OJ287

Forums Variable Stars OJ287

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  • #612756
    Gary Poyner
    Participant

    I’ve just posted the following to BAAVSS-Alert group…

    Gary

    ————————————

    The predicted date for the flare in the BH candidate OJ+287 which was expected to occur in July/August (Solar Conjunction) has been revised to early October, as reported here…

    https://arxiv.org/abs/2209.08360
    (Refining the prediction for OJ 287 next impact flare arrival epoch. Valtonen et al)

    Mark Kidger comments…

    “Mauri Valtonen’s model had a new outburst due in July/August this year. Based on observations in 2020, Mauri was already suspecting strongly that the next outburst would be delayed a couple of months into the Autumn observational window. New calculations, just published, based on the well-observed 2005 outburst, have indicated that the outburst will, indeed, be delayed by about 2 months, with a predicted date of maximum on October 10th 2022 (in about 2 weeks), with an estimated error of +/-10 days.

    Early observations by Gary and from Japan show that OJ287 is in a very low state, which was expected, pre-outburst. However, if the model is correct, that should change quickly.

    OJ287 is rising rapidly at dawn and is observable in increasingly favourable conditions.”

    Both visual and CCD observations (BVRI or CV) are requested for the coming weeks in order to follow OJ through the flare (if it occurs) and beyond. Please report your data to the BAAVSS database and/or the AAVSO IDB in good time.

    #613066
    Gary Poyner
    Participant

    Those of you who have been monitoring OJ287 during the last few weeks will know that the ‘flare’ did not happen at the predicted date, and it doesn’t look like it will happen in the error margin either (Oct 20, see above). This looks like being a rare failure for the OJ team in their predictions for disk impacts/flares, and more information will be posted here when it becomes available.

    Thanks to those who have reported observations over the past few weeks, and those observers (and others of course) are asked to continue monitoring OJ287 to see what the next few weeks or months bring with it’s optical behaviour.

    Please report your data to the VSS in the usual way.

    Gary

    #619619
    Gary Poyner
    Participant

    The binary black hole OJ287 has been rising in brightness slowly since leaving solar conjunction in late Summer, and is currently at its brightest level since May 2020 at 14.29V (Oct 13).

    What might happen next? Please monitor regularly if you are able, and submit your data to the VSS database at the earliest possible time.

    OJ287 lies in Cancer at 08 54 48.88 +20 06 30.6 (2000.0) and there are charts on the BAAVSS website.

    Gary

    • This reply was modified 1 year, 2 months ago by Gary Poyner.
    #619630
    Mr Ian David Sharp
    Participant

    Thanks for the info Gary,

    I managed a decent set of R, V and B last night from Spain. V mag was coming out at around 14.6 with R at about 14.2.

    All uploaded into the dB.

    Cheers
    Ian.

    #619636
    Gary Poyner
    Participant

    Thanks Ian,

    OJ was guaranteed to fade once I put an alert out – sods law! I had it 14.7 visual this morning, and 14.6C a couple of hours earlier with SLOOH.

    Keep at it if you can, as sometimes these flares can vary a bit.

    Gary

    #622063
    Stewart John Bean
    Participant

    Gary, Do you know when the next big flare ( smaller black hole punches through the accretion disc) is supposed to be? I cannot work it out from the papers. Stewart

    #622066
    Gary Poyner
    Participant

    Stewart,

    I have two predictions…

    MOMO (Multiwavelength Observations and Modelling of OJ287) 2026-2028

    Mauri Valtonen – May 30, 2031

    Disappointment looms for somebody!

    Gary

    #622067
    Stewart John Bean
    Participant

    Ah yes. the two competing models. Thanks

    #626770
    Mr Ian David Sharp
    Participant

    Hi all,

    There’s a small brightening of OJ 287 going on. Not sure if it will be significant.

    Cheers
    Ian.

    Attachments:
    #626772
    Gary Poyner
    Participant

    Yes, it is brightening – and about time too.

    Martin Mobberley and I have been working with Mark Kidger on OJ for a long time now (along with several Spanish observers). I’m sure he won’t mind me uploading his most recent plot from a few minutes ago.

    We try not to get too excited when OJ does this, but it has been in a low state for a while now, so anything above mag 16 is worth mentioning.

    Gary

    Attachments:
    #626786
    Mr Ian David Sharp
    Participant

    Thanks Gary,

    I’ve uploaded my R, V and B results from last night – it seems to have steadied. I’ll continue to observe it when I can and my data is always in the BAA database if it’s needed.

    Cheers
    Ian.

    Attachments:
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