J/AJ/165/113 KPIC radial velocity follow up of HR 7672 B (Ruffio+, 2023)
Detecting Exomoons from Radial Velocity Measurements of Self-luminous Planets:
Application to Observations of HR 7672 B and Future Prospects.
Ruffio J.-B., Horstman K., Mawet D., Rosenthal L.J., Batygin K.,
Wang J.J., Millar-Blanchaer M., Wang Ji, Fulton B.J., Konopacky Q.M.,
Agrawal S., Hirsch L.A., Howard A.W., Blunt S., Nielsen E., Baker A.,
Bartos R., Bond C.Z., Calvin B., Cetre S., Delorme J.-R., Doppmann G.,
Echeverri D., Finnerty L., Fitzgerald M.P., Jovanovic N., Lopez R.,
Martin E.C., Morris E., Pezzato J., Ruane G., Sappey B., Schofield T.,
Skemer A., Venenciano T., Wallace J.K., Wallack N.L., Wizinowich P.,
Xuan J.W.
<Astron. J., 165, 113 (2023)>
=2023AJ....165..113R 2023AJ....165..113R
ADC_Keywords: Minor planets; Exoplanets; Stars, brown dwarf; Spectra, infrared;
Radial velocities
Keywords: Natural satellites (Extrasolar) ; Direct imaging ; Radial
velocity ; Exoplanet detection methods
Abstract:
The detection of satellites around extrasolar planets, so called
exomoons, remains a largely unexplored territory. In this work, we
study the potential of detecting these elusive objects from radial
velocity monitoring of self-luminous, directly imaged planets. This
technique is now possible thanks to the development of dedicated
instruments combining the power of high-resolution spectroscopy and
high-contrast imaging. First, we demonstrate a sensitivity to
satellites with a mass ratio of 1%-4% at separations similar to the
Galilean moons from observations of a brown-dwarf companion (HR7672B;
Kmag=13; 0.7" separation) with the Keck Planet Imager and
Characterizer (KPIC, R∼35000 in the K band) at the W.M.Keck
Observatory. Current instrumentation is therefore already sensitive to
large unresolved satellites that could be forming from gravitational
instability akin to binary star formation. Using end-to-end
simulations, we then estimate that future instruments such as the
Multi-Object Diffraction-limited High-resolution Infrared
Spectrograph, planned for the Thirty Meter Telescope, should be
sensitive to satellites with mass ratios of ∼10e-4. Such small moons
would likely form in a circumplanetary disk similar to the Jovian
satellites in the solar system. Looking for the Rossiter-McLaughlin
effect could also be an interesting pathway to detecting the smallest
moons on short orbital periods. Future exomoon discoveries will allow
precise mass measurements of the substellar companions that they orbit
and provide key insight into the formation of exoplanets. They would
also help constrain the population of habitable Earth-sized moons
orbiting gas giants in the habitable zone of their stars.
Description:
The brown-dwarf companion HR7672B was observed three times in 2020 and
then for a full night on 2021 July 4 with Keck Planet Imager and
Characterizer (KPIC) (R∼35000) in the K-band (1.9-2.4µm).
Objects:
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RA (2000) DE Designation(s)
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20 04 06.20 +17 04 13.0 HR 7672 B = * 15 Sge B
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File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
fig2.dat 41 240 Measured radial velocities of HR 7672 B with KPIC
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See also:
II/246 : 2MASS All-Sky Catalog of Point Sources (Cutri+ 2003)
J/A+A/463/671 : Rotational velocities of A-type stars. III. (Royer+, 2007)
J/ApJ/834/17 : Mass & radius of planets, moons, low mass stars (Chen+, 2017)
J/AJ/153/21 : Abundances in local region. II. F, G, & K dwarfs (Luck+, 2017)
J/ApJS/257/45 : BDKP V. Radial & rot. velocities of M, L, T dwarfs (Hsu+, 2021)
J/AJ/162/290 : OSIRIS Kband spectra of planets HR8799b, c, & d (Ruffio+, 2021)
J/ApJ/922/L2 : Limits on binary planets in HR 8799b, c & d (Vanderburg+, 2021)
J/AJ/164/143 : Spectroscopy of HR8799 planets with SCExAO/CHARIS (Wang+, 2022)
Byte-by-byte Description of file: fig2.dat
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Bytes Format Units Label Explanations
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1- 12 F12.6 d MJD [59008/59400] Modified Julian Date of the
observation; JD-2400000.5
14- 22 F9.2 m/s RVel [-14770/20513] Measured radial velocity
24- 31 F8.2 m/s e_RVel [1603/40333] Uncertainty in RVel
33- 41 A9 --- Label KPIC science fiber & NIRSPEC order information
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History:
From electronic version of the journal
(End) Prepared by [AAS], Coralie Fix [CDS], 20-Jun-2023