IX Dra: observations requested

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  • #583677
    Stewart John Bean
    Participant

    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.
    #583723
    Stewart John Bean
    Participant

    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

     

    #583910
    Stewart John Bean
    Participant

    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

    #583938
    Stewart John Bean
    Participant

    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

    #583940
    Nick James
    Participant

    My latest observation was on March 9.8 when it was 15.39 (ref Gaia G). My data is in the VSS database.

    #583942
    Nick James
    Participant

    And 14.89 just now (March 11.84) in a howling gale.

    #583944
    Stewart John Bean
    Participant

    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

    #584156
    Stewart John Bean
    Participant

    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

    #584188
    Stewart John Bean
    Participant

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

    #584200
    Stewart John Bean
    Participant

    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.

    #584443
    Stewart John Bean
    Participant

    IX Dra has been observed by AAVSOnet New Mexico scope, in combination with Vphot, as follows.

    2021/07/09 03:45   14.57 V

    2021/07/10 04:44    14.7 V

    These are values consistent with a superoutburst. There has been a week of no observations so the start of the outburst is not yet clear. 

    Stewart

    #584444
    Nick James
    Participant

    My last observation was on July 7.9 at 16.52. It’s in the BAA database. Richard Sargent also got some observations later that night at around 16.10. They are in the database too.

    #584487
    Stewart John Bean
    Participant

    Nick, These two observations constrain the start of the superoutburst  rather well giving a super outburst period of about 59 days. This is in line with recent periods. IX Dra does seem to be fairly consistent. Until the next time of course.

    Cheers 

    Stewart

    #584634
    Stewart John Bean
    Participant

    IX Dra has a superoutburst period of around 60 days – give or take a day. This means the next superoutburst is likely to be around September 5 -7th.  The most recent magnitude I have is around 17.7 CV (on 2459456.5 Aug 30)  using SLOOH Canary 2. Further observations to capture the start of the superoutburst would be welcome.   

    #584654
    Nick James
    Participant

    The last two nights it has been brighter than mag 15 so the outburst looks to be on schedule. Tonight (Sept 6) I have 14.7 unfiltered.

    #584655
    Stewart John Bean
    Participant

    Nick,  I’m pleased to see your results in the BAA database as neither SLOOH or AAVSOnet have delivered results for last night. Slooh had it at CV 14.9 at UTC 2021/09/06 00:10:23.  Looks like the superoutburst is under way and it was around the time expected. Normally they  last for about 10 days. Stewart

    #584658
    Stewart John Bean
    Participant

    AAVSOnet New Mexico gave 14.7 V filter  on 2021/09/07 02:29:22.

    #584722
    Stewart John Bean
    Participant

    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

     

    #584878
    Stewart John Bean
    Participant

    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 

    #584882
    Stewart John Bean
    Participant

    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.

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