[vsnet-alert 14712] (fwd) nova candidate discovery - India

Taichi Kato tkato at kusastro.kyoto-u.ac.jp
Thu Jun 28 09:08:37 JST 2012


Date: Wed, 27 Jun 2012 11:40:44 +0530
Subject: Probable nova candidate discovery - India
From: Amar Sharma <amar10sharma at gmail.com>

Hello VSNET admins,

Greetings from India!

I was attempting imaging Pluto on 2 recent nights (19-06 & 21-06) with our
Nikaya Observatory's C-14 Edge HD and SBIG ST-8XME, and saw a bright star
which appeared to be visually at 11-12th mag star on the CCD image. I went
to DSS and initially believed it to be Pluto since the star was not there
on DSS images (my first time imaging Pluto). But on further inspection I
confirmed Pluto just 1 arc minute away. I do confirm presence of a bright
star in my image which appears to have flared up which is not there in 2 of
the different DSS images. I have elaborated the following in images in my
album.

https://picasaweb.google.com/100263423283309558687/June23201202#

Here are the exact coordinates of the most likely nova candidate.

RA: 18h 35m 10.54s and DEC: -19=B0 19' 30"
Constellation: Sagittarius. Proximity of open star cluster M25.
Estimated magnitude (unfiltered) with Photometry tool from Maxim DL =3D App=
.
11.5 mag
Image was taken un-filtered.

I checked with DSS and there is no star anywhere brighter than ~16-17th mag
at that position. I have also checked again with the AAVSO finder charts,
and there is nothing existing in the estimated position. I have cross
checked with GCVS too.

The candidate star I have is convincingly much brighter than anything
existing earlier there. While attempting to image Pluto which was in the
field, I have it on 2 CCD images taken first on 19-06 then on 21-06. I also
have registered it on 23-06.

Hence I reported it to IAU's CBAT on Saturday 23rd June at 10:30 UT with
subsequent follow up emails announcing it as a probable new nova candidate
discovery. However its very concerning to me that I have not heard even one
word from CBAT since then; I have been waiting for 3 days. I believe in all
probability this is a new object!

Interestingly SIMBAD lists a 17 Mag IR (infrared) source at the same
location as my suspect. Its called IRAS 18322-1921.

http://simbad.u-strasbg.fr/simbad/sim-id?NbIdent=3D1&Ident=3DIRAS%2018322-1=
921

Further to this I requested Dr. Alan Hale (of Comet Hale-Bopp fame). As a
very experienced visual observer he got back to me on June 26.29 UT,
estimating its visual magnitude as 13.5. It clearly has faded little since
the time I observed it first 7 night back.

I would request your expert team to look into this probable candidate. Some
of the scientists in my city were able to point two 2-metre telescopes at
the target. From one of their inferences it appears to be a late M type
flared star.

I have approached you very late since the object has begun fading now. I
didnt see anything on your Recent Notices too about this object. However I
hope to hear something interesting from you.

*****************************

Here are some of my personal details:

1) OBSERVER NAME: Amar A. Sharma

2) LOCATION: Nikaya Observatory (private observatory)
60km from Bangalore, India
Latitude: +12* 36'
Longitude: 77E 43'
App height: 850 meters above sea level

4) DATE AND UT TIME OF OBSERVATION:

2012-06-19 T 20:12:44.000
2012-06-21 T 19:06:50.000

5) DETAILS ON INSTRUMENTATION

Celestron 14" Edge HD on CGE Pro mount
SBIG ST-8XME CCD
Working with a focal reducer at f/6.9
Effective focal length is 2418 mm
No filters

Thanks, Amar A. Sharma, India.


More information about the vsnet-alert mailing list