Quiescence: 2461269.47560 20.551 0.2222 CV --- Pavol A. Dubovsky Variable Star Section, Slovak Astronomical Society and Slovak Union of Astronomers Asociación Astronómica de Piconcillo var.kozmos.sk www.bombol.space On 16/08/2026 05:40 PM, t9005780498--- via vsnet-campaign wrote:
Dear Colleagues,
We are planning an observational campaign for the object MASTER OT J173618.08+752123.3. This is an AM CVn-type system, which we confirmed spectroscopically using the 6-meter BTA telescope.
An outburst of J1736 was discovered by the MASTER network. Based on VSNET data, K. Naoto suggested that J1736 is an analogue of V803 Cen, with an outburst cycle duration of approximately 250 days (vsnet-chat 8472).
Analysis of TESS and ZTF data revealed that the outbursts have a complex shape, exhibiting a precursor and a series of rebrightenings following the main outburst. The light curve resembles that of KL Dra (see Salazar Manzano et al. 2026 2026PASA...43...70S); however, only complex-shaped "superoutbursts" are observed, and no "normal outbursts" have been detected. In terms of photometric behavior, the analogues of J1736 are Gaia 16all and SDSS J1043+5632 (see Pichardo Marcano et al. 2021 2021MNRAS.508.3275P). Refined outburst cycle value is 215-225 days.
Possible periodic modulations with periods of 31 and 14.8 minutes have been detected in TESS data during a superoutburst. Observations during quiescence using a 2-meter telescope reveal a periodicity of 32.7 minutes and possible shallow (0.2 mag) eclipses.
We plan to conduct photometric observations in quiescence using large telescopes to confirm the orbital period and model the light curve and also photometric monitoring in outburst using meter-class instruments. However, to coordinate observations, it is important for us to know the state of the object - quiescence or outburst - every night.
Could you please take 3-5 CCD images on every clear night to determine the star's state - whether it is in quiescence (~20.5 mag) or outburst (~17 mag) and promptly submit the obtained magnitude values or limits to the AAVSO, VSNET and in reply emails? All observers participating in the observations will be included as co-authors on the paper.
Please find data about the object at https://vsx.aavso.org/index.php?view=detail.top&oid=398737
I look forward to hearing from you. Many thanks in advance.
Best regards, Alexander Tarasenkov