[vsnet-outburst 6955] Re: (cba:news) Possible New Object in Vulpecula at 19 59 00.225 +26 41 14.83

[arne]

Tom got "bit" by the most common error when observing unfiltered - finding
a red star.  While unfiltered observations work well for many astronomical
projects (period-finding of CVs, asteroid astrometry, discovering SNe),
going unfiltered has deficiencies for the majority of variable-star
research.  Beware of red stars!  Beware of large airmass!

Note that Tom could have protected
himself by looking at 2MASS to see if something IR-bright is at that
position.  Other checks are to look at the galactic longitude and
latitude, as most novae are close to the plane (ok in this case),
the minor planet checker, as Tom did, and VSX, the variable-star index
(available at http://www.aavso.org/vsx/ ) which lists all known
variable stars (much better than GCVS).

Such a red object could be a long period variable, or it could be
a reddened/embedded object; more study would be required.  When you
do find something you think is a real transient, you don't need to
send alerts to every maillist; vsnet-alert, baavss-alert and the main
aavso account cover almost everyone interested in these creatures.
A further post to Dan Green of the IAUC is worthwhile, but don't do that
step unless you are experienced; the other groups will confirm your result
and give you proper credit.

We once had a check-list of things to do before getting excited; I'll
see that it gets posted on our website, or highlighted if it already
exists.
Arne
--------
2MASS magnitudes:
   J              H               K
8.805 	0.029 	7.290 	0.016 	6.545 	0.018
------------------
Brian Skiff wrote:
 >      Looks as though it is a red variable with large J-K in 2MASS:
 >
 > GSC2 N033203195600 = USNO-B1.0 1166-0470058 = MSX6C G064.1479-01.5042
 >      = 2MASS J19590023+2641149 = IRAS 19569+2633
 >      19 59 00.23  +26 41 14.9  (J2000, 2MASS)
 >
 > ---  the match of the IRAS 12mu flux and MSX6C 'A' band flux makes
 >      the ID certain
 > ---  2MASS J-K = 2.3
 >
 >
 >
--------------------
Tom Krajci wrote:
> While doing photometry of HP Vul tonight I noticed a new star in my images
> approx 1 arcminute south of HP Vul.  Here are the results of an MP Checker:
> http://scully.harvard.edu/~cgi/MPCheck.COM
> 
> "No known minor planets, brighter than V = 20.0, were found in the
> 15.0-arcminute region around R.A. = 19 59 00, Decl. = +26 41 15 (J2000.0) on
> 2006 07 25.15 UT."
> 
> I've run astrometry using the UCAC2 catalog.  8 reference stars were used.
> Results:
> 
> Object name  hh mm ss.sss +dd mm ss.ss Mag (unfiltered CCD, using UCAC2
> photometry).
> HPVulNewObj1 19 59 00.225 +26 41 14.83 15.75
> Residual in RA:   000.483 [arcsec rms]
> Residual in DEC:  000.084 [arcsec rms]
> 
> A review of DSS1 and DSS2(red) plates show a faint star at these
> coordinates, but the DSS2(blue) plate does not show any star at this
> location.
> 
> Blinking images that span 45 minutes in time do not show any apparent motion
> of this object.
> 
> Time-series-photometry over 45 minutes shows a constant brightness.
> 
> I can provide FITS images or JPEG versions to those interested.
> 
> Request assistance in confirming this possible new object.
> 
> Thanks in advance!
> 
> Tom Krajci
> 
> PS.  My hunch is that it's a nova, because there appears to be a probable
> faint red progenitor that does not show on the DSS2(blue) plate...but I am
> unable to prove that.
>