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Merlin66
20-07-2013, 08:18 AM
J2000 Co-ordinates
RA 17h 50m 19.27s
Dec -33d 39m 07.3s
Mag (V) 12

This has recently be discovered and may be a cataclismic variable.
Are there any recent (and not so recent) images of this area???

Elio
20-07-2013, 08:33 AM
I got some shots in scorpio recently, is it near a well know object? :help:

Merlin66
20-07-2013, 08:52 AM
It's between the tail of Scorpius and Sagittarius.....
Plot the coordinates in CdC V3.8 - no bright star in the UCAC catalogue...

mithrandir
20-07-2013, 12:39 PM
The closest star I can find is UCAC4-282-131525. NOMAD has a different magnitude and nothing closer down to mag 24. Positions J2000.

17h50m18.58s -33°39'07.9" * UCAC4-282-131525 mV:15.28 b-v: 0.00 pmRA: -3 [mas/y] pmDE: -1 [mas/y] flags: 0
17h50m18.58s -33°39'07.9" * nmd 0563-0681266 mV:14.89 mB:15.50 mR:14.07 pmRA: -1 [mas/y] pmDE: -2 [mas/y] date: 1999.20 Jmag:12.956 Hmag:12.293 Kmag:12.065

The brightest things nearby:
17h50m21.25s -33°39'15.9" * UCAC4-282-131589 mV:13.01 b-v: 0.00 pmRA: 3 [mas/y] pmDE: 2 [mas/y] flags: 0

17h50m27.64s -33°40'00.3" * UCAC4-282-131721 mV:12.04 b-v: 0.00 pmRA: -6 [mas/y] pmDE: -8 [mas/y] flags: 0

and the winner:
17h50m52.83s -33°42'13.1" * SAO 209340 mV: 7.50 DM:CD-3312533 HD:1621020 GC:24216 sp:G5 pmRA: 2 [mas/y] pmDE: 26 [mas/y]

but SAO 209340 is about 8 arcmin away.

Rob_K
20-07-2013, 12:53 PM
This one was reported in ATel #5212 (18 July 2013) as Galactic Nova candidate VVV-NOV-003 by the VVV Survey. In ATel #5215 the OGLE team responded saying that this was the same as OGLE-2011-BLG-1444, announced in Sept 2011 as a candidate microlensing event. It was later suggested that this was a "nova-like" object (based on a spectrum obtained) but further observations by OGLE have indicated that this may be a symbiotic star (based on observed semi-regular periodicity in the pre-outburst stage and a long maximum). Not a classical nova in any case.
http://www.astronomerstelegram.org/?read=5212
http://www.astronomerstelegram.org/?read=5215

A light curve & discussion are here:
http://ogle.astrouw.edu.pl/cont/4_main/var/OGLE-2011-BLG-1444/index.html

I'll have to check my 'archive' to see if there's a trace of it. No doubt further spectra would be interesting Ken! ;)

Cheers -

Rob_K
20-07-2013, 05:32 PM
With V-I=1.5 this star in outburst bobbles around the noise level in my widefield shots but nonetheless I checked a few images and there appears to be a brightening in the correct position (obtained from DSS plate overlay with generated crosshairs) between October 2011 and March 2012. Definitely not the sort of thing I'd usually pick up in blinking images, especially with its slow steady rise to maximum.

I put together a very rough animation using 2 sets of images from those months, each cropped and resized to 2x actual pixel size. Hence VERY rough! :rolleyes: :P

Cheers -

Merlin66
20-07-2013, 05:49 PM
AAVSO Chart attached......

Elio
24-07-2013, 09:11 PM
I'll check my archive as soon as possible...thanks for info!

Terry B
24-07-2013, 10:22 PM
Here is an image and spectra from 21/7/13
Cheers

Terry

Rob_K
25-07-2013, 12:02 AM
Excellent Terry! :thumbsup: Can you tell anything from the spectrum as to its classification?

I had another look through my images and found one from May this year which went a bit deeper than I usually go. Unfortunately at the scale I shoot it's virtually overlaid on a mag 13.2 star - but nonetheless it's easy to see that something brighter than that is there. All shots pre-Sept 2011 show only an extremely faint response there. All shots after March 2012 show varying levels of a brighter response. Not checking between those dates as I don't have sufficient resolution to get anything meaningful on the brightening. :rolleyes:

http://i727.photobucket.com/albums/ww271/Rob_Kau/OGLE-2011-BLG-144408May201313-24UToverlay.jpg

Cheers -