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[vsnet-campaign-dn 16982] MASTER OT J055845.55+391533.4: new SU UMa-type dwarf nova
by tonny.vanmunster＠gmail.com 24 Feb '23

24 Feb '23

Dear colleagues, I have just finished analysing my unfiltered CCD observations of MASTER OT J055845.55+391533.4 obtained on 2023, Feb 22/23 at CBA Extremadura Observatory (Spain) using a 0.40-m f/5.1 telescope and SX-46 CCD camera under relatively clear skies. The resulting light curve clearly shows the presence of regular superhumps (4 in total) with an amplitude of 0.20 mag, establishing MASTER OT J055845.55+391533.4 as a new SU UMa-type dwarf nova. A period analysis, using the ANOVA, Generalized-Lomb-Scargle, PDM and Conditional Entropy methods (Peranso 3.0) yields a combined superhump period of 0.0553 +/- 0.0004d. The object was at mag CV = 14.4 on Feb 23rd. I will send my observations to AAVSO, CBA and VSNET for further analysis. Best regards Tonny --- Tonny Vanmunster CBA Belgium Observatory CBA Extremadura Observatory <http://www.cbabelgium.com> http://www.cbabelgium.com PERANSO: The Light Curve and Period Analysis Software http://www.peranso.com

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[vsnet-campaign-dn 16981] GDSJ0703457-063947: IW And star
by Taichi Kato 24 Feb '23

24 Feb '23

GDSJ0703457-063947: IW And star Using ATLAS forced photometry (Tonry et al. 2018; Shingles et al. 2021), this object turned out to be an IW And star (typical behavior in 2022). The variation was more heartbeat-like in 2020-2021, when the object was slightly brighter. This may be a suggestion of various IW And-type behavior depending on the mass-transfer rate.

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[vsnet-campaign-dn 16980] MASTER OT J055845.55+391533.4 superhumps?
by Taichi Kato 24 Feb '23

24 Feb '23

MASTER OT J055845.55+391533.4 superhumps? Kiyota-san reported observations. The data appear consistent with a longer superhump period of a hydrogen-rich system. The data, however, were not enough and more observations are needed (the outburst behavior is unusual for ar ordinary SU UMa star).

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[vsnet-campaign-dn 16979] MV Leo: unusual start of standstill
by Taichi Kato 23 Feb '23

23 Feb '23

MV Leo: unusual start of standstill Using ATLAS and ZTF data, I found that this object entered a standstill almost directly from a low state in 2020 Mar.-Apr. Such behavior is unexpected. This standstill ended with an outburst like an IW And star.

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[vsnet-campaign-dn 16978] 6dFg0002074-374917: deeply eclpsing likely SU UMa star
by Taichi Kato 23 Feb '23

23 Feb '23

6dFg0002074-374917: deeply eclpsing likely SU UMa star Using ATLAS forced photometry (Tonry et al. 2018; Shingles et al. 2021). Porb=0.0711838(1) d. 1.5-mag deep eclipses and orbital humps in quiescence. Likely superoutburst in 2020.

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[vsnet-campaign-dn 16977] ASASSN-14ak most likely superoutburst
by Taichi Kato 23 Feb '23

