October 2022 - vsnet-alert - ooruri.kusastro.kyoto-u.ac.jp

[vsnet-alert 26980] TCPJ23580961+5502508: appearance of ordinary superhumps
by Yusuke Tampo 13 Oct '22

13 Oct '22

TCPJ23580961+5502508: appearance of ordinary superhumps Sano-san's observations on 12th Oct. and Kyoto Univ. Obs's observations on 13th Oct. detected ordinary superhumps with an amplitude of ~0.1 mag and a period of 0.06123(4) d. Observers: Kyoto U. team, Itoh-san, Osaka Kyoiku U. team, Kiyota-san, Tamas Tordai, Sano-san, Josch Hambsch, Vihorlat Obs. Continuous observations are encouraged to determine its superhump evolutions Best, Yusuke

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[vsnet-alert 26979] ASASSN-15pd possible rare outburst
by Taichi Kato 12 Oct '22

12 Oct '22

ASASSN-15pd possible rare outburst YYYYMMDD(UT) mag observer 20221010.1440 15.279zr (ZTF Alert DC mag (Masci+ 2019)) 20221010.1729 15.258zg (ZTF Alert DC mag (Masci+ 2019))

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[vsnet-alert 26978] SDSS J001153.08-064739.1: superhump period
by Taichi Kato 12 Oct '22

12 Oct '22

SDSS J001153.08-064739.1: superhump period Josch Hambsch has reported further observations. The superhump period has been determined tp be 0.10414(3) d. Amplitude 0.20 mag. If these superhumps are of stage B, the expected q=0.165 (table 4 in arXiv:2201.02945 = VSOLJ Variable Star Bulletin No. 89). Even if they are of stage C, q would be 0.18. This is very much in disagreement with Rebassa-Mansergas et al. (2014) giving q=0.32(8).

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[vsnet-alert 26977] SDSS J001153.08-064739.1 superhumps
by Taichi Kato 11 Oct '22

11 Oct '22

SDSS J001153.08-064739.1 superhumps Josch Hambsch detected superhumps also on Oct. 10. Despite the brightness (still brighter than 14.0) and 0.2-mag superhumps, no one else appears to be observing. This object is in the period gap and has an unusual secondary. Please pay more attention.

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[vsnet-alert 26976] MASTER OT J001204.00-412337.4: 7th rebrightening
by Taichi Kato 11 Oct '22

11 Oct '22

MASTER OT J001204.00-412337.4: 7th rebrightening Josch Hambsch detected another rebrightening on Oct. 10 (16.2 mag). The object had been rising before this rebrightening.

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[vsnet-alert 26975] Optical observation of the afterglow of the extremely bright GRB 221009A (Swift J1913.1+1946) at iTelescope.Net T24
by Filipp Romanov 11 Oct '22

11 Oct '22

I observed the optical afterglow of the extremely bright GRB 221009A = Swift J1913.1+1946 remotely using telescope T24 (0.61-m f/6.5 reflector + CCD) of iTelescope.Net in Sierra Remote Observatory (Auberry, California, USA) on 2022-10-11. Two images (exposures 300 seconds, BINx1) were obtained with Ic filter, midtime of the stacked image is 06:12:42 UT (1d16h02m after the trigger). I clearly detected the afterglow and measured (aperture photometry, without deblending) following magnitude: 17.1 Ic +/- 0.2 from comparison to transformed (from Lupton 2005) magnitudes of nearby stars from the Pan-STARRS DR1 catalogue (Chambers et al., 2016). GRB221009A 20221010.2588 17.1I RFD 0.2 Magnitude was not corrected for the Galactic extinction. Stacked image available here: https://www.flickr.com/photos/filipp-romanov/52419866941

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[vsnet-alert 26974] Optical observations of the afterglow of the extremely bright GRB 221009A (Swift J1913.1+1946) from Burke-Gaffney Observatory
by Filipp Romanov 11 Oct '22

11 Oct '22

I observed the optical afterglow of the extremely bright GRB 221009A = Swift J1913.1+1946 (Dichiara et al., ATel #15650) remotely using 0.61-m f/6.5 Corrected Dall-Kirkham telescope of Burke-Gaffney Observatory (Lane, 2018, RTSRE, 1, 119) on 2022-10-10. Twelve images with exposures of 300 seconds and Iс filter were obtained, midtime of the first image is 02:06:45 UTC (11h56m after the trigger), midtime of the last image is 03:09:02 UTC (12h58m after the trigger). I clearly detected the afterglow and measured (aperture photometry, without deblending) following magnitudes of the afterglow from comparison to transformed (from Lupton 2005 formula) magnitudes of nearby stars from the Pan-STARRS DR1 catalogue (Chambers et al., 2016): Time (UTC)//Ic magnitude//Error GRB221009A 20221010.0880 15.54I RFD 0.12 GRB221009A 20221010.0919 15.60I RFD 0.10 GRB221009A 20221010.0958 15.54I RFD 0.11 GRB221009A 20221010.0996 15.60I RFD 0.11 GRB221009A 20221010.1035 15.64I RFD 0.12 GRB221009A 20221010.1074 15.59I RFD 0.11 GRB221009A 20221010.1119 15.67I RFD 0.11 GRB221009A 20221010.1158 15.69I RFD 0.10 GRB221009A 20221010.1197 15.69I RFD 0.11 GRB221009A 20221010.1235 15.64I RFD 0.12 GRB221009A 20221010.1274 15.70I RFD 0.13 GRB221009A 20221010.1313 15.92I RFD 0.13 Magnitudes were not corrected for Galactic extinction. FITS files available here: https://observatory.smu.ca/~bgo/sm/id.php?app=0&id=20769 and https://observatory.smu.ca/~bgo/sm/id.php?app=0&id=20770 Stacked image: https://observatory.smu.ca/~bgo/research/GRB_221009A.jpg

