AAVSO: American Association of Variable Star Observers

Proposal #154

Proposer (43151) Stewart Bean (sjbeanmail@aol.com) obscode: BENS
Assigned To(3663) Dirk Terrell
Date SubmittedOct. 5, 2020

A proposal to monitor the expected IX Dra superoutburst from Nov 1 to Nov 30th 2020

I have been analysing the TESS data for IX Draconis and reading the literature on the superoutburst period for this star. M. Otulakowska-Hypka, A. Olech et al (2012) suggest that the super outburst period is increasing from 44 days (1990) to 58 days (2010) implying about 62-64 days in 2020. TESS data, processed with Lightkurve package, suggests that the most recent superoutburst period ( JD 2458700 to 2459040 ) is best fitted with a folding time of 60.9 days. This gives JD 2459165 as the likely time for the start of the next superoutburst. Superoutbursts are about 20 days of duration. The timing of the start of the next superoutburst would establish a superoutburst value for 2020.

The scientific interest lies in determined if IX Dra is really evolving one of its key parameters.

I propose to monitor the expected November superoutburst as TESS is presently monitoring the southern hemisphere. Snapshot photometry in the V band is requested each day from Nov 1 to Nov 30 if possible.


Stewart Bean

Target RA (H.HH) Dec (D.DD) Magnitude Telescope Observation Frequency Expiration Date Proprietary Term
IX Dra 18.208742 67.07939 18.8–14.7 BSM_NH2 April 7, 2021 No


(3663) Dirk Terrell — Oct. 7, 2020, 1:22 p.m.

Arne suggest we wait on this until we get another 24" telescope online (soon).

(4726) Kenneth Menzies — Oct. 9, 2020, 5:10 p.m.

Test plan committed to SRO and NH2. Data will be shared to both Jeremey and Stewart. They will coordinate analyses.

(43151) Stewart Bean — Oct. 10, 2020, 5:13 p.m.

I have noticed that the first images ( …….101') taken on both 8 and 9 Oct have some tails to the star images.

(43151) Stewart Bean — Oct. 16, 2020, 6:37 a.m.

Ken, I assume that weather has paused the observations.
I have images from two nights Oct 8 , 9 in my FTP location.
The images are fine for judging the onset of outburst - which is the aim of the project.

Sunday 18th Oct looks more promising according to "clearoutside.com".


(43151) Stewart Bean — Nov. 15, 2020, 5:01 p.m.

A lot of images have come through today and yesterday -as if there has been some bottleneck that has now been released. All but the latest set are now in the database.

We have been able to capture the start of the superoutburst to 2459162.5 (actually by "DEY" /AVVSO ) . This has allowed an estimate of 59.5 days for the supercycle series starting at JD 2458686 detected by TESS. This compares to 44 days over two outbursts (1990) and 58 days over three superoutbursts in 2010 (M. Otulakowska-Hypka, A. Olech et al 2012). So these measurements suggest that the period between superoutbursts may be increasing by about one day per decade. By the time the TESS Year 4 program finishes in 2022, we will have a good measure of the average over a couple of years and the variation around this mean.

I have been using the V filter results only, so if you wish to drop the "clear" images thats fine by me.

(43151) Stewart Bean — Dec. 26, 2020, 12:14 p.m.

As discussed could you restart observations of IX Dra in order to capture the next superoutburst due around Jan 7th. So ideally, a Jan1st restart would be good. I realise that IX Dra is quite low elevation now so not an easy target, and with SRO being unserviceable, it may be best to use BSM NH again. Again the project aims to time the start of the outburst. for this, I found BSM NH2 images fine for the task.



(2108) Arne Henden — Dec. 26, 2020, 12:29 p.m.

This is a tough target from BSM_NH2 because it is far north, where I have substantial tree cover. BSM_NM might also have difficulty, as that is the direction that the roof resides, but I'd choose that one first.

We have a new telescope in the network, MPO61, that could possibly be useful in the desired timeframe. TMO61 is also available, so I think we might be able to monitor IX Dra for an outburst. If Ken wants to set up plans for those two sites, we can start working with adjusting exposure times.

(43151) Stewart Bean — Dec. 28, 2020, 9:19 a.m.

OK thanks for looking into it. I realise its difficult at this time of the year.

(43151) Stewart Bean — Jan. 6, 2021, 2:13 p.m.

Early morning suggestion for IX Dra.

I have successfully used the itel T5 instrument (200 mm and 300 sec) in New Mexico at 5:30 am local time to image IX Dra just today.
Could BSM_NM2 or BSM_TX be used early in the morning to observe the next superoutburst expected in a few days time?


(43151) Stewart Bean — Jan. 14, 2021, 10:32 a.m.

I see that BSM NH2 is running. Can I ask that IX Dra V filter be added to this instrument now that SRO is down. IX Dra is, at the time of writing, in a superoutburst.

(43151) Stewart Bean — April 19, 2021, 7:38 a.m.

Very odd image from SRO last night. Tracking seems to be out by degrees

Comments on this proposal are closed.