Highly Reddened Variable Object discovered by MASTER
ATel #6029; V. Shumkov, D. Denisenko, V. Lipunov, E. Gorbovskoy, N. Tiurina, P. Balanutsa, V. Kornilov, N. Shatskiy, V. Chazov, A. Kuznetsov, V. Vladimirov, V. Yecheistov (Moscow State University, SAI), K. Ivanov, S. Yazev, N. Budnev, E. Konstantinov, O. Chuvalaev, V. Poleshchuk, O. Gress (Irkutsk State University), V. Yurkov, Y. Sergienko, D. Varda, E. Sinyakov, A. Gabovich (Blagoveshchensk Educational University), A. Parkhomenko, A. Tlatov, D. Dormidontov, V. Senik (Kislovodsk Solar Station of Pulkovo Observatory), V. Krushinsky, I. Zalozhnih, A. Popov, A. Bourdanov (Ural Federal University), P. Podvorotny, S. Shurpakov (MASTER team members), H. Levato, C. Saffe (ICATE), C. Mallamaci, C. Lopez, F. Podest (OAFA)
on 31 Mar 2014; 15:41 UT
Credential Certification: Nataly Tyurina (firstname.lastname@example.org)
Subjects: Infra-Red, Optical, Transient, Variables
MASTER OT J192123.07+193539.0 - extremely red large-amplitude variable
MASTER-Tunka auto-detection system discovered OT source at (RA, Dec) = 19h 21m 23.07s +19d 35m 39.0s on 2014-03-30.82148 UT. The OT unfiltered magnitude is 16.0m (limit 18.2m). The OT is seen in 7 images. There is no minor planet at this place. We have reference image without OT on 2013-04-04.86564 UT with unfiltered magnitude limit 18.9m.
The OT is identical to the star USNO-B1.0 1095-0381286 (19 21 22.947 +19 35 39.20 B2=19.92 R2=N/A I=17.48). It is showing a large variability on the digitized Palomar plates which results in unusual color on the BRIR finder chart uploaded to http://master.sai.msu.ru/static/OT/J192123+193539-BRIR5x5.jpg (2x zoom). The object has an infrared counterpart 2MASS 19212303+1935400 (J=14.78+/-0.03 H=12.29+/-0.02 K=9.96+/-0.02) with an extremely large color index (J-K) of 4.8. It was also detected in far infrared as IRAS 19191+1929 and WISE J192123.03+193539.9 (W1=6.74 W2=4.97 W3=3.52 W4=2.40). There is nothing at this position in 1RXS, GCVS and AAVSO VSX. This area of sky in Vulpecula is not covered by SDSS and CSS. Galactic coordinates are l=53.7, b=+2.5 and the extinction according to Schlafly et al., 2001 (ApJ 737:103) is AB=8.06, AJ=1.58, AK=0.67.
Judging from the large amplitude of variability and extremely red color, MASTER OT J192123.07+193539.0 can be a carbon star or a new variable of R CrB type. Follow up observations are required. The discovery and reference images are available at: http://master.sai.msu.ru/static/OT/192123.07193539.0.png
List of Optical Transients discovered by MASTER
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