J/AJ/163/156 THYME. VI. TOI-1227 radial velocity (Mann+, 2022)
TESS Hunt for Young and Maturing Exoplanets (THYME).
VI. An 11Myr Giant Planet Transiting a Very-low-mass Star in Lower
Centaurus Crux.
Mann A.W., Wood M.L., Schmidt S.P., Barber M.G., Owen J.E.,
Tofflemire B.M., Newton E.R., Mamajek E.E., Bush J.L., Mace G.N.,
Kraus A.L., Thao P.C., Vanderburg A., Llama J., Johns-krull C.M., Prato L.,
Stahl A.G., Tang S.-Y., Fields M.J., Collins K.A., Collins K.I., Gan T.,
Jensen E.L.N., Kamler J., Schwarz R.P., Furlan E., Gnilka C.L.,
Howell S.B., Lester K.V., Owens D.A., Suarez O., Mekarnia D., Guillot T.,
Abe L., Triaud A.H.M.J., Johnson M.C., Milburn R.P., Rizzuto A.C.,
Quinn S.N., Kerr R., Ricker G.R., Vanderspek R., Latham D.W., Seager S.,
Winn J.N., Jenkins J.M., Guerrero N.M., Shporer A., Schlieder J.E.,
Mclean B., Wohler B.
<Astron. J., 163, 156-156 (2022)>
=2022AJ....163..156M 2022AJ....163..156M (SIMBAD/NED BibCode)
ADC_Keywords: Stars, pre-main sequence; Exoplanets; Spectra, optical;
Spectra, infrared; Radial velocities
Keywords: Pre-main sequence stars; Transits; Exoplanet evolution
Exoplanet formation; Stellar associations; Stellar ages
OB associations; Time domain astronomy; Time series analysis
Late-type stars; Low mass stars
Abstract:
Mature super-Earths and sub-Neptunes are predicted to be ∼Jovian
radius when younger than 10Myr. Thus, we expect to find 5-15 R⊕
planets around young stars even if their older counterparts harbor
none. We report the discovery and validation of TOI1227b, a
0.85±0.05R J (9.5R⊕) planet transiting a very-low-mass
star (0.170±0.015M☉) every 27.4days. TOI 1227's kinematics and
strong lithium absorption confirm that it is a member of a previously
discovered subgroup in the Lower Centaurus Crux OB association, which
we designate the Musca group. We derive an age of 11±2Myr for
Musca, based on lithium, rotation, and the color-magnitude diagram of
Musca members. The TESS data and ground-based follow-up show a deep
(2.5%) transit. We use multiwavelength transit observations and radial
velocities from the IGRINS spectrograph to validate the signal as
planetary in nature, and we obtain an upper limit on the planet mass
of ∼0.5M J. Because such large planets are exceptionally rare around
mature low-mass stars, we suggest that TOI1227b is still contracting
and will eventually turn into one of the more common <5R⊕
planets.
Description:
We observed TOI-1227 with the Southern African Large Telescope High
Resolution Spectrograph (HRS/SALT) on six nights (2020 May 08 to 2020
June 17). On each of the six visits, we obtained three back-to-back
exposures. We used the high-resolution mode with an integration time
of 800s per exposure. The resulting spectral resolution was R∼46000.
We observed TOI-1227 a total of 11 times from 2020 December 31 to 2021
April 24 with the Immersion Grating Infrared Spectrometer (IGRINS)
while on the Gemini-South observatory (program ID GS-2020B-FT-101).
IGRINS uses a silicon immersion grating to achieve high resolving
power (R∼45000) and simultaneous coverage of both H and K bands
(1.48-2.48µm) on two separate Hawaii-2RG detectors.
Objects:
---------------------------------------------------------
RA (2000) DE Designation(s) (Period)
---------------------------------------------------------
12 27 04.31 -72 27 06.5 TOI-1227 = TOI-1227 (P=1.65d)
---------------------------------------------------------
File Summary:
--------------------------------------------------------------------------------
FileName Lrecl Records Explanations
--------------------------------------------------------------------------------
ReadMe 80 . This file
table2.dat 29 17 Radial velocity measurements of TOI 1227
table5.dat 83 108 Friends of TOI 1227
--------------------------------------------------------------------------------
See also:
IV/38 : TESS Input Catalog - v8.0 (TIC-8) (Stassun+, 2019)
J/A+A/551/A46 : Compiled photometry Cham I & II members (Lopez Marti+, 2013)
J/MNRAS/435/1325 : Membership of the η Cha association (Murphy+, 2013)
J/ApJ/788/81 : BANYAN III. RVel and rotation of low-mass stars (Malo+, 2014)
J/A+A/573/A126 : VLT/NaCo Large program I. Sample (Desidera+, 2015)
J/AJ/157/234 : ACRONYM. III. Candidate low-mass stars (Schneider+, 2019)
J/AJ/161/65 : THYME. IV. 3 Exoplanets around TOI-451 B (Newton+, 2021)
J/AJ/161/171 : THYME. V. Discovering stellar association (Tofflemire+, 2021)
Byte-by-byte Description of file: table2.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 9 F9.4 d JD [8978/9330] Observation date, JD-2450000
11- 16 F6.3 km/s RVel [11.3/14.4] Radial Velocity
18- 22 F5.3 km/s e_RVel [0.03/0.5] Uncertainty in RVel (1)
24- 29 A6 --- Inst Instrument; HRS or IGRINS
--------------------------------------------------------------------------------
Note (1): IGRINS velocity errors are relative; the error on systemic
velocity of TOI1227 is 13.3±0.3km/s and is dominated by the
zero-point calibration. HRS velocities are absolute and include the
zero-point calibration.
