[Date Prev][Date Next][Date Index]

Re: (cba:news) V380 Oph (fwd) (Joe Patterson) [2015-07-09T19:10:28Z]

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@xxxxxxxxx>
To: Joe Patterson <jop@xxxxxxxxxxxxxxxxxx>
Cc: eowaagen@xxxxxxxxx, sara@xxxxxxxxx
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
https://cbastro.org/communications/mailing-lists/