J/AJ/169/109 Radial velocities of TOI-1266 from MAROON-X (Tyler+, 2025)
Revised masses for low-density planets orbiting the disordered M-dwarf system
TOI-1266.
Tyler D., Petigura E.A., Rogers J., Lubin J., Seifhart A., Bean J.L.,
Brady M., Luque R.
<Astron. J., 169, 109 (2025)>
=2025AJ....169..109T 2025AJ....169..109T
ADC_Keywords: Exoplanets; Radial velocities; Stars, M-type; Stars, dwarfs;
Spectroscopy; Optical
Keywords: Exoplanet evolution ; Exoplanet astronomy ;
Exoplanet detection methods ; Radial velocity ; Exoplanet systems ;
Exoplanet atmospheric composition
Abstract:
We present an analysis of 126 new radial velocity measurements from
the MAROON-X spectrograph to investigate the TOI-1266 system, which
hosts two known transiting sub-Neptunes at 10.8 and 18.8 days. We
integrated our measurements with existing HARPS-N measurements for
this system and derived revised masses for TOI-1266 b and c of
Mb=4.09±0.45M⊕ and Mc=2.64±0.52M⊕,
respectively. The Keplerian fit from the combined datasets enabled an
∼35% and ∼41% improvement in mass precision for planet b and c,
respectively, compared to the previously published values. With bulk
densities of ρb=1.25±0.21g/cm3 and ρc=1.51±0.39g/cm,
the planets are among the lowest density sub-Neptunes orbiting an M
dwarf. They are both consistent with rocky cores surrounded by
hydrogen helium envelopes. TOI-1266 c may also be consistent with a
water-rich composition, but we disfavor that interpretation from an
Occam's razor perspective.
Description:
We obtained 63 observations for TOI-1266 using the MAROON-X (M-dwarf
Advanced Radial velocity Observer Of Neighboring eXoplanets)
spectrograph mounted on the 8.1 m Gemini North telescope in Hawaii,
US, from 2022 March 24 UT to 2023 July 11 UT (program IDs:
GN-2022A-Q-103, GN-2023A-Q-202). It uses both red (640-920nm) and blue
(490-720nm) arms which yield two RV measurements per observation.
Our observational campaign spanned two observing seasons to maximize
coverage and temporal resolution. Our sampling was tailored to the
specific timing blocks during which MAROON-X was on sky. This resulted
in four separate high-cadence runs spanning from 2022A to 2023A. In
total, we collected 126 RV measurements, with the data split evenly
between MAROON-X's red and blue arms.
Objects:
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RA (2000) DE Designation(s)
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13 11 59.56 +65 50 01.7 TOI-1266 = 2MASS J13115955+6550017
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File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
fig2.dat 30 126 MAROON-X radial velocities of TOI-1266 (data behind
Figure 2)
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See also:
J/MNRAS/422/2024 : X-ray-age relation & exoplanet evaporation (Jackson+, 2012)
J/ApJ/807/45 : Potentially habitable planets orbit. M dwarfs (Dressing+, 2015)
J/AJ/154/109 : California-Kepler Surv. (CKS). III. Planet radii (Fulton+, 2017)
J/AJ/159/211 : Exoplanets parameters from Kepler and K2 (Cloutier+, 2020)
J/MNRAS/491/5287 : Exoplanet evaporation in multitransiting syst. (Owen+, 2020)
J/AJ/160/259 : HPF RVs and TESS photometry of TOI-1266 (Stefansson+, 2020)
J/AJ/161/36 : 117 exoplanets in habitable zone with Kepler DR25 (Bryson+, 2021)
J/AJ/162/55 : 65 Transit-timing variation planets properties (Yee+, 2021)
J/other/Sci/377.1211 : RV and LC of 8 M dwarf stars with planets (Luque+, 2022)
J/AJ/163/179 : The California-Kepler Survey. X. (Petigura+, 2022)
J/AJ/163/168 : Photometry and radial velocity of LTT 1445A (Winters+, 2022)
J/AJ/165/167 : HARPS-N radial velocities of TOI-1695 (Cherubim+, 2023)
Byte-by-byte Description of file: fig2.dat
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Bytes Format Units Label Explanations
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1- 14 F14.6 d BJD [2459660/2460140] Barycentric Julian Date
16- 20 F5.2 m/s RVel [-7.32/7.52] Radial velocity
22- 25 F4.2 m/s e_RVel [0.64/2.8] Uncertainty in RVel
27- 30 A4 --- Arm Spectrograph arm identifier (1)
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Note (1): Arms of the MAROON-X (M-dwarf Advanced Radial velocity Observer Of
Neighboring eXoplanets) spectrograph, mounted on the 8.1m Gemini
North telescope in Hawaii, US, as follows:
Blue = 490-720nm (63 occurrences)
Red = 640-920nm (63 occurrences)
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History:
From electronic version of the journal
(End) Prepared by [AAS], Robin Leichtnam [CDS] 04-Dec-2025