[Stewart John Bean]

Today I noticed the graphs had gone from my posts . I have put the latest back into the 26th Oct post. Any thoughts on the reasons? Are some formats preferred?

Nick James, Gary Poyner and David Swan all report IX Dra at fainter than 17 over the weekend. So back to its low state for a day or so. We can expect a few more normal outbursts at 4-5 day intervals before the super outburst around Nov 14th ( I’m sticking my neck out a bit here, I know).

Stewart

[Stewart John Bean]

Thanks . That fits with the normal outbursts being about 5 days apart before a superoutburst. In the attachment from TESS data you can see the normal outbursts become more intense and 4-5 days separation. IX Dra never really goes into quiescence. Stewart

[Stewart John Bean]

The graph summaries the results to date. 

There seem to have been three normal outbursts at 3-5 day intervals reaching 16.5 magnitude (V) at peak. The project is trying to time the next superoutburst to check the apparently regular 61+-2 day period suggested by TESS results. The next superoutburst is likely in the middle of November. If we can maintain observations at this frequency then we will have an uncertainly of only a day of two.  Thanks to all observers who have contributed. Bean data is courtesy of AAVSOnet.

Stewart and Jeremy

[Stewart John Bean]

 I have the following for V1391 Cas  from  23 Sept 2020:

V filter  12.95,

B filter 14.4 ,

I filter    10.19

Values are in the database. Stewart

[Stewart John Bean]

Hi, Just  found this thread and wondered the current status?

I use the itelescope network and might consider joining a BAA group

Stewart

[Stewart John Bean]

I make it 11.8 mag through V filter this morning, Aug 5th at 01 :43. (T18, Nerpio, Spain.)

I make it 11.1 mag through the R filter.

For both measurements the reference star was 11.2 on the AAVSO chart. I’ll try to get these uploaded via Muniwin once I get the hang of it.

[Stewart John Bean]

I find the following from this morning using T5 (250 mm) in New Mexico at JD 2459062.902. I used AstroimageJ

With V filter, nova was 12.9 using 11.2 ,14.3, and 12.6, reference stars in AAVSO chart

With R filter, nova was 12.4 using 12.6 in AAVSO chart

With B filter, nova was 13.3 using 12.6 and 13.7 in AAVSO chart

Seems quite bright through the red filter. Stewart

[Stewart John Bean]

I was not able to resolve the nova from its adjacent star in images taken overnight with the T18 scope in defocus mode for photometry. Not sure how to proceed. Stewart

[Stewart John Bean]

I obtained this image using the T30 500 mm telescope at Siding Spring Observatory . It is the average of three 600 s exposures with a luminance filter.

[Stewart John Bean]

Hi,Here is a link to the arXiv website posting an abstract a paper on a Saturn sized planet discovered , in part, though citizen scientists.  https://arxiv.org/abs/1909.09094 

The first line of the abstract is reproduced below:

We report on the discovery and validation of TOI-813b (TIC 55525572 b), a transiting exoplanet identified by citizen scientists in data from NASA’s Transiting Exoplanet Survey Satellite (TESS) and the first planet discovered by the Planet Hunters TESS project.

I am one of many volunteers, probably including other BAA members, who found the light curve dip last winter. It is interesting that for transits that are infrequent ( this planet has an orbital period of about 80 days) , the automated searches are less able to detect the dip as they depend upon reoccurring events. So transits from hot Jupiters with short periods are easily found but cold Jupiters with long orbital periods are more difficult. So there is a role for volunteers even if you do not possess a telescope.

Regards

Stewart

[Stewart John Bean]

Having looked at the front page of the August journal , I am also struck by how coarse the material seems to be. Could the absence of fine dust be linked to the accumulation of charge on particles under the influence of the solar wind or deep UV? Electrostatic repulsion between individual particles and Bennu itself will be larger than the gravitational force for all but the larger particles assuming they both charge with the same polarity. So only big pieces can grow into something like Bennu.

In the outer solar system far from the solar wind charging will be much less significant and smaller particles can clump into a comet precursor. 

Stewart 

[Stewart John Bean]

I obtained the following three results with the T5 telescope ( 250mm reflector)  in New Mexico on 26 May. Using a 14.29 mag star as reference, AstroImageJ gives 15.55(V), 15.96(Red) and 15.48(Blue). 

Stewart

[Stewart John Bean]

An image from New Mexico (T14)  showing AL Com at the limit of detectability for 106 mm refractor with V filter. Still easily detected with a Luminance filter. Something for every section here with galaxies, a variable star, and  a tumbling object crossing the 300s exposure field. A second image also captured this object suggesting it was not a CCD defect or other anomaly.

stewart

 

[Stewart John Bean]

Mike, How did you get to use this telescope? Stewart Bean

[Stewart John Bean]

Repeating this field on May 5th ( following my first observation on 28 April), Al Com is only just detectable with itelescope’s T14 106 mm refractor with a V filter. AstroImageJ gives an magnitude estimate of 15.0 but the S/N and S/B  are poor and the reference star is magnitude 11.9 – perhaps too bright to be the best choice.

However, using a Luminance filter it is still easily visible.

[Stewart John Bean]

AL Com now at 14.34 as of 28 April. I used the T14 telescope in USA ( 100 mm refractor and cooled CCD) with a 300 s exposure , V filter, defocussed. AstroImageJ produced the estimate of magnitude. There are also a large number of galaxies close to M88/AL Com.

Stewart

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