Photometric observations of the supernova 2009nr

We present the results of our UBVRI CCD photometry for the second brightest supernova of 2009, SN 2009nr, discovered during a sky survey with the telescopes of the MASTER robotic network. Its light and color curves and bolometric light curves have been constructed. The light-curve parameters and the maximum luminosity have been determined. SN 2009nr is shown to be similar in light-curve shape and maximum luminosity to SN 1991T, which is the prototype of the class of supernovae Ia with an enhanced luminosity. SN 2009nr exploded far from the center of the spiral galaxy UGC 8255 and most likely belongs to its old halo population. We hypothesize that this explosion is a consequence of the merger of white dwarfs

Prompt, early, and afterglow optical observations of five gamma-ray bursts (GRBs 100901A, 100902A, 100905A, 100906A, and 101020A)

We present results of the prompt, early, and afterglow optical observations of five gamma-ray bursts, GRBs 100901A, 100902A, 100905A, 100906A, and 101020A, made with the Mobile Astronomical System of TElescope-Robots in Russia (MASTER-II net), the 1.5-m telescope of Sierra-Nevada Observatory, and the 2.56-m Nordic Optical Telescope. For two sources, GRB 100901A and GRB 100906A, we detected optical counterparts and obtained light curves starting before cessation of gamma-ray emission, at 113 s and 48 s after the trigger, respectively. Observations of GRB 100906A were conducted with two polarizing filters. Observations of the other three bursts gave the upper limits on the optical flux; their properties are briefly discussed. More detailed analysis of GRB 100901A and GRB 100906A supplemented by Swift data provides the following results and indicates different origins of the prompt optical radiation in the two bursts. The light curves patterns and spectral distributions suggest a common production site of the prompt optical and high-energy emission in GRB 100901A. Results of spectral fits for GRB 100901A in the range from the optical to X-rays favor power-law energy distributions with similar values of the optical extinction in the host galaxy. GRB 100906A produced a smoothly peaking optical light curve suggesting that the prompt optical radiation in this GRB originated in a front shock. This is supported by a spectral analysis. We have found that the Amati and Ghirlanda relations are satisfied for GRB 100906A. An upper limit on the value of the optical extinction on the host of GRB 100906A is obtained.Comment: 18 pages, 14 figures, 14 tables, 5 machine readable tables; accepted for publication in MNRA

Observation of Multi-Gap Superconductivity in GdO(F)FeAs by Andreev Spectroscopy

We have studied current-voltage characteristics of Andreev contacts in polycrystalline GdO$_{0.88}$F$_{0.12}$FeAs samples with bulk critical temperature ${T_c}$ = (52.5 \pm 1)K using break-junction technique. The data obtained cannot be described within the single-gap approach and suggests the existence of a multi-gap superconductivity in this compound. The large and small superconducting gap values estimated at T = 4.2K are {\Delta}L = 10.5 \pm 2 meV and {\Delta}S = 2.3 \pm 0.4 meV, respectively.Comment: 5 pages, 4 figures, submitted to JETP Letter

The MASTER-II network of robotic optical telescopes. First results

The main stages in the creation of the Russian segment of the MASTER network of robotic telescopes is described. This network is designed for studies of the prompt optical emission of gammaray bursts (GRBs; optical emission synchronous with the gamma-ray radiation) and surveys of the sky aimed at discovering uncataloged objects and photometric studies for various programs. The first results obtained by the network, during its construction and immediately after its completion in December 2010, are presented. Eighty-nine alert pointings at GRBs (in most cases, being the first ground telescopes to point at the GRBs) were made from September 2006 through July 2011. The MASTER network holds first place in the world in terms of the total number of first pointings, and currently more than half of first pointings at GRBs by ground telescopes are made by the MASTER network. Photometric light curves of GRB 091020, GRB 091127, GRB 100901A, GRB 100906A, GRB 10925A, GRB 110106A, GRB 110422A, and GRB 110530A are presented. It is especially important that prompt emission was observed for GRB 100901A and GRB 100906A, and thar GRB 091127, GRB 110422A, and GRB 110106A were observed from the first seconds in two polarizations. Very-wide-field cameras carried out synchronous observations of the prompt emission of GRB 081102, GRB 081130B, GRB 090305B, GRB 090320B, GRB 090328, and GRB 090424. Discoveries of Type Ia supernovae are ongoing (among them the brightest supernova in 2009): 2008gy, 2009nr, 2010V, and others. In all, photometry of 387 supernovae has been carried out, 43 of which were either discovered or first observed with MASTER telescopes; more than half of these are Type Ia supernovae. Photometric studies of the open clusters NGC 7129 and NGC 7142 have been conducted, leading to the discovery of 38 variable stars. Sixty-nine optical transients have been discovered. © 2013 Pleiades Publishing, Ltd

