Planet Hunters Talk

Likely Transiting Exocomets Detected by Kepler

  • Tom128 by Tom128

    Two likely exocomets found within the Kepler main field:

    https://arxiv.org/abs/1708.06069

    Posted

  • Artman40 by Artman40

    By the way, are there individual exocomets discovered so far?

    Posted

  • ajamyajax by ajamyajax in response to Tom128's comment.

    Tom, nice spotting and comprehensive analysis by all. I especially enjoyed the "exhaustive visual search of the entire Kepler photometric data set" part. Whew! I'm exhausted just thinking about that. 😃

    Congrats!!!

    Posted

  • ajamyajax by ajamyajax in response to Artman40's comment.

    Pls see this link and also consider KIC 8462852:

    https://en.wikipedia.org/wiki/Exocomet

    Posted

  • Tom128 by Tom128

    Thanks ajamyajax, it took me five months to visually survey the complete DR25 Kepler prime-field of approximately 200k stars using LcTools and only two stars showed exocomet profiles. The next step to validate the finds is using spectrographic follow up observations. That will depend upon community interest as scope time is limited for the assets needed to do this such as Keck or LBT.

    Posted

  • Tom128 by Tom128

    Here is a blog article that talks more about the visual survey of the entire Kepler prime-field and how the exocomets were identified and analyzed.

    http://keplerlightcurves.blogspot.com/2017/08/likely-transiting-exocomets-detected-by.html

    Posted

  • ajamyajax by ajamyajax in response to Tom128's comment.

    Impressive write-up also. And I know there are solar system comets in the K2 data, observed on purpose. Just wondered if you studied those yet and looked for any possible new comets in the K2 data, be they sso's or exo objects?

    (Just search for 'comet' here and those targeted will be listed)

    https://keplergo.arc.nasa.gov/k2-approved-programs.html

    Posted

  • Tom128 by Tom128

    Hi ajamyajax,

    I think K2 is essentially unsurveyed for exocomets and well worth going over the data. Two issues with K2 are one, visual quality of the pipeline data and two, short observation period as well as narrow FOV of selected stars. The exocomet profile requires sufficient data points like what was found in the Kepler prime- field. Many of the LC events in K2 have few data points. With that said, I agree there must be a some good exocomets in the K2 campaigns, though the events appear to be rare.

    Posted

  • ajamyajax by ajamyajax in response to Tom128's comment.

    Ok Tom, makes sense. Will keep an eye open for possible single transits that at least partially resemble the shape of your exocomet transits in this data.

    ...

    Re 247450113 from Ivan's list: possible exocomet, or perhaps more likely a possible Jupiter class planet candidate with the 1.86 R_Sun value from Huber et al.
    If not a glitch of course.

    s1=3003.52 p1=? d1=0.55 (13.2 hours +/-)

    Semi-Major Axis a (A.U.) = 0.34

    Radius (R_Sun) = 1.863

    Mass (M_Sun)= 1.145

    Period ~= 67.732 days

    Duration ~= 13.2014 hours

    Duration in BKJD ~= 0.5501 days

    EPIC, 2MASS, J mag, H mag, K mag, J - H, H - K, (J-H spectral type, stellar mass est) (H-K spectral type, stellar mass est)

    247450113 , 2MASS J04530154+2148133 , 12.484 , 12.113 , 11.972 , 0.371 , 0.141 , ('G9V', 0.91) , ('K5V',0.75)

    From NEA, K2 Targets within search area:

    EPIC Number RA [decimal degrees] Dec [decimal degrees] Distance [arc sec] Kepler-band [mag] Campaign Number

    247450113 73.2564 21.8038 0.01 14.047 13

    247452715 73.2717 21.824 89.08 14.421 13

    epic_number,tm_name,ra,dec,Huber_ExoFOP_teff,Huber_ExoFOP_rad,Huber_ExoFOP_mass,k2_kepmag,k2_pmra,k2_pmdec,Huber_ExoFOP_dist,k2_propid

    247450113,2MASS J04530154+2148133,73.256398,21.803755,5886,1.863,1.145,14.047,13.700,-5.000,9.793e+02,GO13050_LC

    Aliases

    WISE J045301.55+214813.4

    Program GO13050_LC:

    GO13050 Burke K2 Exoplanet Ecliptic Survey - KEES

    https://keplergo.arc.nasa.gov/data/k2-programs/GO13050.txt

    T1

    Posted

  • Tom128 by Tom128

    This one is likely an eclipse or single planet transit barring a systematic glitch. Here is an LcTools pic of a single comet candidate (from paper) with obvious trailing tail and short duration. What would be a good smoking gun is several aperiodic transits with trailing tails.

    https://drive.google.com/open?id=0B_XSdrQ8n1sfS0hBd1V2eW50dnRLY0VpRWZaVDlfcVhmNi13

    Posted

  • ajamyajax by ajamyajax in response to Tom128's comment.

    Roger that. Will keep looking.

    Posted

  • ajamyajax by ajamyajax

    Well, this is something new and different!

    "Hubble discovers a unique type of object in the Solar System"

    https://phys.org/news/2017-09-hubble-unique-solar.html

    "HUBBLE AND KECK TELESCOPE OBSERVATIONS OF ACTIVE ASTEROID 288P/300163 (2006 VW139)"

    http://www2.ess.ucla.edu/~jewitt/papers/2016/AJW16.pdf

    "A binary main belt comet"

    http://www.spacetelescope.org/static/archives/releases/science_papers/heic1715/heic1715a.pdf

    And I wonder if 288P/300163 ever in Kepler's field of view?

    Posted

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

    K2ephem 1.5.0 now shows us when and where to look in the K2 data for comets...

    Recent update comment "Automatically add the CAP directory for comets"

    From https://github.com/KeplerGO/K2ephem

    2006 VW139/288P...

    K2 ephemeris for 2006 VW139 from JPL/Horizons...

    Object '2006 VW139' is visible in C16 (mag 21.1..22.0; 3.4..33.0"/h; ra 121.785..128.766; dec 20.567..21.700).

    Object '2006 VW139' is visible in C18 (mag 21.8..22.6; 1.2..36.4"/h; ra 113.925..127.201; dec 21.373..24.373).

    (same) K2 ephemeris for 300163 from JPL/Horizons...

    Object '300163' is visible in C16 (mag 21.1..22.0; 3.4..33.0"/h; ra 121.785..128.766; dec 20.567..21.700).

    Object '300163' is visible in C18 (mag 21.8..22.6; 1.2..36.4"/h; ra 113.925..127.201; dec 21.373..24.373).

    Posted

  • ajamyajax by ajamyajax

    "Citizen scientist spots comet tails streaking past distant star"

    https://phys.org/news/2017-10-citizen-scientist-comet-tails-streaking.html

    "Citizen scientist Thomas Jacobs was the first to spot tell-tale signs that a comet was orbiting a distant star monitored by the Kepler Space Observatory..."

    Posted

  • ProtoJeb21 by ProtoJeb21

    @Tom128 a "little" late, but congratulations! It's always great to see citizen scientists making amazing discoveries like this. I also need your opinion on the weird behavior of the star EPIC 215938010. Short, periodic transit-like events appear for half the lightcurve, then disappear after BKJD 2514.448285. The transit events have an odd behavior of randomly alternating between large and small dips. The folded transit is also quite bizarre, with two small troughs near the beginning and end with a slight peak in the middle. Viewed with 10 SIgnal Durations, the peak and troughs disappear, but two "legs" of data points still remain. I'm wondering if this is reminiscent of the exocomet candidates you found, or if it may be something else entirely.



    (Notice: this was all done using Everest2 data and Al Schmitt's LcViewer)

    Posted

  • Tom128 by Tom128

    Hi ProtoJeb21,

    The main issue with identifying exocomets is finding events with enough data points and comet-like profile to convince veteran astronomers such as Saul Rappaport that they are indeed likely candidates. That is why the exocomet paper focused primarily on the very three larger drops in the paper and added in the three smaller events as maybes. K2, in general, does not offer enough data points in the events to know for sure they are really asymmetric. I keep looking for the perfect event with enough data points and asymetric comet profile. No go thus far.

    Posted

  • Tom128 by Tom128

    A third comet system was discovered in the Kepler prime-field using an automated search program. https://arxiv.org/pdf/1811.03102.pdf

    https://arxiv.org/pdf/1811.03102.pdfenter image description here

    Posted