[Stewart John Bean]

16.9 V mag on the early morning 20th May. Data is at AAVSO site. Stewart

[Stewart John Bean]

IX Dra at 14.6 V mag last night (with distinct variations over 15 minutes) which is typical for superoutbursts. Timing is consistent with expectations as described in VSSC 187. Data is at the AAVSO site.

IX Dra does seem fairly well behaved around its 60.5 days super cycle period.

[Stewart John Bean]

Only 18.0 V filter last night ( New Mexico AAVSOnet) . Probably the minimum before the superoutburst.

[Stewart John Bean]

They look good to me. Variation of about 0.15 mag is about right for superhumps, i think. So it all fits.

Thanks , Stewart

[Stewart John Bean]

Continues to look like a superoutburst. Stewart

[Stewart John Bean]

V mag 12.4 and 12.88 would suggest a superoutburst has started about 53 days from the previous start.

Jose Ripero Osorio (AAVSO) also reports 12.2 on May 4th.

If anyone can collect time resolved photometry to record super humps that would be good.

Stewart

 

[Stewart John Bean]

ER Uma is expected to start a superoutburst shortly (due date May 5th) so if anyone can help with observations that would be great. ER Uma is a reasonably bright target when in outburst, at about V mag 13, and is high in the sky in the evenings during May. Yesterday it was down at Vmag 15 so that may have been the minimum before a rise to superoutburst.

Stewart

[Stewart John Bean]

According to the recent trend of 60 days between superoutbursts, IX Dra is due to start its next outburst on May 9th – give or take a few days. 

Last night it was at V mag 16.7 and the day before at 17.8 (AAVSO BSM-NM). So it  may have one more normal outburst before the super starts. 

All contributions welcome to try to capture the time of the next superoutburst.

Stewart

[Stewart John Bean]

Vphot estimates the SN to be at V mag 14.85

[Stewart John Bean]

This is an image from 2021-04-09 09:00:20 obtained from New Mexico using iTel 021. 3 x 300 s exposure in V filter. 

[Stewart John Bean]

James DeYoung (USA) has uploaded three days of results –  including superhumps  starting at JD 2459285.5. So the outburst seems to have started at JD 2459285 giving a superoutburst period of 55.3 days since the last. This compares to 54.7 days for the previous period. So 55 days seems a good number to use for the next outburst although there may be an increasing trend as shown in the graph.

The next superoutburst may be around May 5th  give or take a week.

[Stewart John Bean]

ER UMa was last reported to be at a low state at 14.8 visual from Hungary. So a superoutburst should happen soon, but, unlike IX Dra , each period varies by upto +_ 7 days from the last. Observations would be most welcome in the next week – howling gales permitting.

The stream of AAVSOnet images I have relied upon for ER Uma, IX Dra and RZ Lmi ( all UGER stars) has paused for some reason.

Thanks in advance

Stewart

[Stewart John Bean]

Nick, Excellent. I think your observation caught it on the rise to the outburst.  

This fits with the recent average period between superoutbursts of 60.5 days.

Stewart

[Stewart John Bean]

Gary Poyner notes that Yutaka Maeda (Nagasaki, Japan)  has reported the following:

DRA IX    2021 03 10.74591     146:c    Mdy.VSOLJ    outburst

I also just had 14.7 Vmag at 2021/03/11 11:26:17  from itel T11. This compares with 14.5 Vmag for the two previous superoutbursts so most probably a superoutburst.

If anyone has observations for the last few days they could help firm up on the time of the super-outburst’s start.

Stewart

[Stewart John Bean]

In the next two weeks ER Uma will probably start a new superoutburst. This is based upon a superoutburst period of 55+/-5 days.

A graph of the superoutburst period against supercycle number is further up the thread – which shows this star “wanders” around 50 or 55 days for the super cycle period. 

ER Uma is a good target in the spring. Observations are encouraged.

Stewart

[Stewart John Bean]

IX Dra is approaching its March superoutburst. Based upon the current superoutburst period of around 60.5 days ( as described in VSSC 187) March 11 seems to be a likely start date. Yesterday IX Dra was at 17.4 V mag (AAVSOnet New Mexico) having risen from its quiescence low brightness of 18.0. It is possible there will be one more normal outburst and then the superoutburst as the time between outbursts is usually 5-6 days.

IX Dra is really a morning star at present, but is about 40 deg above the horizon at midnight in the UK.

Observations would be welcome over the next two weeks in order to determine the start of the superoutburst within a day.

Thanks in advance

Stewart Bean

[Stewart John Bean]

ER Uma probably in superoutburst at mag 12.6 V at 2021/01/17 04:44:36.

[Stewart John Bean]

Based upon observations from both VSS and AAVSO members, the graph below indicates the onset of the January superoutburst.

I estimate the start time to be JD 2459224.2 which in turn gives a supercycle period of 61.7 days since the November  event. Start times are arbitrary but in the absence of a definition (any ideas?) you have to go with something. The average value for P(sc) is then 60.5 days over the last eight cycles. Variations from this average only seem to be a few days so, with fingers crossed, we can mark our calendars for March 11 for the next superoutburst.

stewart

 

[Stewart John Bean]

AAVSOnet BSM_NM gave 14.25 V Mag at UTC 2021/01/12 04:58:12 which is similar to the previous two superoutbursts.

[Stewart John Bean]

Jim deYoung (DEY) reports the following from Virginia USA:

Got IX Dra last two nights, about 2 hours first night then 2.5 hours last night.

Not sure yet if super-humping but it is brighter than the standard inter-outbursts.

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