--------------------------------------------------------------------------------
Byte-by-byte Description of file: table5.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 9 I9 --- TIC TESS input catalog identifier
11- 19 F9.5 deg RAdeg [167/204] Gaia EDR3 Right Ascension (ICRS at
Epoch 2016.0)
21- 29 F9.5 deg DEdeg [-78/-67] Gaia EDR3 Declination (ICRS at Epoch
2016.0)
31- 35 F5.2 km/s RVel [3.03/34.1]? Radial Velocity
37- 41 F5.2 km/s e_RVel [0.1/20]? Uncertainty in RVel
43- 56 A14 --- r_RVel Reference/Source for RVel (1)
58- 60 I3 0.1pm EWLi [23/598]? Equivalent width, Li, (mA)
62- 68 A7 --- r_EWLi Reference/Source for EWLi (2)
70- 74 F5.2 d Prot [0.3/24.6] Rotational period
76- 77 A2 --- q_Prot [Q0123] Rotational period Quality (3)
79- 79 A1 --- CMG Y=star is in Crux Moving Group,
Goldman+, 2018, J/ApJ/868/32
81- 81 A1 --- SpyGlass SpyGlass, Kerr+, 2021ApJ...917...23K 2021ApJ...917...23K
83- 83 A1 --- FF FriendFinder, Tofflemire+, 2021, J/AJ/161/171
--------------------------------------------------------------------------------
Note (1): Sources for RVel as follows:
Desidera2015 = Desidera+, 2015, J/A+A/573/A126
IGRINS = IGRINS/Gemini-S, this work;
Kharchenko2007 = Kharchenko+, 2007 J/AN/328/889
LopezMarti2013 = Lopez Marti+, 2013, J/A+A/551/A46
Malo2014 = Malo+, 2014, J/ApJ/788/81
Murphy2013 = Murphy+, 2013, J/MNRAS/435/1325
RAVEDR5 = Kunder+, 2017, III/379
Schneider2019 = Schneider+, 2019, J/AJ/157/234
Torres2006 = Torres+, 2006, J/A+A/460/695
GaiaDR2 = Katz+, 2019A&A...622A.205K 2019A&A...622A.205K
Note (2): Sources for EWLi as follows:
ESO = Spectra taken from the European Southern Observatory archive;
Goodman = Goodman High Throughput Spectrograph on SOAR.
Note (3): Quality flags as follows:
Q0 = obvious rotation signal;
Q1 = questionable signal;
Q2 = spurious detection;
Q3 = light curve dominated by noise.
--------------------------------------------------------------------------------
History:
From electronic version of the journal
References:
Newton et al. Paper I. 2019ApJ...880L..17N 2019ApJ...880L..17N
Rizzuto et al. Paper II. 2020AJ....160...33R 2020AJ....160...33R
Mann et al. Paper III. 2020AJ....160..179M 2020AJ....160..179M
Newton et al. Paper IV. 2021AJ....161...65N 2021AJ....161...65N Cat. J/AJ/161/65
Tofflemire et al. Paper V. 2021AJ....161..171T 2021AJ....161..171T Cat. J/AJ/161/171
Mann et al. Paper VI. 2022AJ....163..156M 2022AJ....163..156M This catalog
Newton et al. Paper VII. 2022AJ....164..115N 2022AJ....164..115N Cat. J/AJ/164/115
Barber et al. Paper VIII. 2022AJ....164...88B 2022AJ....164...88B Cat. J/AJ/164/88
Wood et al. Paper IX. 2023AJ....165...85W 2023AJ....165...85W Cat. J/AJ/165/85
Thao et al. Paper X. 2024AJ....168...41T 2024AJ....168...41T Cat. J/AJ/168/41
Capistrant et al. Paper XI. 2024AJ....167...54C 2024AJ....167...54C
(End) Prepared by [AAS], Coralie Fix [CDS], 25-Apr-2022