23 Feb '23

ASASSN-14ak most likely superoutburst (Porb=0.08869) YYYYMMDD(UT) mag observer 20230211.0933 18.240o (ATLAS Forced Photometry (Tonry+2018, PASP 130, 064505)) 20230212.2114 17.939o (ATLAS Forced Photometry (Tonry+2018, PASP 130, 064505)) 20230212.2142 17.992o (ATLAS Forced Photometry (Tonry+2018, PASP 130, 064505)) 20230212.2195 18.049o (ATLAS Forced Photometry (Tonry+2018, PASP 130, 064505)) 20230212.2255 17.917o (ATLAS Forced Photometry (Tonry+2018, PASP 130, 064505)) 20230212.2295 17.910o (ATLAS Forced Photometry (Tonry+2018, PASP 130, 064505)) 20230212.2304 17.840o (ATLAS Forced Photometry (Tonry+2018, PASP 130, 064505)) 20230212.2630 17.972o (ATLAS Forced Photometry (Tonry+2018, PASP 130, 064505)) 20230212.2686 17.907o (ATLAS Forced Photometry (Tonry+2018, PASP 130, 064505)) 20230214.9525 18.172o (ATLAS Forced Photometry (Tonry+2018, PASP 130, 064505)) 20230214.9557 18.175o (ATLAS Forced Photometry (Tonry+2018, PASP 130, 064505)) 20230214.9634 18.088o (ATLAS Forced Photometry (Tonry+2018, PASP 130, 064505)) 20230214.9777 18.214o (ATLAS Forced Photometry (Tonry+2018, PASP 130, 064505)) 20230216.1413 18.197c (ATLAS Forced Photometry (Tonry+2018, PASP 130, 064505)) 20230216.1641 18.070c (ATLAS Forced Photometry (Tonry+2018, PASP 130, 064505)) 20230216.1659 18.136c (ATLAS Forced Photometry (Tonry+2018, PASP 130, 064505)) 20230216.1683 18.237c (ATLAS Forced Photometry (Tonry+2018, PASP 130, 064505)) 20230216.1697 18.225c (ATLAS Forced Photometry (Tonry+2018, PASP 130, 064505)) 20230216.1701 18.240c (ATLAS Forced Photometry (Tonry+2018, PASP 130, 064505)) 20230216.1733 18.023c (ATLAS Forced Photometry (Tonry+2018, PASP 130, 064505)) 20230216.1872 18.179c (ATLAS Forced Photometry (Tonry+2018, PASP 130, 064505)) 20230220.1531 18.373c (ATLAS Forced Photometry (Tonry+2018, PASP 130, 064505)) 20230220.1567 18.391c (ATLAS Forced Photometry (Tonry+2018, PASP 130, 064505)) 20230220.1599 18.265c (ATLAS Forced Photometry (Tonry+2018, PASP 130, 064505)) 20230220.1662 18.319c (ATLAS Forced Photometry (Tonry+2018, PASP 130, 064505)) 20230222.9545 13.374o (ATLAS Forced Photometry (Tonry+2018, PASP 130, 064505)) 20230222.9577 13.372o (ATLAS Forced Photometry (Tonry+2018, PASP 130, 064505)) 20230222.9629 13.392o (ATLAS Forced Photometry (Tonry+2018, PASP 130, 064505)) 20230222.9729 13.376o (ATLAS Forced Photometry (Tonry+2018, PASP 130, 064505)) 20230223.487 133 (Rod Stubbings)

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[vsnet-campaign-dn 16976] ASASSN-14ak likely superoutburst
by Taichi Kato 23 Feb '23

23 Feb '23

ASASSN-14ak likely superoutburst YYYYMMDD(UT) mag observer 20230223.487 133 (Rod Stubbings)

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[vsnet-campaign-dn 16975] DDE 139 outburst
by Taichi Kato 23 Feb '23

23 Feb '23

DDE 139 outburst Possible superoutburst (suspected type from past ZTF and ATLAS data). Gaia23avk AT2023cmu 2023-02-22 02:07:36 203.00327 -4.90294 16.03 18.83 1.28 CV 2023-02-23 12:54:57 5 mag outburst in known CV http://gsaweb.ast.cam.ac.uk/alerts/alert/Gaia23avk/ YYYYMMDD(UT) mag observer 20230215.8431 <173C (Masayuki Moriyama) 20230219.8683 <169C (Masayuki Moriyama) 20230222.0225 16.111o (ATLAS Forced Photometry (Tonry+2018, PASP 130, 064505)) 20230222.0243 16.112o (ATLAS Forced Photometry (Tonry+2018, PASP 130, 064505)) 20230222.0394 16.106o (ATLAS Forced Photometry (Tonry+2018, PASP 130, 064505)) 20230222.0448 16.126o (ATLAS Forced Photometry (Tonry+2018, PASP 130, 064505)) 20230223.3467 15.820c (ATLAS Forced Photometry (Tonry+2018, PASP 130, 064505)) 20230223.3810 16.096c (ATLAS Forced Photometry (Tonry+2018, PASP 130, 064505)) 20230223.3842 16.075c (ATLAS Forced Photometry (Tonry+2018, PASP 130, 064505))

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[vsnet-campaign-dn 16974] ASASSN-18of possible outburst
by Taichi Kato 22 Feb '23

22 Feb '23

ASASSN-18of possible outburst Likely SU UMa star from ATLAS data (long outburst + rebrightening in 2018). YYYYMMDD(UT) mag observer 20230130.7011 <155c (Yutaka Maeda) 20230204.6965 <159c (Yutaka Maeda) 20230210.7105 <150c (Yutaka Maeda) 20230214.6946 <148c (Yutaka Maeda) 20230215.6963 <163c (Yutaka Maeda) 20230221.6485 157:c (Yutaka Maeda)

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[vsnet-campaign-dn 16973] V476 Cyg outburst (Nova Cyg 1920)
by Taichi Kato 22 Feb '23

22 Feb '23

V476 Cyg outburst (Nova Cyg 1920) Gaia detected an outburst. See https://ui.adsabs.harvard.edu/abs/2022arXiv220306320K/abstract http://vsolj.cetus-net.org/vsoljno95.pdf The current outburst is bright and may show superhumps. Gaia23ava AT2023clo 2023-02-20 16:33:55 299.60206 53.61855 16.49 17.78 0.35 CV 2023-02-22 16:29:11 Outburst in known CV V0476 Cyg http://gsaweb.ast.cam.ac.uk/alerts/alert/Gaia23ava/

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