[vsnet-outburst 22824] Re: TCP J08371988-0602457: new transient (13 mag) in Hydra

Tue Oct 23 07:09:51 JST 2018

Dear colleagues,

I have just concluded the analysis of my 2018, Oct 21/22 unfiltered CCD photometry session of TCP J08371988-0602457. Observations were made at CBA Extremadura Observatory over a short timespan of 1.1 hours,  using a 0.40-m f/5.1 telescope and SX-46 CCD camera, under clear skies. 

The resulting light curve does not show variations larger than 0.05 mag. 

Astrometry yields following coordinates (J2000.0): RA = 08h 37m 20.21s, Dec = -06° 02' 43.7" (+/- 0.2")

Observations will be sent to AAVSO, CBA and VSNET for further analysis. 

Best regards
Tonny

Tonny Vanmunster
CBA Belgium Observatory
CBA Extremadura Observatory
www.cbabelgium.com
www.peranso.com

-----Original Message-----
From: vsnet-outburst [mailto:vsnet-outburst-bounces at ooruri.kusastro.kyoto-u.ac.jp] On Behalf Of Patrick Schmeer pasc1312-aavso at yahoo.de via vsnet-outburst
Sent: zondag 21 oktober 2018 11:16
To: vsnet-alert at ooruri.kusastro.kyoto-u.ac.jp; vsnet-outburst at ooruri.kusastro.kyoto-u.ac.jp; cvnet-outburst at yahoogroups.com; baavss-alert at yahoogroups.com
Subject: [vsnet-outburst 22813] TCP J08371988-0602457: new transient (13 mag) in Hydra

TCP J08371988-0602457 = CSS_J083720.2-060242?  (UG:)

Discovery details:
R.A. 08h37m19.88s, Decl. -06°02'45.7" (J2000.0) Independent discoverers: Tadashi Kojima (Gunma-ken, Japan) and Shigehisa Fujikawa (Kan'onji, Kagawa, Japan)

2018 10 20.782 UT
Discovered by T. Kojima, Gunma-ken, Japan, on three frames with five second exposure using Canon EOS 6D digital camera
+ 200-mm f/3.2 lens under the limiting mag = 14.1, who
writes nothing is visible at this location on a frame taken on 2017 Nov. 28 UT with limit mag.= 13.5.

2018 10 20.7682 UT
Independently discovered by Shigehisa Fujikawa, Kan'onji, Kagawa, Japan, on a frame taken on 2018 Oct 20.7682 using a Minolta 120-mm-f.l. f/3.5 camera lens. His position end figures are 20s.13, 41".0 and his estimation of the magnitude is 12.3.

2018 10 21.13 UT
A possible progenitor is CSS_J083720.2-060242, magnitude range from Catalina Real-time Transient Survey (CRTS) data about 19.3–21.0. Gaia DR2 position end figures are 20.23s, 43.7" (J2000.0, Ep. 2000.0); proper motion pmRA= -17.8, pmDE= +10.8 mas/yr. Other designations are USNO-B1.0 0839-0186052, GSC2.3 S3LG001777, PSO J083720.218-060243.557.
No outbursts were recorded by the ASAS-SN Sky Patrol (Shappee et al. 2014ApJ...788...48S and Kochanek et al.
2017PASP..129j4502K) since 2012 Feb. 11; latest available observation is 2018 Oct. 17.592 UT, Vmag. 16.5 (contaminated by nearby stars); complete light curve at https://asas-sn.osu.edu/light_curves/e4b49b7b-6fc1-4eb1-a89d-88a43b35a83e
--- Patrick Schmeer (Saarbrücken-Bischmisheim, Germany)

http://www.cbat.eps.harvard.edu/unconf/followups/J08371988-0602457.html

*** Precise astrometry, time-resolved photometry, and spectroscopy are urgently required. ***

Clear skies,
Patrick