First gravitational-wave burst GW150914: MASTER optical follow-up observations

The Advanced LIGO observatory recently reported the first direct detection of the gravitational waves (GWs) predicted by Einstein & Sitzungsber. We report on the first optical observations of the GW source GW150914 error region with the Global MASTER Robotic Net. Between the optical telescopes of electromagnetic support, the covered area is dominated by MASTER with an unfiltered magnitude up to 19.9 mag (5σ). We detected several optical transients, which proved to be unconnected with the GW event. The main input to investigate the final error box of GW150914 was made by the MASTER-SAAO robotic telescope, which covered 70 per cent of the final GW error box and 90 per cent of the common localization area of the LIGO and Fermi events. Our result is consistent with the conclusion (Abbott et al. 2016a) that GWs from GW150914 were produced in a binary black hole merger. At the same time, we cannot exclude that MASTER OT J040938.68-541316.9 exploded on 2015 September 14.Fil: Lipunov, V. M.. Lomonosov Moscow State University; RusiaFil: Kornilov, V.. Lomonosov Moscow State University; RusiaFil: Gorbovskoy, E.. Lomonosov Moscow State University; RusiaFil: Buckley, D. A. H.. South African Astronomical Observatory; SudáfricaFil: Tiurina, N.. Lomonosov Moscow State University; RusiaFil: Balanutsa, P.. Lomonosov Moscow State University; RusiaFil: Kuznetsov, A.. Lomonosov Moscow State University; RusiaFil: Greiner, J.. Max-Planck-Institut für extraterrestrische Physik; AlemaniaFil: Vladimirov, V.. Lomonosov Moscow State University; RusiaFil: Vlasenko, D.. Lomonosov Moscow State University; RusiaFil: Chazov, V.. Lomonosov Moscow State University; RusiaFil: Kuvshinov, D.. Lomonosov Moscow State University; RusiaFil: Gabovich, A.. Blagoveschensk State Pedagogical University; RusiaFil: Potter, S. B.. South African Astronomical Observatory; SudáfricaFil: Kniazev, A.. South African Astronomical Observatory; SudáfricaFil: Crawford, S.. South African Astronomical Observatory;Fil: Rebolo Lopez, R.. Instituto de Astrofacuteisica de Canarias Vía Láctea; EspañaFil: Serra Ricart, M.. Instituto de Astrofacuteisica de Canarias Vía Láctea; EspañaFil: Israelian, G.. Instituto de Astrofacuteisica de Canarias Vía Láctea; EspañaFil: Lodieu, N.. Instituto de Astrofacuteisica de Canarias Vía Láctea; EspañaFil: Gress, O.. Irkutsk State University; RusiaFil: Budnev, N.. Irkutsk State University; RusiaFil: Ivanov, K.. Irkutsk State University; RusiaFil: Poleschuk, V.. Irkutsk State University; RusiaFil: Yazev, S.. Irkutsk State University; RusiaFil: Tlatov, A.. Russian Academy of Sciences. Pulkovo Astronomical Observatory; RusiaFil: Senik, V.. Russian Academy of Sciences. Pulkovo Astronomical Observatory; RusiaFil: Yurkov, V.. Blagoveschensk State Pedagogical University; RusiaFil: Dormidontov, D.. Russian Academy of Sciences. Pulkovo Astronomical Observatory; RusiaFil: Parkhomenko, A.. Russian Academy of Sciences. Pulkovo Astronomical Observatory; RusiaFil: Sergienko, Yu.. Blagoveschensk State Pedagogical University; RusiaFil: Podestá, Ricardo César. Universidad Nacional de San Juan. Facultad de Ciencias Exactas Físicas y Naturales. Departamento de Informática. Observatorio Astronómico Félix Aguilar; ArgentinaFil: Levato, Orlando Hugo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - San Juan. Instituto de Ciencias Astronómicas, de la Tierra y del Espacio. Universidad Nacional de San Juan. Instituto de Ciencias Astronómicas, de la Tierra y del Espacio; ArgentinaFil: López, Carlos Eduardo. Universidad Nacional de San Juan. Facultad de Ciencias Exactas Físicas y Naturales. Departamento de Informática. Observatorio Astronómico Félix Aguilar; ArgentinaFil: Saffe, Carlos. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - San Juan. Instituto de Ciencias Astronómicas, de la Tierra y del Espacio. Universidad Nacional de San Juan. Instituto de Ciencias Astronómicas, de la Tierra y del Espacio; ArgentinaFil: Podestá, Florencia. Universidad Nacional de San Juan. Facultad de Ciencias Exactas Físicas y Naturales. Departamento de Informática. Observatorio Astronómico Félix Aguilar; ArgentinaFil: Mallamaci, Claudio Carlos. Universidad Nacional de San Juan. Facultad de Ciencias Exactas Físicas y Naturales. Departamento de Informática. Observatorio Astronómico Félix Aguilar; Argentin

Early polarization observations of the optical emission of gamma-ray bursts: GRB 150301B and GRB 150413A

