Planet Hunters Talk

EPIC248847494 ,A (possibly) record-breaking exoplanet found with a ten-year orbit

  • firejuggler by firejuggler

    Here is the paper https://arxiv.org/pdf/1806.08757.pdf
    and the abstract

    Context.
    We present the transit and follow-up of a single transit event from Campaign 14 of
    K2,
    EPIC248847494b, which has a
    duration of 54 hours and a 0.18%-depth.

    Aims.
    Using photometric tools and conducting radial velocity follow-up, we vet and characterise this very strong candidate.

    Methods.
    Due to a long, unknown period, standard follow-up methods need to be adapted. The transit is fitted using
    Namaste
    , and
    the radial velocity slope measured and compared to a grid of planet-like orbits with varying masses and periods. These utilised stellar
    parameters measured from spectra and the distance as measured by Gaia.

    Results.
    Orbiting around a sub-giant star with a radius of 2.70
    ±
    0.12R
    Sol
    , the planet has a radius of 1.11
    +
    0
    .
    07

    0
    .
    07
    R
    Jup
    and a period of
    3650
    +
    1280

    1130
    days. The radial velocity measurements constrain the mass to be less than 13M
    Jup
    , which implies a planetary-like object.
    Conclusions.
    We have found a planet at 4.5 AU from a single transit event. After a full radial velocity follow-up campaign, if
    confirmed, it will be the longest-period transiting planet discovered

    Now for the question : Have ever encountered something similar yet?

    Posted

  • squirreldude by squirreldude

    so this isn't some dwarf planet but confirmed based on a certain measurement scale if I"m understanding this correctly? I was looking at this, but I don't know if these are confirmed orbits - http://exoplanet.hanno-rein.de/planet/HR 8799 c/ , either HR 8799c, HR 8799d, or HR 8799e respectively.

    Posted

  • firejuggler by firejuggler

    No this is not a "dwarf" planet. as said in the abstract, it is a planet hovering around 1.1 time the radius of jupiter. around a star 2.7 time the radius of our own sun.

    Posted

  • ajamyajax by ajamyajax in response to firejuggler's comment.

    We've seen plenty of long duration transits, so might have a few in that category. For example, see what you think of 246028803 in C12. Some number could be stellar transits though so more work is needed.

    Posted

  • squirreldude by squirreldude

    is c12 part of nasa? in nasa archives?

    Posted

  • ajamyajax by ajamyajax

    Yes, from NASA Kepler Campaign 12. And you can search by K2 ID here, or at the NASA related archive, and the internet too (especially for other known exoplanet systems).

    http://archive.stsci.edu/k2/data_search/search.php

    Posted