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

[vsnet-alert 28062] ZTF18acynctq = TCP J20402089+4915562 = ASASSN-25bt: new SU UMa star candidate
by Yusuke Tampo 20 May '25

20 May '25

ZTF18acynctq = TCP J20402089+4915562 = ASASSN-25bt: new SU UMa star candidate XOSS team via TOCP/TNS and ASAS-SN reported the 2025 outburst of this system, which is already known as ZTF18acynctq in its 2018 outburst. https://alerce.online/object/ZTF18acynctq http://www.cbat.eps.harvard.edu/unconf/followups/J20402089+4915562.html https://www.aavso.org/vsx/index.php?view=detail.top&oid=10848612 Its 2018 outburst lasted for ~15 days and showed a possible rebrightening in the ATLAS data. Thus the outburst cycle is ~2300 d. This system is currently ~16.0 mag, and time-resolved observations may detect superhumps. Best regards, Yusuke -- ---------------------------------------------- South African Astronomical Observatory, Postdoc fellow 反保雄介 Yusuke TAMPO MAIL: tampo(a)kusastro.kyoto-u.ac.jp MAIL: yusuke(a)saao.ac.za ----------------------------------------------

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[vsnet-alert 28061] V598 Sco: an eclipsing dwarf nova
by Rod Stubbings 19 May '25

19 May '25

V598 Sco is an active dwarf nova and listed in VSX as a UG star, range 14.9 - 17.0: V. [vsnet-chat 9283] lists V598 Sco as a Z Cam star. V598 Sco has been on my list for a number of years. On May 2 during an outburst I noticed a fading, then returned to normal brightness. A second fading occurred approx 3h 46 min later, which I observed back to normal. With a new outburst on May 18, I made 1-minute observations for 3h 29 minutes and caught another eclipse. Kept observations ongoing throughout the night and caught a second eclipse. The eclipse period was 3h 45 minutes. The first eclipse duration was 12 minutes and the second eclipse was 10 minutes. First eclipse: V598 SCO 2460814.0236 15.20 V598 SCO 2460814.0243 15.10 V598 SCO 2460814.0250 15.10 V598 SCO 2460814.0257 15.20 V598 SCO 2460814.0264 15.20 V598 SCO 2460814.0271 15.20 V598 SCO 2460814.0278 15.20 V598 SCO 2460814.0285 15.20 V598 SCO 2460814.0292 15.20 V598 SCO 2460814.0299 15.30 V598 SCO 2460814.0306 15.30 V598 SCO 2460814.0313 -15.30 V598 SCO 2460814.0319 -15.30 V598 SCO 2460814.0326 -15.40 V598 SCO 2460814.0333 -15.40 V598 SCO 2460814.0340 -15.40 V598 SCO 2460814.0347 -15.40 V598 SCO 2460814.0354 -15.50 V598 SCO 2460814.0361 -15.50 V598 SCO 2460814.0368 -15.50 V598 SCO 2460814.0375 -15.50 V598 SCO 2460814.0382 -15.50 V598 SCO 2460814.0389 -15.50 V598 SCO 2460814.0396 15.60 V598 SCO 2460814.0403 15.60 V598 SCO 2460814.0410 15.40 V598 SCO 2460814.0417 15.40 V598 SCO 2460814.0424 15.30 V598 SCO 2460814.0431 15.30 V598 SCO 2460814.0438 15.20 V598 SCO 2460814.0444 15.20 V598 SCO 2460814.0451 15.10 V598 SCO 2460814.0458 15.10 Second eclipse: V598 SCO 2460814.1833 14.90 V598 SCO 2460814.1840 15.00 V598 SCO 2460814.1847 15.10 V598 SCO 2460814.1854 15.10 V598 SCO 2460814.1861 15.10 V598 SCO 2460814.1868 15.20 V598 SCO 2460814.1875 15.30 V598 SCO 2460814.1882 -15.30 V598 SCO 2460814.1889 -15.30 V598 SCO 2460814.1896 -15.30 V598 SCO 2460814.1903 -15.30 V598 SCO 2460814.1910 -15.30 V598 SCO 2460814.1917 -15.40 V598 SCO 2460814.1924 -15.40 V598 SCO 2460814.1931 -15.40 V598 SCO 2460814.1938 -15.40 V598 SCO 2460814.1944 -15.40 V598 SCO 2460814.1951 15.50 V598 SCO 2460814.1958 15.50 V598 SCO 2460814.1965 15.40 V598 SCO 2460814.1972 15.40 V598 SCO 2460814.1979 15.30 V598 SCO 2460814.1986 15.30 V598 SCO 2460814.1993 15.10 V598 SCO 2460814.2000 15.00 V598 SCO 2460814.2007 15.00 V598 SCO 2460814.2014 14.90 V598 SCO 2460814.2021 14.90 V598 SCO 2460814.2028 14.90 -- Rod Stubbings Tetoora Road Observatory Victoria, Australia Honorary Associate member Astronomical Society of Australia Telescope: "Infinity" 22" f/3.8 stubbo(a)dcsi.net.au http://rodstubbingsobservatory.wordpress.com/

