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TRANSCRIPT
CHARACTERIZING THE COOLER KOIS
PLANETS AROUND MID M DWARFS
Benjamin Montet (Caltech/Harvard)K2 Science Conference
4 November 2015
@benmontet
THANKS TO COLLABORATORS!
Dan Foreman-Mackey (UW)David Hogg (NYU)John Johnson (Harvard)Tim Morton (Princeton)Yutong Shan (Harvard)Andrew Vandenburg (Harvard)And many others…
WE ALREADY UNDERSTAND PLANETS AROUND M DWARFS
WE ALREADY UNDERSTAND PLANETS AROUND M DWARFS
WE ALREADY UNDERSTAND PLANETS AROUND M DWARFS
WE ALREADY UNDERSTAND PLANETS AROUND M DWARFS
WE DON’T UNDERSTAND PLANETS AROUND M DWARFS
WE DON’T UNDERSTAND PLANETS AROUND M DWARFS
GiantsDwarfs
WE DON’T UNDERSTAND PLANETS AROUND M DWARFS
GiantsDwarfs
WE DON’T UNDERSTAND PLANETS AROUND M DWARFS
GiantsDwarfs
WE DON’T UNDERSTAND PLANETS AROUND M DWARFS
GiantsDwarfs
WE DON’T UNDERSTAND PLANETS AROUND M DWARFS
GiantsDwarfs
WE DON’T UNDERSTAND PLANETS AROUND M DWARFS
GiantsDwarfs
WE DON’T UNDERSTAND PLANETS AROUND M DWARFS
ABOUT 85% OF KEPLER’S M DWARFS ARE M0-M1 DWARFS
MOST STARS IN THE GALAXY ARE MID-M DWARFS
K2 IS PROBING THESE!
M DWARFS ARE NEARBY, APPROXIMATELY ISOTROPIC
M DWARFS ARE NEARBY, APPROXIMATELY ISOTROPIC
M DWARFS ARE NEARBY, APPROXIMATELY ISOTROPIC
K2
KEPLER OBSERVED 300 M2-8 DWARFS
K2 WILL OBSERVE 3,500 IN FIELDS 4 AND 5
ALONE
PLANETS AROUND M DWARFS
Montet et al. (2015b)
ConfirmedCandidate
False PositiveDFM et al. (2015)
PLANETS AROUND M DWARFS
ConfirmedCandidate
False PositiveMontet et al. (2015b)
DFM et al. (2015)
STELLAR CHARACTERIZATION
Statistical, with isochrones (Tim Morton, on github)
Data-driven, with TripleSpec, SpeX, and broadband photometry
PLANET VALIDATION
Statistical, with vespa (Tim Morton, on github)
Data-driven, with Keck/NIRC2, P200/PHARO,
archival imaging with POSS, SDSS
PLANET VALIDATION
K2-18b• 33 day period (from C1)
• 2.24±0.23 Earth-radius planet around an M2.8 dwarf
• Equilibrium temperature of 272±15 K
• GJ1214b analog with Earthlike insolation—useful for composition studies?
MID-M PLANET HOSTS IN C4
MID-M PLANET HOSTS IN C4
Two of these host stars have colors consistent
with M4
Only three such planetary systems in
Kepler!
WHERE ARE THE M DWARF PLANETS?
WHERE ARE THE M DWARF PLANETS?
Morton and Swift 2014
WHERE ARE THE M DWARF PLANETS?
• Strong falloff in expected planet yield with decreasing sensitivity
• Stars drawn from the same population in K2 and Kepler
• Stars are typically less massive, especially in C4/5
• Need to understand completeness well before we claim a lower occurrence
• Injections important, before any detrending processes!
WE DON’T ACTUALLY UNDERSTAND THE POPULATION OF PLANETS
AROUND M DWARFS
BUT K2 IS HELPING US LEARN
WHERE ARE THE M DWARF PLANETS?
• Strong falloff in expected planet yield with decreasing sensitivity
• Stars drawn from the same population in K2 and Kepler
• Stars are typically less massive, especially in C4/5
• Need to understand completeness well before we claim a lower occurrence
• Injections important, before any detrending processes!
MID-M PLANET HOSTS IN C5?