EPIC248847494 ,A (possibly) record-breaking exoplanet found with a ten-year orbit
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by firejuggler
Here is the paper https://arxiv.org/pdf/1806.08757.pdf
and the abstractContext.
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 discoveredNow for the question : Have ever encountered something similar yet?
Posted
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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
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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
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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
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by squirreldude
is c12 part of nasa? in nasa archives?
Posted
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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