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[vsnet-alert 28060] TCP J19065629+4019093: new SU UMa-type dwarf novae and WZ Sge-type candidate
by Yusuke Tampo 11 May '25

11 May '25

TCP J19065629+4019093: new SU UMa-type dwarf novae and WZ Sge-type candidate TCP J19065629+4019093 was discovered by Y. Nakamura on 29th April, 2025, at 13.1 mag. S. M. Brincat, J. Hambsch, Itoh-san, T. Tordai, and Sano-san have reported the time-resolved observations of this new transient. The latest time-resolved observations on 9th May by S. M. Brincat report the presence of single-peaked superhumps with ~0.056 d. Thus TCP J19065629+4019093 is a new SU UMa-type dwarf nova. Taking into account this late (~10 d) appearance of superhumps, TCP J19065629+4019093 is likely a face-on WZ Sge-type dwarf nova. Further observations are encouraged to determine its superhump period. Best regards, Yusuke -- ---------------------------------------------- South African Astronomical Observatory, Postdoc fellow 反保雄介 Yusuke TAMPO MAIL: tampo(a)kusastro.kyoto-u.ac.jp MAIL: yusuke(a)saao.ac.za ----------------------------------------------

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[vsnet-alert 28059] TCP J13560585+3727068: new WZ Sge-type dwarf nova
by Yusuke Tampo 30 Apr '25

30 Apr '25

TCP J13560585+3727068: new WZ Sge-type dwarf nova TCP J13560585+3727068 was discovered on 2025 04 26.7039 (UTC) at 14.3 mag (unfiltered). GIven the possible counterpart of Gaia G~20.8 and peak in ASAS-SN around 13.5 mag on 2025 04 24, the outburst amplitude is ~7.3 mag Itoh-san reported the time-resolved observations of TCP J13560585+3727068 on 2024 04 28 and 29. The light curve shows double-peaked modulations with the tentative period is 0.0574(1) d (aliases are possible) with ~0.04-mag amplitude. Thus, TCP J13560585+3727068 is likely a new WZ Sge-type dwarf nova. http://www.cbat.eps.harvard.edu/unconf/followups/J13560585+3727068.html https://asas-sn.osu.edu/sky-patrol/coordinate/19dd78d4-1819-43b4-bb38-be83e… Time-resolved observations are encouraged. Best regards, Yusuke -- ---------------------------------------------- South African Astronomical Observatory, Postdoc fellow 反保雄介 Yusuke TAMPO MAIL: tampo(a)kusastro.kyoto-u.ac.jp MAIL: yusuke(a)saao.ac.za ----------------------------------------------

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[vsnet-alert 28055] TCP J08374922+0134065: new WZ Sge-type dwarf nova with large early superhump amplitude
by Yusuke Tampo 14 Apr '25

14 Apr '25

TCP J08374922+0134065: new WZ Sge-type dwarf nova with large early superhump amplitude TCP J08374922+0134065 was discovered by Y. Nakamura on 3rd April at 14.7 mag. Based on the suggested counterpart (GALEX J083749.2+013407) with g=20.22(2) and the brightest ASAS-SN measurement with g~13.4 mag, the outburst amplitude is 6.8mag. http://www.cbat.eps.harvard.edu/unconf/followups/J08374922+0134065.html https://asas-sn.osu.edu/sky-patrol/coordinate/dce846f3-485d-4614-bace-a8b3e… Itoh-san has reported the time-resolved observations on 6th April and the light curve shows a double-peaked modulation with a period of ~0.059 d and an amplitude of 0.2 mag with possible eclipses. Thus TCP J08374922+0134065 is a new WZ Sge-type dwarf nova with high inclination. Time-resolved observations are strongly encouraged. Best regards, Yusuke -- ---------------------------------------------- South African Astronomical Observatory, Postdoc fellow 反保雄介 Yusuke TAMPO MAIL: tampo(a)kusastro.kyoto-u.ac.jp MAIL: yusuke(a)saao.ac.za ----------------------------------------------

