Multi-Band Photometry of a Bright Galactic Plane Transient ASASSN-17mt Supports the Nova Scenario
ATel #10785; S. Kiyota (Variable Star Observers League in Japan), K. Z. Stanek (OSU)
on 26 Sep 2017; 14:58 UT
Credential Certification: Krzysztof Stanek (stanek.32@osu.edu)
Multi-band follow-up photometry of Galactic nova candidate ASASSN-17mt
(Stanek et al. 2017, ATel #10772) obtained on UT 2017 Sep 25 18h33m by
S. Kiyota yields the following magnitude measurements: V=11.1, R=10.3,
I=9.6. Assuming an intrinsic color of (V-I)_0 ~ 0.0 as a
reasonable first guess for the intrinsic color of the nova candidate,
and using the above values of photometry, we arrive at an approximate
value of interstellar reddening of E(V-I)~1.5. That translates to
A_V~3.5, using the ratio of A_V/E(V-I)=2.5 from Stanek (1996). This is
consistent with the ``upper limit'' given by the total line-of-sight
extinction of A_V ~ 3.1 mag found using the NED Coordinate &
Extinction Calculator and the Schlafly et al. (2011) extinction
maps. Therefore, multi-band photometry reported here is consistent
with ASASN-17mt being a Galactic, moderately-obscured nova.
Follow-up observations, especially spectroscopy, are strongly encouraged.
