Jeremy Shears

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Viewing 20 posts - 301 through 320 (of 656 total)
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  • 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.

    in reply to: LL And rare outburst #584767
    Jeremy Shears
    Participant

    LL And has been in outburst for nearly a month, but it is now fading (Gary Poyner had at mag 16.7 last night, Oct 9.965).

    However, some rarely outbursting dwarf novae sometimes exhibit rebrightenings (sometimes referred to as echo outbursts). These can occur a few days after the outburst is apparently over. And there can be more than one rebrightening.

    Therefore please continue to observe this star. Nightly snapshot observations over the next week or two would be helpful.

    in reply to: Nova Cas 2021 #584730
    Jeremy Shears
    Participant

    The nova that keeps on giving!

    in reply to: Recurrent Nova RS Oph #584728
    Jeremy Shears
    Participant

    Declining, but not back at quiescence (minimum) yet.

    in reply to: LL And rare outburst #584727
    Jeremy Shears
    Participant

    LL And is currently around 14th mag and still in the plateau phase of its superoutburst. It is showing small, but elegant, superhumps. Further observations, including t/series photometry welcome.

    in reply to: AF Cygni #584726
    Jeremy Shears
    Participant

    Hello Darryl,

    AF Cyg is a semi regular star with a period of around 3 months. As such, it doesn’t undergo outbursts. Looking at its light curve in the VSS database, it appears to be approaching maximum. Some maxima are brighter than others. It’s brightness range is listed as 6.2 – 7.9 V, although the more usual range is 6.7 – 7.7. One maximum in 2019 reached mag 6.2

    Glad to see you are observing this star and contributing your obs to the VSS database.

    in reply to: Recurrent Nova RS Oph #584725
    Jeremy Shears
    Participant
    in reply to: Tatton Park meteorite #584685
    Jeremy Shears
    Participant

    indeed you are correct: it’s a different Mike Peel, Denis. I’ve been in touch with the MP who took the pic of the meteorite, although he has no further light to shed on the exhibit.

    in reply to: Tatton Park meteorite #584672
    Jeremy Shears
    Participant

    Many thanks to everyone who replied.
    Certainly worth having a look at the Egerton exhibition if anyone is visiting Tatton Park. Maurice Egerton was a fascinating character, interested in so many different things. I asked the curator if she had seen anything about an interest in astronomy or telescopes during her PhD research, but she has not come across anything.

    Certainly a place to visit for a grand day out.

    in reply to: Nova Cas 2021 #584645
    Jeremy Shears
    Participant

    This nova is still showing lots of interesting activity. And it’s still 8th mag

    in reply to: Recurrent Nova RS Oph #584644
    Jeremy Shears
    Participant

    Please continue to observe RS Oph – the eruption continues:

    in reply to: Recurrent Nova RS Oph #584642
    Jeremy Shears
    Participant

    Munari and Valisa have published an article on “The 2021 outburst of RS Oph. A pictorial atlas of the spectroscopic evolution: the first 18 days” on ArXiv today.

Viewing 20 posts - 301 through 320 (of 656 total)