TCP J06373299-0935420: new transient (10.4 mag) in Monoceros

Affiliation
Association Francaise des Observateurs d'Etoiles Variables (AFOEV)
Thu, 02/21/2019 - 16:51

TCP J06373299-0935420 (UG:)
https://www.aavso.org/vsx/index.php?view=detail.top&oid=684300

Discovery details:
R.A. 06h37m32.99s, Decl. -09°35'42.0" (J2000.0)
2019 Feb. 21.4516 UT, 10.4 mag (CCD, unfiltered)
Discoverer: Shizuo Kaneko (Kakegawa, Shizuoka-ken, Japan)

2019 02 21.452 UT
Discovered by S. Kaneko, Kakegawa, Shizuoka-ken, Japan, with on 10-s exposure on eight frames using Canon 6D digital camera + 200-mm f/2.8 lens under the limiting mag = 14.5, who writes that nothing is visible at this location on a frame taken on 2019 Feb. 20.447 UT with limit mag.= 14.7.

2019 02 21.65 UT
A (blue) progenitor candidate from Gaia DR2 is 0.3" away at R.A. 06h37m33.004s, Decl. -09°35'42.15" (equinox J2000.0, epoch 2015.5; Gmag. 19.21, parallax 2.7192 ± 0.4374 mas, distance ~0.38 kpc). Other designations are USNO-A2.0 0750-02439919 (Bmag. 18.6, Rmag. 18.9), USNO-B1.0 0804-0087491, GSC2.3 S3BJ014199 (Fmag. 18.9, Bjmag. 19.4), WISE J063733.02-093541.9, PSO J063733.002-093542.127 (gmag. 19.47, rmag. 19.32). Observations by the ASAS-SN Sky Patrol (Shappee et al. 2014ApJ...788...48S and Kochanek et al. 2017PASP..129j4502K) of the current brightening: 2019 Feb. 13.291 UT, gmag. fainter than 16.45; 21.156, gmag. 12.56; no previous eruptions or outbursts were recorded since 2012 Jan. 29; complete light curve at https://asas-sn.osu.edu/light_curves/aef18120-7c35-4b28-9a31-2e083608bf…
--- Patrick Schmeer (Saarbrücken-Bischmisheim, Germany)

http://www.cbat.eps.harvard.edu/unconf/followups/J06373299-0935420.html

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

Clear skies,
Patrick

Affiliation
American Association of Variable Star Observers (AAVSO)
New Transient Comps?

Glad to help!

   Do we have comps for the field? Best regards.

Mike

Affiliation
Association Francaise des Observateurs d'Etoiles Variables (AFOEV)
TCP J06373299-0935420 = ASASSN-19de

2019 02 21.78 UT

Meanwhile the All-Sky Automated Survey for Supernovae reported (on "Thu Feb 21 12:48:54 EST") this transient as ASASSN-19de: "RA 06:37:32.98, Dec -09:35:42.4, discovery 2019-02-21.15 UT, gmag. 12.16; bright CV candidate, matches to PS1 g=19.5, g>17.3 on 2019-02-13.29, g=12.6 on 2019-02-21.16."

http://www.astronomy.ohio-state.edu/~assassin/transients.html

Regards,
Patrick

Affiliation
American Association of Variable Star Observers (AAVSO)
Thanks, I observed this

Thanks, I observed this transient tonight, brillant and easy to observe. I post the estimations tomorrow. 

Michel

Affiliation
British Astronomical Association, Variable Star Section (BAA-VSS)
Also have observed

Taken a time resolved series this evening and uploaded to AID. Possibly some variation between Vmag 10.3 and 10.4 over ~70min. 

Affiliation
American Association of Variable Star Observers (AAVSO)
I made two estimations via

I made two estimations via Tycho magnitudes but there are quite were different, it looks like the magnitude change in 15 minutes from +/- 0.2 ???  My visual estimation was +10.4.

The stars given in the new sequence are too faint.

An interesting star indeed !

Michel 

Affiliation
American Association of Variable Star Observers (AAVSO)
Added Brighter Comps

Added Brighter Comps... should have done this yesterday... I apologize

 

 

Affiliation
American Association of Variable Star Observers (AAVSO)
Thank you Timothy, much

Thank you Timothy, much appreciated

Tonight visualy between 10.4 and 10.5 using your new sequence.

Michel

Affiliation
Association Francaise des Observateurs d'Etoiles Variables (AFOEV)
Probably a WZ Sge-type dwarf nova (at supermaximum)

Photometry and spectroscopy indicate that TCP J06373299-0935420 is a UGWZ superoutburst.

Affiliation
American Association of Variable Star Observers (AAVSO)
I wonder

Hello

Just as a question, I'm not specialised in spectroscopy but is it sure that this is a nova and not a SN ? There is a good galactical candidate in the neigbour, look at the photo taken by a friend (LLJA) and the references here join ?

Also, the curve decreasing is not a classical nova one, isn't it ?

Michel

Affiliation
American Association of Variable Star Observers (AAVSO)
How Long should I Monitor TCP J06373299-0935420?

Hello! I am happy to monitor TCP J06373299-0935420. How long is data typically useful after an outburst of this type? Thank you and best regards.

Mike

Affiliation
Vereniging Voor Sterrenkunde, Werkgroep Veranderlijke Sterren (Belgium) (VVS)
Coverage

Hi Mike,

in principle as long as you can observe the star. You need to adjust exposure times as the stars get dimmer. Superhumps may pop up at a larger amplitude only later in the outburst. Also there might be rebrightenings etc.

So I normally follow new targets as long as I can.

Josch

Affiliation
American Association of Variable Star Observers (AAVSO)
? Significant Drop in Brightness of TCP J06373299 over 24 Hours

Hello! My images from last night show a significant decrease in magnitude of TCP J06373299-0935420 of about 2 magnitudes from a day ago. I had windy conditions, and the magnitude is nearing the limits of my equipment, giving my measurements an error range about 0.2 mags in B,V, and I last night.

    Tonight, I will have better conditions, and I'll be able to use longer integration times to get a better error range. Best regards.

Mike

Affiliation
American Association of Variable Star Observers (AAVSO)
I confirm

I confirm

A friend of mine (LLJA) did this CCD estimation yesterday evening:

13.03.2019 - 20h30 UTC

     Filter Baader red magnitude 14.224

     Filter Baader bleue magnitude 14.875

For my 250mm it's off.  Maybe a hub in a while ...

Michel