J/ApJ/944/L41 In-transit sp. and phot. obs. of TOI-2076b (Frazier+, 2023)
NEID reveals that the young warm Neptune TOI-2076 b has a low obliquity.
Frazier R.C., Stefansson G., Mahadevan S., Yee S.W., Canas C.I.,
Winn J.N., Luhn J., Dai F., Doyle L., Cegla H., Kanodia S., Robertson P.,
Wisniewski J., Bender C.F., Dong J., Gupta A.F., Halverson S., Hawley S.,
Hebb L., Holcomb R., Kowalski A., Libby-Roberts J., Lin A.S.J.,
McElwain M.W., Ninan J.P., Petrovich C., Roy A., Schwab C., Terrien R.C.,
Wright J.T.
<Astrophys. J., 944, L41 (2023)>
=2023ApJ...944L..41F 2023ApJ...944L..41F
ADC_Keywords: Exoplanets; Photometry; Spectra, optical; Radial velocities
Keywords: Exoplanet dynamics ; Exoplanet astronomy ; Radial velocity ;
Transit photometry ; Exoplanets ; Mini Neptunes ; Exoplanet evolution
Abstract:
TOI-2076 b is a sub-Neptune-sized planet (R=2.39±0.10R⊕)
that transits a young (204±50MYr) bright (V=9.2) K-dwarf hosting a
system of three transiting planets. Using spectroscopic observations
obtained with the NEID spectrograph on the WIYN 3.5m Telescope, we
model the Rossiter-McLaughlin effect of TOI-2076 b, and derive a
sky-projected obliquity of λ=-3-15+16°. Using the size
of the star (R=0.775±0.015R☉), and the stellar rotation period
(Prot=7.27±0.23days), we estimate an obliquity of
psi=18-9+10° (ψ<34° at 95% confidence), demonstrating
that TOI-2076 b is in a well-aligned orbit. Simultaneous
diffuser-assisted photometry from the 3.5m telescope at Apache Point
Observatory rules out flares during the transit. TOI-2076 b joins a
small but growing sample of young planets in compact multi-planet
systems with well-aligned orbits, and is the fourth planet with an age
≲300Myr in a multi-transiting system with an obliquity measurement.
The low obliquity of TOI-2076 b and the presence of transit timing
variations in the system suggest the TOI-2076 system likely formed via
convergent disk migration in an initially well-aligned disk.
Description:
We observed a transit of TOI-2076 b with the NEID spectrograph on the
WIYN 3.5m Telescope at Kitt Peak Observatory 33 on the night of
2022 February 13 for 5.5hr. NEID is a high-resolution (R∼113000)
spectrograph covering a broad wavelength range from 380 to 930nm. In
total, using an exposure time of 600s, we obtained 33 spectra spanning
a period of 1hr before and after the 3.3hr transit. The resulting
median signal-to-noise ratio (S/N) was 105.1 at 5500Å. The target
rose from airmass 1.90 to 1.02 during the observation.
See Section 2.2.
During the spectroscopic transit, we obtained simultaneous photometry
using the engineered diffuser available on the Astrophysical Research
Council Telescope Imaging Camera (ARCTIC) instrument on the ARC 3.5m
telescope at APO. We observed the transit using the Sloan Digital Sky
Survey (SDSS) i' filter with a short exposure time of 8s due to the
brightness of the host star. We used ARCTIC's 2x2 binning mode,
resulting in a gain of 2.0 e/ADU and a plate scale of 0.22"/pixel. The
target rose from airmass 1.72 to 1.01 during the observations.
See Section 2.3.
