the AID. VSX shows some JHK photometry from 2MASS and W photometry from AllWISE, however there does not appear to be any BVRI photometry reported.

Some time between July 2017 and November 2017, it underwent a fade from it's normal visual magnitude of around 9.5-10 to it's current level of around 11.5. This is the first recorded fading event based on observations in the AID.

It is proposed that multi-colour photometry (BVRI) is performed on the star at a cadence of approximately 5 days from now (January 2018) in it's current low state until such time as it recovers back to it's maximum state and has reached a steady state. This maybe a total duration of 1-2 years depending on the star's behaviour.

The most suitable telescope is MJUO telescope (OC61).

Target RA (H.HH) Dec (D.DD) Magnitude Telescope Observation Frequency Expiration Date Proprietary Term
V487 Vel 9.300444 -54.04094 14.0–9.0 No


(3663) Dirk Terrell — Jan. 9, 2018, 12:31 p.m.

Note from Arne from the TAC discussion:

"The bigger problem will be the carbon-star redness, which gives (B-V) = 3 and (V-I) ~ 6. That means it is very bright at Ic (or equivalently Sloan i'), and may not be doable at that wavelength with OC61. If approved, it might be useful to do a set of BVr'i' with OC61 and see what we get; and then consider doing BV with OC61 and r'i' with BSM_S (which will have the Sloan filters within a month)."

(3053) Andrew Pearce — Jan. 9, 2018, 1:32 p.m.

I recently measured V487 Vel which had B-V = 3.5 (V=10.6, B=14.1) and V-R = 1.6 (R=9.0)

(2911) Michael Nicholas — Sept. 26, 2018, 5:44 p.m.

Loaded in BSM_Berry

Comments on this proposal are closed.