[Aavso-photometry] new transient: CSS080623:142206+334546 14:22:05.77 +33:45:46.1

[Tim Crawford]

Brian,

You are right about which star Arne Was referring to: 14 22 04.05  +33 48 17.8 as the suggested comp.... A bit of sleep deprivation had my finger stopping ~ 1.5 arc sec North instead of ~ 3.0 arc sec North.  Thanks for the Catch.

The one that I was attempting to use is at: 14 22 02.74 +33 46 30.61

OK, I just ran an SDSS search on this FOV and the  comp Arne Suggested at 14 22 04.05 +33 48 17.77 computes V = 14.857 while the comp at 14 22 02.74 +33 46 30.61 computes V = 17.466

You are right, the FOV is rich with SDSS photometry as a query returned some 17 stars with BVRI photometry within 6 arc min.

Kerri at HQ has already added this target to the Validation file: 000-BFT-464   aka CSS080623:142206+334546

Last nights observation:

17.799  .048  UT 2008/07/09/07/14/20

This may be a worth while object to follow for a bit in as much as Arne's July 8th email showed this to have two previous obs of:

18.6 on June 25 and 18.15 on July 2

Getting Brighter for sure.

Target Coordinates:  14 22 05.77 +33 45 46.1

ad Astra

Tim Crawford, CTX
Arch Cape Observatory



----- Original Message ----
From: Brian Skiff <bas at lowell.edu>
To: tcarchcape at yahoo.com
Cc: aavso-discussion at mira.aavso.org
Sent: Wednesday, July 9, 2008 11:27:27 AM
Subject: Re: [AAVSO-DIS] new transient: CSS080623:142206+334546 14:22:05.77 +33:45:46.1

     Arne suggested:

>>  I'd use 
>>  the star about 3 arcmin due north of the target as your
>>  comparison star, just so that everyone is on the same
>>  system.


     I'm pretty Arne's intended star is this one:

UCAC2 43623889:  14 22 04.05 +33 48 17.8  (J2000)

...for which SDSS shows r' = 14.69, matching also Carlsberg 14 r'
from prior observations.  A rough adjustment yields Rc = 14.4
and V = 14.9 for this star.

     I couldn't find Tim Crawford's star, but another fainter one
nearby the first one is:

GSC2.3 N698003902 = SDSS J142206.62+334743.5 (among other aliases):
                  14 22 06.63 +33 47 43.6  (J2000, SDSS)

Sloan r' = 17.28, and g'-r' = 0.46, yielding about Rc = 17.05 and
V = 17.6.


     ...perhaps the main point is that there's plenty of reliable
SDSS photometry in the field, so selected comp stars could be
found and Johnson-Cousins magnitudes/colors found from the
published transformations (more rigorously than what's shown above).



\Brian