Objects:
----------------------------------------------------------
RA (ICRS) DE Designation(s)
----------------------------------------------------------
14 29 34.24 +39 47 25.5 TOI-2076b = BD+40 2790b
----------------------------------------------------------
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
arctic.dat 62 1544 *Data behind Figure 2a and 2b -- Diffuser assisted
transits taken with the 3.5m telescope at
Apache Point Observatory
rvfit.dat 55 19 *Data behind Figures 2c, 2d, 2e, and 2f -- RV data
taken with the NEID Spectrograph at WIYN Observatory
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Note on arctic.dat: Figure 2 is composed of sections:
a) Diffuser-assisted photometry from APO with the transit model from
the joint APO and TESS fit and the linear model of the airmass.
b) Diffuser-assisted photometry and the joint transit model detrended
from the linear model of the airmass.
Note on rvfit.dat: Figure 2 is composed of sections:
c) NEID RV data during the transit of TOI-2076 b
d) NEID RV data detrended from the overall upward slope and the
corresponding residuals.
e) Halpha index from NEID RV observations.
f) Chromatic index (CRX) from NEID RV observations.
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See also:
I/350 : Gaia EDR3 (Gaia Collaboration, 2020)
VI/120 : High-resolution synthetic stellar library (Coelho+, 2005)
J/ApJ/723/L223 : Radial velocities of HAT-P-11 (Winn+, 2010)
J/ApJ/757/18 : RVels for 16 hot Jupiter host stars (Albrecht+, 2012)
J/ApJ/834/17 : Mass & radius of planets, moons, low mass stars (Chen+, 2017)
J/ApJ/836/77 : A library of high-S/N optical sp. of FGKM stars (Yee+, 2017)
J/AJ/160/192 : Photometry and RVs of K2-25b with HPF (Stefansson+, 2020)
J/other/ExA/51.109 : Transit KELT-11b observed by CHEOPS (Benz+, 2021)
J/AJ/161/119 : The TESS-Keck survey. IV. Rvel for WASP-107 (Rubenzahl+, 2021)
J/A+A/664/A156 : Young sub-Neptunes orbiting TOI-2076 LCs (Osborn+, 2022)
J/AJ/165/33 : HIRES TOI-1136s planets radial velocities (Dai+, 2023)
Byte-by-byte Description of file: arctic.dat
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Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 14 F14.6 d BJD Barycentric Julian Date at TDB of measurement
16- 22 F7.5 --- Flux Normalized flux
24- 30 F7.5 --- e_Flux Error on Flux
32- 38 F7.5 --- LModel Model, AIRMASS linear parameter + out of
transit flux
40- 46 F7.5 --- Fmodel Full transit model with linear parameter
48- 54 F7.5 --- Flux0 Detrended normalized flux (1)
56- 62 F7.5 --- Fmodel0 Detrended full transit model (2)
--------------------------------------------------------------------------------
Note (1): (normalized flux + 1) - (model of the AIRMASS linear parameter +
out of transit flux); [flux] + 1 - [linear-model]
Note (2): full transit model [full-model] + 1 - out of transit flux
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Byte-by-byte Description of file: rvfit.dat
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Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 14 F14.6 d BJD Barycentric Julian Date at TDB of
measurement
16- 20 F5.2 m/s rv Radial velocity
22- 25 F4.2 m/s e_rv Radial velocity error
27- 31 F5.2 m/s rv0 Detrended radial velocity data (1)
33- 38 F6.4 --- Halpha H-alpha index (2)
40- 45 F6.4 --- e_Halpha Error on H-alpha
47- 51 F5.1 --- crx Chromatic Index, m/s/Neper (3)
53- 55 F3.1 --- e_crx Error on crx
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Note (1): radial velocity data with the upward slope subtracted.
Note (2): as calculated by SERVAL, Spectrum Radial Velocity Analyzer;
Zechmeister+ 2018A&A...609A..12Z 2018A&A...609A..12Z
Note (3): as calculated by SERVAL, Spectrum Radial Velocity Analyzer;
Zechmeister+ 2018A&A...609A..12Z 2018A&A...609A..12Z and measured in velocity per unit
wavelength ratio.
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History:
From electronic version of the journal
(End) Prepared by [AAS], Emmanuelle Perret [CDS] 28-Jan-2025