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[vsnet-alert 26973] Swift J1913.1+1946
by Taichi Kato 09 Oct '22

09 Oct '22

Swift J1913.1+1946 16.6-mag X-ray transient. ATEL #15650 ATEL #15650 Title: Swift J1913.1+1946 a new bright hard X-ray and optical transient Author: S. Dichiara (PSU), J. D. Gropp (PSU), J. A. Kennea (PSU), N. P. M. Kuin (UCL-MSSL), A. Y. Lien (U Tampa), F. E. Marshall (NASA/GSFC), A. Tohuvavohu (U Toronto) and M. A. Williams (PSU) report on behalf of the Neil Gehrels Swift Observatory Team Queries: jak51(a)psu.edu Posted: 9 Oct 2022; 14:44 UT Subjects:Optical, X-ray, Transient At 2022-10-09 14:10:17 UT, the Swift Burst Alert Telescope (BAT) triggered and located the new transient Swift J1913.1+1946 (triggers=1126853 and 1126854). Swift slewed immediately to the location. The BAT on-board calculated location is RA, Dec 288.263, +19.803 which is RA(J2000) = 19h 13m 03s Dec(J2000) = +19d 48' 09" with an uncertainty of 3 arcmin (radius, 90% containment, including systematic uncertainty). After slewing, the source was still visible (leading to the second trigger). The XRT began observing the field at 14:13:30 UT, 143 seconds after the BAT trigger. Using promptly downlinked data we find a bright, fading, uncatalogued X-ray source located at RA, Dec 288.2643, 19.7712 which is equivalent to: RA(J2000) = 19h 13m 3.43s Dec(J2000) = +19d 46' 16.3" with an uncertainty of 5.6 arcseconds (radius, 90% containment). This location is 1.9 arc minutes from the BAT onboard position, within the BAT error circle. UVOT took a finding chart exposure of 150 seconds with the White filter starting 179 seconds after the BAT trigger. There is a candidate counterpart in the rapidly available 2.7'x2.7' sub-image at RA(J2000) = 19:13:03.48 = 288.26452 DEC(J2000) = +19:46:24.6 = 19.77350 with a 90%-confidence error radius of about 0.61 arc sec. This position is 8.3 arc sec. from the center of the XRT error circle. The estimated magnitude is 16.63 with a 1-sigma error of about 0.14. No correction has been made for the large, but uncertain, extinction expected.

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[vsnet-alert 26972] ASASSN-21cw likely superoutburst
by Taichi Kato 09 Oct '22

09 Oct '22

ASASSN-21cw likely superoutburst YYYYMMDD(UT) mag observer 20220924.1525 14.835zr (ZTF Alert DC mag (Masci+ 2019)) 20220924.2318 15.133zg (ZTF Alert DC mag (Masci+ 2019)) 20220928.1463 15.229zr (ZTF Alert DC mag (Masci+ 2019)) 20220928.1503 15.574zg (ZTF Alert DC mag (Masci+ 2019)) 20220930.1538 15.691zg (ZTF Alert DC mag (Masci+ 2019)) 20220930.1721 15.321zr (ZTF Alert DC mag (Masci+ 2019)) 20221004.1749 15.537zr (ZTF Alert DC mag (Masci+ 2019)) 20221004.2403 16.130zg (ZTF Alert DC mag (Masci+ 2019)) 20221006.1620 16.504zg (ZTF Alert DC mag (Masci+ 2019)) 20221006.1850 15.700zr (ZTF Alert DC mag (Masci+ 2019))

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[vsnet-alert 26971] ASASSN-22mr: new WZ Sge-type dwarf nova
by Taichi Kato 09 Oct '22

09 Oct '22

ASASSN-22mr: new WZ Sge-type dwarf nova Berto Monard and Josch Hambsch have reported observations. The data show clear double-humped superhumps with a period of 0.0534(2) d (full amplitude 0.14 mag). 224117.532 -675916.24 (2000.0) Gaia_DR2_6385763697885620480 plx=3.080(0.730) dismod=7.6 pmra=7.201(1.050) pmdec=-1.210(1.120) G=20.444 BP=20.502 RP=20.160 224117.533 -675916.24 (2000.0) Gaia_EDR3_6385763697885620480 plx=2.711(0.552) dismod=7.8 pmra=6.612(0.477) pmdec=1.564(0.553) G=20.396 BP=20.299 RP=20.190 224117.459 -675916.64 (2000.0) GALEX_DR5_6384250644318917360 NUV=20.810(0.146) FUV=20.940(0.242)

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