TCP J05074264+2447555: the new transient (10.8 mag) in Taurus is a microlensing event

SPK
Affiliation
Association Française des Observateurs d'Étoiles Variables (AFOEV)
Tue, 10/31/2017 - 22:05

TCP J05074264+2447555

RA 05h07m42.64s, DEC +24°47'55.5" (J2000.0)

2017 Sept. 2.762 UT, 13.0 mag
2017 Oct. 25.688 UT, 11.7 mag
2017 Oct. 31.734 UT, 10.8 mag
(all CCD, unfiltered)

Discoverer: Tadashi Kojima, Gunma-ken, Japan

2017 10 31.734 UT
Discovered by T. Kojima, Gunma-ken, Japan, who found this on three frames taken using Canon EOS 6D + 135-mm f3.2 lens with the limiting mag.= 13.0. Star is visible on 2017 Sept. 2.762 (mag.= 13.0) and on Oct. 25.688 (mag.= 11.7) UT. Also this star is cataloged on USNO-A2 as mag.= B14.7 and R13.6. An image at
http://www.oaa.gr.jp/~oaacs/image/TCPinTau2017.jpg

Follow up-reports:
http://www.cbat.eps.harvard.edu/unconf/followups/J05074264+2447555.html

Clear skies,
Patrick

SPK
Affiliation
Association Française des Observateurs d'Étoiles Variables (AFOEV)
Microlensing event

Sebastian Otero's suggestion of a microlensing event is supported by Ulisse Munari's (INAF Padova) report: "Just taken a spectrum of the star at the provided coordinates. Nothing unusual, normal absorption stellar spectrum." (BAAVSS alert message)

Deconinck_M
Affiliation
American Association of Variable Star Observers (AAVSO)
Sketch and estimation

Thank you Patrick

As always you propose us an interresting observation to do.  And here an exotic one, I like it!

Tonight my best visual estimation despite the lunar presence was 12.4, between 12.0 and 12.6.

Here under a sketch of the field

Michel