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[vsnet-alert 28057] V854 Cen Apparent Decline
by Peter Williams 11 Apr '25

11 Apr '25

The bright southern RCB star V854 Cen appears to have commenced a decline as per the following visual observations: CENV854 20250312.780 74 WPX 10x50mm CENV854 20250402.445 80 WPX 10x50mm CENV854 20250411.465 93 WPX 20x80mm Full Moon Tks and regards Peter Williams Heathcote NSW

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[vsnet-alert 28056] X Ser in outburst
by Robert J. Modic 09 Apr '25

09 Apr '25

CCD Observations Object YYYYMMDD(UT) Mag Obs Chart Remarks SERX 20250408.305 15.72B MRV AAVSO MPO61; Err 0.03; Outburst SERX 20250408.313 15.52V MRV AAVSO MPO61; Err 0.02; Outburst Instruments: RCOS 24" w/FLI PL1603, AAVSONet (MPO61) Observer: Robert J. Modic (MRV)

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[vsnet-alert 28054] TCP J06455595+1210577: new SU UMa-type dwarf nova
by tonny.vanmunster＠gmail.com 02 Apr '25

02 Apr '25

Dear colleagues, I have just completed the analysis of my unfiltered CCD observations of TCP J06455595+1210577, obtained on Apr 01/02, 2025 at CBA Belgium Observatory. The data was collected using a 0.40-m f/10.0 telescope and QHY-268M CMOS camera under clear skies. This object was recently discovered by XOSS and announced as a possible CV candidate (see http://www.cbat.eps.harvard.edu/unconf/followups/J06455595+1210577.html) The light curve clearly reveals the presence of regular superhumps with an amplitude of 0.29 mag, establishing TCP J06455595+1210577 as a new SU UMa-type dwarf nova. A period analysis, using the ANOVA, Lomb-Scargle, Generalized-Lomb-Scargle and PDM methods (Peranso 3.1) yields a combined superhump period of 0.0731 +/- 0.0014d. The object was measured at mag CV = 16.2 on Apr 01st. Image calibration and photometry were performed using Phoranso, allowing me to simultaneously measure 4 other variables within the field of view of TCP J06455595+1210577. Further observations are encouraged to refine the superhump period. I will submit my observations to AAVSO, CBA and VSNET for further analysis. With kind regards, Tonny --- Tonny Vanmunster CBA Belgium Observatory CBA Extremadura Observatory http://www.cbabelgium.co <http://www.cbabelgium.com/> m PERANSO : The Light Curve and Period Analysis Software http://www.peranso.co <http://www.peranso.com/> m PHORANSO: Photometric Reduction and Analysis Software http://www.phoranso.com <http://www.phoranso.com/>

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[vsnet-alert 28053] outburst of LINEAR 23795703 - a CV of uncertain type in UMa
by Kirill Sokolovsky 25 Mar '25

25 Mar '25

The object LINEAR 23795703 = Gaia DR3 861540207303947776 = P_2.74a is listed as EW with the range 16.41 - 16.94 CV in the VSX https://www.aavso.org/vsx/index.php?view=detail.top&oid=322585 However, El-Badry et al. (2021) https://ui.adsabs.harvard.edu/abs/2021MNRAS.508.4106E/abstract identified it as an eclipsing cataclysmic variable (their object P_2.74a) that showed an outburst in 2015 according to ASAS-SN. El-Badry et al also present a spectrum and radial velocity curve. LINEAR 23795703 was found in outburst again on 2025-03-25.8886 UTC having CV=14.0 +/-0.1 in NMW survey images (135mm f/2.0 telephoto lens + unfiltered ST-8300M CCD). Best wishes, Kirill Sokolovsky for the NMW team

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[vsnet-alert 28052] EX Hya in outburst
by Rod Stubbings 13 Mar '25

13 Mar '25

EX Hya in outburst (NLDQ(UG)+E) HYAEX 250310.486 130 HYAEX 250313.469 106 HYAEX 250313.569 106 -- Rod Stubbings Tetoora Road Observatory Victoria, Australia Honorary Associate member Astronomical Society of Australia Telescope: "Infinity" 22" f/3.8 stubbo(a)dcsi.net.au http://rodstubbingsobservatory.wordpress.com/

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