(cba:news) ATel 6676, and other targets

Joe Patterson jop at astro.columbia.edu
Sun Nov 9 04:49:51 EST 2014


Dear CBAers,

The hits just keep on rolling, for the ASAS-SN discoveries.  This one is 
very bright and pretty likely (not certain, confirmation needed) to be a 
CV.  Somewhat out of season, so try for as long as possible - and 
hopefully with Europe-USA handoffs.

Midterm exams, my New York conference (cbastro.org/workshop/), and grant 
applications have been taking their toll.  Not done yet, but let's 
update the night-sky hits:

Stars important to cover before they say goodbye for the year:

V Sge.  Very little data this year.  We need eclipse timings.

DQ Her.  Timings of the 71 s pulsation.  So to contribute on this guy, 
you need a total cycle time <25 s.  Aside from that stringent demand, 
it's an easy and rewarding target.  Make sure your absolute timekeeping 
is accurate!

V455 And.  Mainly timings of the 68/34 s pulsation.  Total cycle time 
<20 s needed.  Much more demanding than DQ Her... but better placed in 
the sky.

V1101 Aql.  Whenever it's faint (>14,7 or so).

Other targets.  ASASSN-14ei still refuses to die.  Gordon Myers, Bob 
Rea, and Josch Hambsch are gunning for it every night, and it continues 
to flash its lovely periodic (probably a superhump).  Let's keep the 
faith.  Those helium stars sure do love their echo outbursts!

Time to quit on V592 Cas.  Enrique has studied all the data coming in - 
quite a lot - and the star continues to flash a nice positive superhump 
and no other.  So we've learned all there is to learn, apparently, on 
this star, this year.

AH Men, AQ Men, IM Eri.  Time to start the season up for all these 
stars.  They have done yeoman service for us in the past, and we've 
published detections of negative superhumps in each (that is, *positive* 
detections of negative superhumps).  Now let's dig deeper: are the 
periodic signals always there? just how good are they in maintaining 
phase over long intervals?  AQ Men is also an eclipser, and I think the 
eclipse depths depend on precession phase - cute!  But the evidence from 
previous data is ambiguous - let's nail it down.  Note AH Men has a 
close companion of similar brightness; you might have to include it in 
the "aperture" - but however you decide to observe it, do it 
consistently. (Default, until someone tells me this is a bad idea, is to 
observe unfiltered and include the companion in the aperture.  I need 
help with this, though; it's hard to judge when you're a thousand miles 
from telescopes.)

BTW, northerners don't be bashful re IM Eri: a bright star at -20 
degrees, that's manageable.

And T Pyx - he's baaaacckk!  Time to start up the season.  The 
properties of the orbital signal get more fascinating with each passing 
month, it seems... if that's even possible.  New hypothesis: many CVs 
end their lives as a T Pyx, in a series of uncontrolled, repeated nova 
outbursts - evaporating the secondary in a million years.  We only see 
one in the sky (the biggest mystery of all: just one, and it's 4.5 kpc 
away!) because a million years is so short, just 0.01% of a CV's total 
lifetime.  We have to keep after this star.  Unfiltered, and keep the 
same comparison star.

FS Aurigae: start up the season!

WX Ari: Let's keep going, for sure.  And maybe you can go check on 
novalikes with orbital periods below 4.4 hours - are there any others in 
low states?  (Check Ritter catalog for the list.) We like these stars 
all the time, but *especially* when they're in low states.

joe

-------- Original Message --------
Return-Path: <atel at astronomerstelegram.org>


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The Astronomer's Telegram 
http://www.astronomerstelegram.org

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ATEL #6676							     ATEL #6676

Title:	ASAS-SN Discovery of a Very Bright Optical Transient
Author:	B. J. Shappee (Hubble Fellow, Carnegie Observatories), K.
		Z. Stanek, A. B. Davis, G. Simonian, T. W.-S. Holoien, C. S. Kochanek,
		U. Basu, J. F. Beacom (Ohio State), J. L. Prieto (Diego Portales;
		MAS), D. Bersier (LJMU), J. Brimacombe (Coral Towers Observatory),
		D. Szczygiel, G. Pojmanski (Warsaw University Observatory)
Queries:	shappee at astronomy.ohio-state.edu
Posted:	9 Nov 2014; 07:15 UT
Subjects:Optical, Cataclysmic Variable, Transient

During the ongoing All Sky Automated Survey for SuperNovae (ASAS-SN or
"Assassin"), using data from the quadruple 14-cm "Brutus" telescope in
Haleakala, Hawaii, we discovered a new transient source:

Object       RA (J2000)   DEC (J2000)      Disc. UT Date   Disc. V mag

ASASSN-14jv  18:53:28.87  +42:03:43.59     2014 Nov 9.19   11.3

ASASSN-14jv was present in two images obtained on 2014 Nov 9 but undetected
(V>15.7) on 2014-11-07.2 and earlier. There is a nearby blue source in
the Kepler Input Catalog (18:53:28.814, +42:03:43.57), with g=19.1, r=19.4,
and i=19.6, 0.6" away from our nominal position in the discovery image
(ASAS-SN image scale is 7.5"/pixel). Additionally, there is also a GALEX
source 0.021' away from our nominal position. ASASSN-14jv is most likely
a large-amplitude CV outburst, caught very early.

Follow-up observations are encouraged.

We thank LCOGT and its staff for their continued support of ASAS-SN. For
more information about the ASAS-SN project, see the <a 
href=http://www.astronomy.ohio-state.edu/~assassin/index.shtml>ASAS-SN
Homepage</a> and the list of all <a 
href=http://www.astronomy.ohio-state.edu/~assassin/transients.html>ASAS-SN
transients</a>.

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