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ER Uma and RZ Lmi: Observations requested.

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sjbean's picture
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ER Uma and RZ Lmi: Observations requested.

Following on from the IX Dra observations ( which continue at AAVSOnet), I am now monitoring ER Uma and RZ Lmi in order to time their superoutbursts. The supercycle period, P(sc),  for these two are relatively short and apparently increasing as shown below from M. Otulakowska-Hypka‹ and A. Olech MNRAS 433, 1338–1343 (2013).

My estimate from the AAVSO, ASAS-SN and Lasair records suggests that their P(sc) values are around 44 and 24 days. The interest is to determine P(sc) for this observing season and check the above graphs. Fortunately, the AAVSOnet committee have agreed to a request to contribute one of their robotic telescopes to the task. 

ER Uma may be starting a superoutburst now. RZ Lmi could be next week although both dates are long extrapolations. 

I would appreciate help with these observations although both are really morning stars at present: only 35 deg above the horizon at midnight but overhead at 06:00. Ideal for robotic telescopes.

Thanks in advance

Stewart Bean

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RZ Lmi and ER Uma both seem to have started a superoutburst

RZ Lmi was 14.26 at 2020/11/24 11:06:56 UT

ER Uma was at 12.8 at 2020/11/24 11:13:38 UT

Both were measured using  AAVSOnet.