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

[vsnet-alert 26678] TCP J05454551+5954307: early superhumps
by Taichi Kato 25 Mar '22

25 Mar '22

TCP J05454551+5954307: early superhumps Tamas Tordai, Itoh-san, Tonny Vanmunster, Stephen Brincat, Kiyota-san and Josch Hambsch have reported observations. This object has been now confirmed as a WZ Sge stars (confirming the earlier report). Double-wave early superhumps with a full amplitude of 0.10 mag and a period of 0.05631(3) d are present.

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[vsnet-alert 26677] TCP J05454551+5954307 = ASASSN-22dq
by Taichi Kato 23 Mar '22

23 Mar '22

TCP J05454551+5954307 = ASASSN-22dq > Tamas Tordai has reported observations. The data > show 0.08-mag early superhumps (double maxima) > with a period of 0.0561(8) d. I noticed that Tonny Vanmunster also reported observations under the first name. The first cycle of variation was not very regular according to Vanmunster's data. We should wait on more night to see if the variation is periodic.

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[vsnet-alert 26676] ASASSN-22dq: new WZ Sge-type dwarf nova
by Taichi Kato 23 Mar '22

23 Mar '22

ASASSN-22dq: new WZ Sge-type dwarf nova Tamas Tordai has reported observations. The data show 0.08-mag early superhumps (double maxima) with a period of 0.0561(8) d. ASASSN-22dq --- ------- 5:45:45.28 59:54:32.6 2022-03-19.29 13.65 SDSS DSS VIZIER ------- CV candidate, matches to PS1 g=20.0, g>16.7 on 2022-03-17.29, g=13.9 on 2022-03-19.29, g=14.6 on 2022-03-21.29 ASASSN-22dq 20220317.29 <167g ASN ASASSN-22dq 20220319.29 139g ASN ASASSN-22dq 20220321.29 146g ASN 054545.231 +595432.09 (2000.0) Gaia_DR2_282141555636377984 plx=2.781(0.664) dismod=7.8 pmra=0.263(0.611) pmdec=-2.593(0.740) G=19.746 BP=19.905 RP=19.273 054545.231 +595432.09 (2000.0) Gaia_EDR3_282141555636377984 plx=2.668(0.440) dismod=7.9 pmra=-0.451(0.272) pmdec=-2.094(0.321) G=19.707 BP=19.850 RP=19.333 No past outburst in the ZTF data.

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[vsnet-alert 26675] ASASSN-22dr
by Taichi Kato 23 Mar '22

23 Mar '22

ASASSN-22dr ASASSN-22dr --- ------- 10:54:17.35 -82:47:14.8 2022-03-20.13 12.89 SDSS DSS VIZIER ------- CV candidate, matches to GAIA DR2 G=20.8, g> 16.9 on 2022-03-18.17, g=15.9 on 2022-03-19.08, g=13.3 on 2022-03-20.12, g=13.6 on 2022-03-21.20 ASASSN-22dr 20220318.17 <169g ASN ASASSN-22dr 20220319.08 159g ASN ASASSN-22dr 20220320.12 133g ASN ASASSN-22dr 20220321.20 136g ASN 105419.470 -824717.58 (2000.0) Gaia_DR2_5197523925585449344 plx=3.619(1.273) dismod=7.2 pmra=-12.461(1.793) pmdec=6.315(2.095) G=20.655 BP=20.847 RP=19.181 105419.467 -824717.58 (2000.0) Gaia_EDR3_5197523925585449344 plx=2.479(0.946) dismod=8.0 pmra=-11.265(1.286) pmdec=6.210(1.473) G=20.585 BP=21.483 RP=19.301 105418.084 -824716.39 (2000.0) GALEX_DR5_6386748728292672066 NUV=22.218(0.444) FUV=-(-) No outburst in ASAS-3.