We report early optical linear polarization observations of two gamma-ray burstsmade with the MASTER robotic telescope network. We found the minimum polarization for GRB 150301B to be 8 per cent at the beginning of the initial stage, whereas we detected no polarization for GRB 150413A either at the rising branch or after the burst reached the power-law afterglow stage. This is the earliest measurement of the polarization (in cosmological rest frame) of gamma-ray bursts. The primary intent of the paper is to discover optical emission and publish extremely rare (unique) high-quality light curves of the prompt optical emission of gammaray bursts during the non-monotonic stage of their evolution. We report that our team has discovered the optical counterpart of one of the bursts, GRB 150413A.Fil: Gorbovskoy, E.S.. Lomonosov Moscow State University; Rusia. Moscow State University; RusiaFil: Lipunov, V.M.. Lomonosov Moscow State University; . Moscow State University; RusiaFil: Buckley, D. A. H.. South African Astronomical Observatory; SudáfricaFil: Kornilov, V. G.. Lomonosov Moscow State University; Rusia. Moscow State University; RusiaFil: Balanutsa, P. V.. Lomonosov Moscow State University; Rusia. Moscow State University; RusiaFil: Tyurina, N. V.. Lomonosov Moscow State University; Rusia. Moscow State University; RusiaFil: Kuznetsov, A. S.. Lomonosov Moscow State University; Rusia. Moscow State University; RusiaFil: Kuvshinov, D. A.. Lomonosov Moscow State University; Rusia. Moscow State University; RusiaFil: Gorbunov, I. A.. Lomonosov Moscow State University ; Rusia. Sternberg Astronomical Institute, Moscow State University; RusiaFil: Vlasenko, D.. Lomonosov Moscow State University; RusiaFil: Popova, E.. Lomonosov Moscow State University; Ruanda. Sternberg Astronomical Institute; RusiaFil: Chazov, V. V.. Sternberg Astronomical Institute; Rusia. Lomonosov Moscow State University; RusiaFil: Potter, S.. South African Astronomical Observatory; SudáfricaFil: Kotze, M.. South African Astronomical Observatory; SudáfricaFil: Kniazev, A. Y.. South African Astronomical Observatory; Sudáfrica. Southern African Large Telescope Foundation; SudáfricaFil: Gress, O. A.. Irkutsk State University; RusiaFil: Budnev, N. M.. Irkutsk State University; RusiaFil: Ivanov, K. I.. Irkutsk State University; RusiaFil: Yazev, S. A.. Irkutsk State University; RusiaFil: Tlatov, A. G.. Kislovodsk Solar Station of the Pulkovo Observatory RAS; RusiaFil: Senik, V. A.. Lomonosov Moscow State University; Rusia. Sternberg Astronomical Institute; Rusia. Kislovodsk Solar Station of the Pulkovo Observatory RAS; RusiaFil: Dormidontov, D. V.. Lomonosov Moscow State University; Rusia. Sternberg Astronomical Institute; Rusia. Kislovodsk Solar Station of the Pulkovo Observatory RAS; RusiaFil: Parhomenko, A. V.. Lomonosov Moscow State University; . Pulkovo Observatory Of The Russian Academy Of Sciences; . Sternberg Astronomical Institute; RusiaFil: Krushinski, V. V.. Kislovodsk Solar Station of the Pulkovo Observatory RAS; RusiaFil: Zalozhnich, I. S.. Kislovodsk Solar Station of the Pulkovo Observatory RAS; RusiaFil: Castro Tirado, R. Alberto. Consejo Superior de Investigaciones Científicas; EspañaFil: Sánchez Ramírez, R.. Consejo Superior de Investigaciones Científicas; EspañaFil: Sergienko, Yu.P.. Blagoveschensk Educational State University; RusiaFil: Gabovich, A.. Blagoveschensk Educational State University; RusiaFil: Yurkov, V.V.. Blagoveschensk Educational State University; RusiaFil: Levato, Orlando Hugo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - San Juan. Instituto de Ciencias Astronómicas, de la Tierra y del Espacio. Universidad Nacional de San Juan. Instituto de Ciencias Astronómicas, de la Tierra y del Espacio; ArgentinaFil: Saffe, Carlos. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - San Juan. Instituto de Ciencias Astronómicas, de la Tierra y del Espacio. Universidad Nacional de San Juan. Instituto de Ciencias Astronómicas, de la Tierra y del Espacio; ArgentinaFil: Mallamaci, Claudio Carlos. Observatorio Astronmico Félix Aguilar; ArgentinaFil: Lopez, C.. Universidad Nacional de San Juan. Facultad de Ciencias Exactas Físicas y Naturales. Departamento de Informática. Observatorio Astronómico Félix Aguilar; ArgentinaFil: Podesta, F.. Universidad Nacional de San Juan. Facultad de Ciencias Exactas Físicas y Naturales. Departamento de Informática. Observatorio Astronómico Félix Aguilar; ArgentinaFil: Vladimirov, V. V.. Lomonosov Moscow State University; Rusia. Sternberg Astronomical Institute, Moscow State University; Rusi