MASTER: dwarf nova outbursts

ATel #8106; P. Balanuta, V. Shumkov, O. Gress, V. Vladimirov, V. Lipunov, E. Gorbovskoy, V. Kornilov, N. Tiurina, A. Kuznetsov, I. Gorbunov, D. Vlasenko, V. Chazov, E. Popova (M. V.Lomonosov MSU, SAI), A. Tlatov, V. Senik, D. Dormidontov (Kislovodsk Solar Station of the Pulkovo Observatory),N. Budnev, K. Ivanov (Irkutsk State University, Applied Physics Institute), D. Buckley, S. Potter, M. Kotze (South African Astronomical Observatory), R. Rebolo, M. Serra-Ricart, N. Lodieu, G. Israelian (The Instituto de Astrofisica de Canarias), V. Krushinskiy (Ural Federal University), Yu. Sergienko, A. Gabovich, V. Yurkov (Blagoveschensk Educational State University)
on 30 Sep 2015; 14:46 UT
Credential Certification: Nataly Tyurina (tiurina@sai.msu.ru)

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MASTER OT J061259.44+480703.0 discovery - new dwarf nova outburst (no VIZIER), Ampl>4.7m
MASTER-Kislovodsk auto-detection system ( Lipunov et al., Advances in Astronomy, MASTER Global Robotic Net, 2010 ) discovered OT source at (RA, Dec) = 06h 12m 59.44s +48d 07m 03.0s on 2015-09-29.02830 UT.
The OT unfiltered magnitude is 17.3m (limit 18.7m).
The OT is seen in 3 images. We have reference images without OT on 2011-11-04.98538 UT with unfiltered magnitude limit 20.6m and about 200 images during 2010-2015 in MASTER database. There is no minor planet at this place, no VIZIER source inside 10"(22m lim), so we can suggest the amplitude of this outburst is more then 4.7m

Spectral observations are required.

The discovery and reference images are available at: http://observ.pereplet.ru/images/MASTEROTJ061259.44480703.0.png

MASTER OT J202225.09+500457.4 discovery - bright possible dwarf nova outburst, Ampl>1.8m

MASTER-Kislovodsk auto-detection system discovered OT source at (RA, Dec) = 20h 22m 25.09s +50d 04m 57.4s on 2015-09-25.75610 UT.
The OT unfiltered magnitude is 15.5m (limit 18.5m).
The OT is seen in 4 images. There is no minor planet at this place. We have reference image without OT on 2010-09-15.71925 UT with unfiltered magnitude limit 19.5m. There is an USNO-B1 star in 0.8" with Bmag=17.2, R=17.4, J(2mass)=16.2, H=15.9, K=16.7, so we suggest the dwarf nova outburst with Ampl>1.8m
Spectral observations are required.
The discovery and reference images are available at http://observ.pereplet.ru/images/MASTEROTJ202225.09500457.4.png

Other transients

MASTER OT J034612.42-021839.2 detection
MASTER-IAC auto-detection system discovered OT source at (RA, Dec) = 03h 46m 12.42s -02d 18m 39.2s on 2015-09-26.15117 UT.
The OT unfiltered magnitude is 17.0m (limit 19.4m). The OT is seen in 2 images. There is no minor planet at this place.
The image and photometry are available at http://observ.pereplet.ru/images/MASTEROTJ034612.42-021839.2.png .
We have about 150 images with this OT from 2009 in MASTER-Kislovodsk database, but there is only WISE source in VIZIER database.
Spectral observations are required.

CRTS UGSU current outburst: RA= 16h 39m 42.73s +12d 24m 14.8s, 2015-09-27 21:16:51.251, unfiltered m=17.1
CRTS UG current outburst: 19h 55m 55.14s -30d 36m 01.3s, 2015-09-29 21:55:42.387, unfiltered m=16.8

MASTER Global Robotic Net