Planet Hunters Talk

Brown dwarfs and more from APOGEE data (article)

  • ajamyajax by ajamyajax

    "An oasis in the brown dwarf desert"

    Astronomers report a wellspring of new brown dwarf stellar companions, throwing cold water on the entire idea of the “brown dwarf desert,” the previously mystifying lack of these sub-stellar objects around stars.

    http://www.astronomy.com/news/2016/04/an-oasis-in-the-brown-dwarf-desert

    By Sloan Digital Sky Survey Press Office

    It turns out that this tightly controlled environment makes it possible to use the APOGEE instrument to measure Doppler shifts reliably over the course of months or years, a feat not achievable by many other spectrographs...

    “Even with the first data obtained a few years ago, it was clear that we could use APOGEE to detect the motions of planet-sized objects around our target stars,” said David Nidever of the University of Arizona, Tucson. “It definitely opened our eyes to the possibilities of doing a more systematic search for planets and brown dwarfs.”

    ...

    Apache Point Observatory Galactic Evolution Experiment (APOGEE)

    DR12 includes data from ~14,000 stars in Kepler/CoRoT fields...

    http://www.sdss.org/dr12/irspec/

    An expanded discussion of the Kepler field targeting can be found in Pinsoneault et al. 2014.

    "The APOKASC Catalog: An Asteroseismic and Spectroscopic Joint Survey of Targets in the Kepler Fields"

    http://adsabs.harvard.edu/abs/2014ApJS..215...19P

    Posted

  • ajamyajax by ajamyajax

    Looks like we can make use of APOGEE data in a general way where it is available with the VHELIO header info in the FITS files. From this paper's EB KIC 01571511 example in Fig 3:

    "For the given Kepler period and epoch of transit, it is clear even with just three APOGEE RVs that the object is not a planet, because the change in RV over a short fraction of the orbit is much greater (∼ 10 km s−1) than expected for a planetary mass."

    "We also present the first results from our APOGEE-Kepler KOI campaign, using the (since confirmed) exoplanet host KIC 6448890 to test our long-term RV precision..."

    KIC 1571511 vhelio min,max,mean,stdmean% -26.0346 -18.5818 -22.790133 ~13.68%

    KIC 6448890 (shown) vhelio min,max,mean,stdmean% -54.5202 -54.0371 -54.2798074074 ~0.22%

    The paper's authors also made an adjustment to this data which I haven't figured out yet, as shown in the chart. Maybe for the Earth's own RV from the Moon(?) Anybody know?... I probably just need to read some more. But the data is still useful as-is.

    Here is the paper:

    "THE APOGEE SPECTROSCOPIC SURVEY OF KEPLER PLANET HOSTS: FEASIBILITY, EFFICIENCY, AND FIRST RESULTS"

    http://arxiv.org/pdf/1502.05035v1.pdf

    APO1

    Update: just related news that might interest:

    "New tool refines exoplanet search"

    http://phys.org/news/2016-04-tool-refines-exoplanet.html

    Posted

  • ajamyajax by ajamyajax

    "Can garnet planets be habitable?"

    http://phys.org/news/2017-01-garnet-planets-habitable.html

    "A fraction of the almost 200,000 stars surveyed by APOGEE overlap with the sample of stars targeted by the NASA Kepler mission, which was designed to find potentially Earth-like planets. The work presented today focuses on ninety Kepler stars that show evidence of hosting rocky planets, and which have also been surveyed by APOGEE."

    Posted