[Stewart John Bean]

Richard, Looks like you may have captured the start of the superoutburst. At the same time Steve Johnson made very similar observations reported to AAVSO.
A little later (UTC 2022/05/12 03:36:29 JD 2459711.65 ), using AAVSOnet New Mexico, I got a V magnitude of 13.1 which is in superoutburst territory. So it will probably remain bright for the next 5-10 days. If the superoutburst has started, it is 50 days from the last start – which is typical.

Regards

Stewart

[Stewart John Bean]

ER UMa is likely to go into superoutburst in the next few days. The last superoutburst started at 2459660. The superoutburst period varies between 45- 55 days. It is now 50 days since the last outburst.

Further observations this week would be timely.

Stewart

[Stewart John Bean]

An update on IX Dra recent behaviour. Observations are been made by the AAVSOnet telescope in New Mexico, by BAA-VSS, and by AAVSO members.

The most recent superoutburst was well recorded by AAVSOnet telescopes with a start around JD 2459688.

TESS contributed a detailed record of the superoutburst at JD 2459633.

The previous superoutburst was well recorded at JD 2459577.

The next previous superoutburst was well recorded on JD 2459520.

Graphing the most recent data gives the data in the attachment. This shows a declining trend from a peak around 60 days. The data point at JD 2459106 is almost certainly too high owing to limited observations. Observations were available only once the outburst had started so the start must be uncertain by a few days.

It seems that for IX Dra the trend towards longer superoutburst periods has paused. It may be reversing.

Thanks to all who have, and continue to, contribute to following this star.

• This reply was modified 2 years, 7 months ago by Stewart John Bean.

Attachments:

1. 

   IX-Dra-recent-superoutbursts.png
   

[Stewart John Bean]

The TESS satellite captured the most recent superoutburst completely. I estimate a start date of JD 2459633.

The most recent estimated super outburst start dates are complied below. Sources are BAA database, AAVSO DB and TESS results.

JD-2450000
9162.5 56.5
9224.2 61.7
9283 58.8
9344 61
9403 59
9463 60
9519 56
9577 58
9633 56 TESS image below

These give an average of 58.5 days.
Thanks to all contributing to these measurements
Stewart

Attachments:

1. 

   TESS-superoutburst-2459633.png
   

[Stewart John Bean]

I have come across a paper by Kato et al “Photometric study of new southern SU UMa-type dwarf novae

and candidates: V877 Ara, KK Tel and PU CMa”  

So I am occasionally imaging PU CMa as it may be coming up for a superoutburst in January/February. The other two will be better placed in the spring. 

In the meantime, I have joined G Poyner and IL Walton in following V1159 Ori.

[Stewart John Bean]

Measured ER UMa at 12.9 CV on 2021/12/28 03:08:50 using SLOOH in the Canaries. Hopefully some more results will arrive to refine the timing of what appears to be a superoutburst.

This is only ~45 days after the start of the last one. Most periods lie in the range 45 to 60 days – so quite short.  See  VSSC188 for a full graph of super cycle period over the last 200 or so cycles for context.

Stewart

[Stewart John Bean]

My prediction was one day early, but that is consistent with the superoutburst period very gradually getting larger. The last period was 26 days as I judge it.

Actually, this seasons light curve has good coverage as Sjoerd Dufoer (BE) has made 52 observations. Gary Poyner and Raymond Pearce have contributions as well. Thanks to all three.

Stewart

[Stewart John Bean]

I really mean those that can be observed from one of the remote telescopes at the latitude of, say, Santiago, Chile. There are not many in VSX but V1159 Ori is one. V1159 Ori is a good candidate (UGER) as it can be observed from both hemispheres giving a good temporal coverage. Brightness in the range 13.5 to 15.5 so easy enough. Its also one of the topics in M. Otulakowska-Hypka and A. Olech, MNRAS 433, 1338–1343 (2013)  so I will get into its ~50 day supercycle at some point.

Interest has been heighten by recent poor weather on Tenerife.

Stewart

now in Gloucestershire.

[Stewart John Bean]

As mentioned by Jeremy in VSSC 190 (the latest) several ER UMa stars are due a superoutburst before the year end. With a disclaimer on the accuracy of the dates, I copy below my expectations for four stars.

                   Superoutburst period (d)           Next superoutburst (give or take a few days)

RZ LMi                    25                                  Dec 11          Late evenings

V1159 Ori                ~50                                Dec 22       A late evening target

IX Dra                      60                                  Dec 30       An early evening target

ER Uma                   50-55                             Dec 30 – Jan 2        Late evening target

Stewart

[Stewart John Bean]

Jeremy,

Thx for your help. I’ve found UU Aql as a suitable target. Its listed as UGSS type in VSX although the data are a little sparse.

Stewart

[Stewart John Bean]

Plenty of images being taken on SLOOH Chile telescopes tonight by users.

I make is 13.5 CV in the image

[Stewart John Bean]

Here is an image from last night from SLOOH Chile 2. The marked star corresponds to the SN coordinates

[Stewart John Bean]

I’ll give it a go from Slooh Chile tonight

[Stewart John Bean]

It looks like Nick James’s observation on the evening of Oct 31 with an unfiltered magnitude of 14.81 marks the start of the outburst. With a JD of 2459519.29 this is only 56 days since the previous superoutburst but within the range of many recent results reported in VSSC 187. 

Lets see how long this superoutburst lasts.

My next target is V1504 Cyg whose next superoutburst is due in a two weeks time.

[Stewart John Bean]

Looking at the data reported to the BAA and AAVSO databases, the start of the next superoutburst could be in 3-4 days time.

A normal outburst peaked at mag 15.3 (CV)  on the evening of 29 Oct (NDJ and I) was probably the last before the superoutburst.

IX Dra is quite well placed in the evening sky. Good luck.

Stewart 

[Stewart John Bean]

I note that many of the AAVSOnet instruments are small: BSM New Mexico and BSM Berry (Perth , Aust) are both 180 mm. For VS use they are suitable and are busy – when working.

[Stewart John Bean]

David

I have experience of both the iTel and SLOOH telescopes as I do not have my own kit.  I do not have my own kit because of the hassle of looking after the site, the dome, the telescope, insurance, computer hardware, software, internet access etc. I can understand why people might be concerned about setting up a BAA telescope from scratch. If it must be a BAA telescope  then I would probably recommend an existing telescope farm to cover most of these hassles at , I think, about £300-400 a month. That still leaves the issue of organising how individual users will get time on the instrument.

The other option is to subsidise members using iTEL or SLOOH ( or others). SLOOH offers five targets per night for $300 a year with various filters depending on their eight telescopes. I do VS observing.  Sites are available in both hemispheres. This route seems to be the lowest risk to get started as there is an easy way to bail out if it all goes wrong.

The AAVSOnet instruments do run well for periods but then stop for a long time as equipment goes down. Its a bit mixed in my experience.

Stewart Bean (SLOOH member and ex iTEL member)

[Stewart John Bean]

Got a few images now from the AAVSOnet SRO telescope in the USA on CG Dra. It has been down for some time.

Hopefully more will follow.

Stewart

[Stewart John Bean]

IX Dra was at V mag 17.9 on 20 Sept 04.42 UTC marking the end of the superoutburst. Almost immediately a normal outburst has started. I think the start of this superoutburst was recorded well and I expect a few more observations to appear in due course. 

Thanks to N D James and N L Joslin for observations in the BAA database.

The next superoutburst will be around fireworks night!

Stewart

 

[Stewart John Bean]

According to the BBC, help has arrived in the form of the Spanish PM.

[Author]

Posts