(cba:news) V380 Oph (fwd)

Joe Patterson jop at astro.columbia.edu
Thu Jul 9 15:09:28 EDT 2015


Yes, this seems to be a *fresh* fading - so in theory, it's now a bare 
white dwarf and an orbiting M dwarf.  If the WD is hot (it should be), 
then the reflection effect off the M dwarf should produce a sinusoidal 
signal at Porb.  So the amplitude of the signal furnishes a bolometer 
for the WD.  It's an experiment we rarely get to do, because the 
accretion disk normally *shadows* the secondary from (most) WD light.

So it's a great target for time-series photometry.  Unfiltered is OK 
(perhaps necessary), but something redder (R?) might be better.

joe

On 7/9/2015 2:21 PM, Matthew Templeton wrote:
> Good afternoon Joe,
>
> I wanted to send a quick followup regarding V380 Oph.  Stella and I were
> talking this morning and are considering putting out a special notice on
> this star.  Do you have any thoughts or requests for what you'd like?
>
> I don't know that there are any multiwavelength followups or
> spectroscopy planned, but given that we don't have any data in the AAVSO
> database of this star at minimum, it would be good for posterity's sake
> if people are encouraged to get some data.  We currently have a little
> bit of data by Gordon Myers and Lew Cook from the past couple of days --
> the variations phase on the orbital period (0.154d) so they're doing a
> good job of detecting it.  The clear filter amplitude is about a
> magnitude, 19.3 to 18.8 for what looks like a sinusoid, with some bright
> deviations up to 18.4 or so.
>
> Let us know if you have any requests, otherwise Elizabeth Waagen and/or
> I will get something out Friday AM.
>
>      Matt
>
> Matthew Templeton, Ph.D.
> Science Director
> American Association of Variable Star Observers
> -----------------------------------------------
> Please support the AAVSO and its mission --
> Join or donate today: http://www.aavso.org/apps/donate
>
>
> ---------- Forwarded message ----------
> Date: Wed, 8 Jul 2015 10:31:32 -0400 (EDT)
> From: Matthew Templeton <matthewt at aavso.org>
> To: Joe Patterson <jop at astro.columbia.edu>
> Cc: eowaagen at aavso.org, sara at aavso.org
> Subject: V380 Oph
>
> Good morning Joe,
>
> I hope this email finds you well & enjoying summer.
>
> We received an email from Adolfo Darriba this morning about V380 Oph and
> he mentioned an Alert we sent out three years ago for an HST program on
> this.  As far as I've heard there isn't anything in the pipeline, but I
> wanted to check in case you need us to put something out -- we'll be
> happy to do so, just give us the typical details of what's needed when.
>
> Clear skies,
>
>      Matthew
>
> Matthew Templeton, Ph.D.
> Science Director
> American Association of Variable Star Observers
> -----------------------------------------------
> Please support the AAVSO and its mission --
> Join or donate today: http://www.aavso.org/apps/donate
>

____________________________________________________________
Center for Backyard Astrophysics (CBA) mailing lists
http://cbastro.org/communications/mailing-lists/ 



More information about the cba-public mailing list