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[vsnet-alert 26674] Gaia22ayj: outburst from ultrashort period binary?
by Taichi Kato 23 Mar '22

23 Mar '22

Gaia22ayj: outburst from ultrashort period binary? ZTF data recorded time-resolved photometry on 2019 Jan. 10. The data show very clear double-wave modulations with a period of 0.006500(7) d. Using this period, I analyzed the entire ZTF data and found a period of 0.006499102(1) d = 9.4 min. The profile looks like that of a beta Lyr star with the primary and secondary eclipses of 1.5 and 0.7 mag. Although the period could be that of the spin period of the white dwarf, the amplitude is too large and the profile is too stable. The profile very much looks like an eclipsing binary and the period may be the orbital period. The period is, however, surprisingly short. The value is close to that of the direct impact AM CVn-type accretor V407 Vul (0.006590 d). Gaia22ayj showed an outburst (mag 16 in early March and may be still ongoing) and it suggests the presence of an accretion disk. Could it be a pre-AM CVn object? 082526.528 -223212.35 (2000.0) Gaia_DR2_5697000580270393088 plx=0.601(0.381) dismod=11.1 pmra=-4.255(0.538) pmdec=2.477(0.370) G=19.241 BP=19.399 RP=18.345 082526.528 -223212.34 (2000.0) Gaia_EDR3_5697000580270393088 plx=0.430(0.220) dismod=11.8 pmra=-4.238(0.206) pmdec=2.636(0.171) G=19.216 BP=19.570 RP=18.461

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[vsnet-alert 26673] ASASSN-22dl: eclipses
by Taichi Kato 20 Mar '22

20 Mar '22

ASASSN-22dl: eclipses Josch Hambsch and Itoh-san have reported new observations. The object already show eclipses at least since Mar. 18. It may have already entered a phase of ordinary superhumps (now stage A).

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[vsnet-alert 26672] ASASSN-15rs superoutburst
by Taichi Kato 18 Mar '22

18 Mar '22

ASASSN-15rs superoutburst YYYYMMDD(UT) mag observer 20220307.5176 <160c (Yutaka Maeda) 20220308.492 175C (Mitsutaka Hiraga) 20220308.5174 <163c (Yutaka Maeda) 20220309.5193 <153c (Yutaka Maeda) 20220310.5125 <145c (Yutaka Maeda) 20220312.4952 142:cG (Yutaka Maeda) 20220315.5073 <133c (Yutaka Maeda) 20220315.5319 146C (Masayuki Moriyama) 20220316.5009 143cG (Yutaka Maeda) 20220316.5009 143cG (Yutaka Maeda)

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[vsnet-alert 26671] MASTER OT J021216.01+461154.5 possible superoutburst
by Taichi Kato 18 Mar '22

18 Mar '22

MASTER OT J021216.01+461154.5 possible superoutburst Type from ZTF data. Supercycle about 800 d. YYYYMMDD(UT) mag observer 20220306.4731 <153c (Yutaka Maeda) 20220307.469 <174C (Mitsutaka Hiraga) 20220307.4768 <150c (Yutaka Maeda) 20220308.465 <174C (Mitsutaka Hiraga) 20220308.4765 <155c (Yutaka Maeda) 20220309.4784 <152c (Yutaka Maeda) 20220311.4562 <155c (Yutaka Maeda) 20220312.4537 <154c (Yutaka Maeda) 20220315.4640 139cG (Yutaka Maeda) 20220316.4602 138cG (Yutaka Maeda) 20220316.5197 140:C (Masayuki Moriyama)

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[vsnet-alert 26670] Re: ASASSN-22dl: new WZ Sge-type dwarf nova with large-amplitude early superhumps
by Taichi Kato 17 Mar '22

17 Mar '22

Re: ASASSN-22dl: new WZ Sge-type dwarf nova with large-amplitude early superhumps Using the ZTF data, I obtained Min(BJD) = 2458713.27415(12) + 0.05561039(3) d This is a deeply eclipsing WZ Sge-type object whose eclipse minima were below the detection limit of the ZTF observations. Orbital humps before the eclipses were also apparent, suggesting that the mass-transfer rate is not very low. The period of early superhumps (but still from a short baseline) is shorter than the orbital period by 0.13%, typical for a WZ Sge star. Tampo-san and Sebastian, please be careful about in drawing the conclusion. The ZTF data also have one-day aliases.

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[vsnet-alert 26669] Re: ASASSN-22dl: new WZ Sge-type dwarf nova with large-amplitude early superhumps
by Taichi Kato 17 Mar '22

17 Mar '22

Re: ASASSN-22dl: new WZ Sge-type dwarf nova with large-amplitude early superhumps I obtained a period of 0.0561(3) d from Kyoto U. data alone (very good data). The combined set with Itoh-san's data yielded a period of 0.05554(2) d. It looks like that the longer period is the true one.

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