Jeremy Shears

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Viewing 20 posts - 181 through 200 (of 547 total)
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  • in reply to: Nova in Aries? #585028
    Jeremy Shears
    Participant

    It looks like this UGWZ system is on the turn: mag 14.4 last night Dec 19 (CV; Gary Poyner)

    in reply to: Betelgeuse #585015
    Jeremy Shears
    Participant

    I can’t believe it’s 2 years since the great dimming of Betelgeuse. The latest light curve was shown in the recent  Christmas Meeting Sky Notes by Nick James. There have been a couple of conferences dedicated to Betelgeuse in the last year. Here is a nice paper on “The curious case of Betelgeuse”, by Jacco van Loon (Keele U.) posted in ArXiv today.

    in reply to: J B Sidgwick #585006
    Jeremy Shears
    Participant

    Fascinating reading that obit and bio. There must be so much more to tell, tho!

    in reply to: Nova in Aries? #584992
    Jeremy Shears
    Participant

    This object is still around 13th mag and worth following:

    in reply to: J-BAA Electronic #584973
    Jeremy Shears
    Participant

    I have the printed Journal for a few reasons.

    1. I’m far more likely to read it. I have a mixture of other publications in either printed or electronic format. I am far more likely to read a printed edition. I tend to forget about a electronic publication. Or I might read a couple of articles, think I will continue another time, but don’t. It’s much easier for me to pickup and put down a printed edition, leaving it by my favourite chair.

    2. I find it difficult to take in detail when I read it from a screen; I also absorb more info in printed format.

    3. I much prefer the feel of a printed mag or book 

    4. Much of my day job is performed on screens. I look for opportunities not to use them when I can

    The big advantage of electronic is when I travel. I can read the Journal anywhere on my iPad. But aways have that choice as my non-electronic sub also gives access to the electronic Journal 

    in reply to: ER Uma and RZ Lmi: Observations requested. #584952
    Jeremy Shears
    Participant

    Looks like a busy December, Stewart!

    in reply to: CDA Award 2022 #584950
    Jeremy Shears
    Participant

    What a fascinating project. Wouldn’t mind enrolling myself!

    in reply to: Nova in Aries? #584946
    Jeremy Shears
    Participant

    Observations made last night ~ Nov 29.9 by Tamas Tordai (Hungary) show beautiful ~ 0.1 mg humps, varying between ~12.4-12.5 in V (AAVSO data)

    in reply to: Nova in Aries? #584945
    Jeremy Shears
    Participant

    Further info on this transient continues to roll in. Isogai et al. report that the spectrum of this object suggests it is a dwarf nova of the WZ Sge type. They also observed early superhump-like modulations that occur in this type of object. If confirmed this would be the WZ Sge-type dwarf nova having the largest outburst amplitude ever seen.

    in reply to: Nova in Aries? #584944
    Jeremy Shears
    Participant

    Available here.

    Notre you can change orientation, limiting mag etc by clicking the “Plot another chart” link.

    Comp star sequence here.

    in reply to: Nova in Aries? #584941
    Jeremy Shears
    Participant

    An ATel by Taguchi et al. (Tokyo U) reports a low res spectrum consistent with a nova, but a UGWZ dwarf nova classification cannot be ruled out at this stage.

    More observations needed!

    in reply to: Suggestions for CV stars in the Southern Hemisphere #584932
    Jeremy Shears
    Participant

    Stewart, you can interrogate the VSX database 

    You can ask it to return UGSS, or UGER, or whatever you fancy. You can select to get the results returNed sorted by Dec, which will help you to find southerly targets

    in reply to: V606 Vul #584907
    Jeremy Shears
    Participant

    Link not working Maxim. I think it’s a transitory one – please can you post the reference 

    in reply to: V606 Vul #584902
    Jeremy Shears
    Participant

    This recent paper considers the origin of this flaring phenomenon – it’s actually about another nova, but they generalise to all of these slow, dusty systems. However, they state that it’s still an open question  -and there may be multiple scenarios in different systems. They favour multiple episodes of mass ejection. They propose that the photosphere expands during a flare – the flares produce shocks which lead to high energy gamma-rays and dust production, others due to instabilities in the accretion disc around the white dwarf created by enhanced accretion stimulated by heating from the secondary star.

    The authors of that paper (which include amateurs) make plea for further studies of other novae, so it is good that you and others are following this nova.

    in reply to: Nova Cas 2021 #584891
    Jeremy Shears
    Participant

    This paper on ArXiv today on the light curve of the nova includes spectroscopy from BAA members: https://arxiv.org/abs/2111.02463

    in reply to: BAA AGM livestream #584834
    Jeremy Shears
    Participant

    Superb meeting. The BAA at its best. Many thanks to everyone involve!

    in reply to: BAA AGM livestream #584833
    Jeremy Shears
    Participant

    Nick – wanted to say that the presentation style is excellent – the way the speaker is shown, plus the slides. And the way the slide is expanded at times. Sound q very good too.

    Whilst it would be great to be there in person, it’s actually a really good experience watching remotely too.

    in reply to: BAA AGM livestream #584831
    Jeremy Shears
    Participant

    Thanks Nick – working well

    in reply to: LL And rare outburst #584829
    Jeremy Shears
    Participant

    Here is the light curve of the superoutburst until today (observations from the VSS database). No rebrightenings have been seen.

    in reply to: Recurrent Nova RS Oph #584794
    Jeremy Shears
    Participant

    An ATel published yesterday reports that flickering in the light curve of RS Oph ceased during September: https://www.astronomerstelegram.org/?read=14974

    This suggests that the recent nova eruption destroyed the accretion disc, as was found following the previous eruption. in that event,it reappeared after 240 days.

Viewing 20 posts - 181 through 200 (of 547 total)