[Stewart John Bean]

Thats a big list for one night. We need some one to get the list down to a more manageable size and into different categories. Stewart

[Stewart John Bean]

IX Dra is not a period bouncer but sits with ER Uma and V1159 Ori on the upper branch of the evolutionary curve.
I have started a short note for the next VSSC describing the topic.

As an aside, the position of DI Uma on the graph is curious as the absence of RZ Lmi (its twin) on the graph. DI Uma seems to have a solid orbital period and yet its “twin” RZ Lmi has not revealed its orbital period “as it is usually in outburst”. I am wondering if the orbital period for DI Uma is wrong. I think only time resolved Doppler spectroscopy has a chance as the TESS coverage is poor and noisy.

DI Uma is not well observed and is also close to a standard star. Because it is very active (half the time in superoutburst) only very regular observations actually show the light curve clearly.

Stewart

[Stewart John Bean]

Hi ,
I have been looking into IX Dra and its status as a “period bouncer” reported by Olech, A. et al 2004.
Their Fig 12 places IX Dra as a period bouncer. It turns out that decision is based upon an accurate understanding of the difference between P(sh) and P(orb). Determining P(orb) has not been easy. Thorstensen has recently (2020) determined P(orb) accurately and to check I looked at the TESS results for IX Dra. TESS date from the normal outburst sections of the light curve agrres with Thorstensen. So IX Dra can be moved to the upper branch of the curve in the attached figure and join its ER Uma cousins.

Stewart

Attachments:

1. 

   Olech-A-2004-Figure-12.png
   

[Stewart John Bean]

I have summarised this topic and submitted to the VSSC.

Next point of interest is IX Dra.

Stewart

[Stewart John Bean]

V1159 Ori has now shown a superoutburst event starting on Jan 7 and running to Jan 15 approximately.

It has been 126 days since the last superoutburst making this interval in the observing record that I am aware of. This continues an irregular trend towards longer intervals between superoutbursts. Normal outbursts have continued as usual. Ian’s observations above are the last before the outburst started.
I interpret this as showing that the flow of material from the donor star has not stopped. Rather the quantity flowing has fallen to a point where conditions needed for a superoutburst have not been present.

Time now to write the work up and submit to VSSC.

Thanks to all who have contributed. As usual the interest continues. Has this been an outlier or is the next superoutburst only 40 days away?

STewart

[Stewart John Bean]

Guys, Thank you all who have contributed observations over Xmas.

The pattern remains of continuing normal outbursts – see upto date light curve attached. It is now ~120 days since the last superoutburst. I have worried about having missed a superoutburst but cannot see where it may have occurred.
Is there a category for stars only showing normal outbursts?

Will check on the deadline for the next VSSC in preparation for a write up.

Stewart

Attachments:

1. 

   V1159-Ori-5-Jan-2026.png
   

[Stewart John Bean]

Hi Ian,
Yes there was a normal outburst peaking on the 19th peaking at about 13.5 and returning to 15 on subsequent days. Thanks for the observation.
However, Still no super outburst . So we are at 110 days since the last superoutburst – which is the longest wait yet.
Seems as if the flow of material from the donor star is not stable for V1159 Ori.
Stewart
PS I see you are in the ALTAIR group with one Sebastian Von Harriach. Is this Sebastian a electron microscope professional? I am ex Zeiss

[Stewart John Bean]

A milestone for V1159 is approaching.

According to the observations in the AVVSO record for V1159 Ori, it is now 98 days since the last superoutburst. This exceeds the previous interval of about 70 days. So either the observations have missed a superoutburst or we continue to see normal outbursts but no superoutburst. I am inclined to think that conditions for triggering a superoutburst are not present. Longer intervals between superoutbursts has been the trend for V1159 Ori. At this rate, if V1159 Ori were discovered today it would not meet the criteria for being classed as a ER Uma type CV. However, normal outbursts do continue and these may be a better guide to classification – which is arbitrary anyway.

Once the next superoutburst occurs and provides another data point on the graph, I will write up for the VSSC.

[Stewart John Bean]

Ian,
Interesting that you are in Spain. One of the challenges is to observe V1159 Ori ( Declination only -3 degrees) around conjunction. The best place would be from the Equator. All my reported observations have been via an AAVSOnet project.
I forgot to use the Slooh Canary 2 (27 deg latitude) instrument this summer for the job – especially as it now has a V filter.

VSX gives a period of 90min for V1159 Ori.

Stewart

[Stewart John Bean]

For V1159 Ori an observer on the equator would be able to fill in, to some extent, the summer gap in observations.

[Stewart John Bean]

How do I look up the ZTF code for ER Uma? It will be something like ZTF******* Stewart

[Stewart John Bean]

TMO61 (AAVSOnet) just sent their first, if slightly streaky, image. I thought they had forgotten about CG Dra. Hopefully the first of many.

16.7 CV – so mid range.

[Stewart John Bean]

I get 16.74 CV at
2024/06/29 04:14:01
Slooh Canary 2

[Stewart John Bean]

Got Slooh Canary 2 booked for this evening.

[Stewart John Bean]

I have tried to answer my own question without particular success. Certainly gamma ray bursts (GRB) are detected about once per day by satellites. Close supernovae may have caused extinction events and ground based radio astronomy may have a chance. I think it is possible that at a dark site and with a whole sky detector sensitive to green light (from excited N2) you may detect something. I am not going out in a deck chair waiting for a few seconds flash!

The largest GRB so far was GRB 221009A ( on 2022 October 9) which was associated with a supernovae 2 billion light years away. . Search “A Significant Sudden Ionospheric Disturbance Associated with Gamma-Ray Burst GRB 221009A” . https://iopscience.iop.org/article/10.3847/2515-5172/ac9d2f/meta
The event was detected with a very low frequency radio SuperSID monitor.

Are the radio section aware?

Now a recurrent nova is not a supernovae and the radiation is not focussed in our direction, but it is a million times closer so who knows.

Stewart

[Stewart John Bean]

I listened to Brad’s enthusiastic delivery.
~Interesting to think about detecting a neutrino flash. Now I do not have a suitable detector in my back yard, but it triggered the thought:

Will the X ray/gamma ray flash be sufficient to be detected as a blue/green scintillation flash from the upper atmosphere?

Stewart

[Stewart John Bean]

~I checked that saturation effects are not relevant by using a short exposure of 10 s instead of 45s. The V magnitude is in line with the trend.
So no further to understand why Slooh Chile 2 V produces much lower magnitude values.
Stewart

[Stewart John Bean]

Andrew Pearce has kindly provided me with the three sequences used on each of the telescopes he uses.

I have applied each sequence to the Mar 15 Slooh V image in question and found that all sequences, plus AAVSO, give a Magnitude of 12 or there about. Min is 11.86; max is 11.99.

I will now reply to Andrew with fuller details and share the Mar 15 image with him via Vphot.

Stewart

[Stewart John Bean]

thanks Robin. Redness is probably at the centre of this topic.

[Stewart John Bean]

I have emailed Andrew Pearce to ask for the sequence he is using.

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