J/AJ/170/122 APO ACCELS. Ages, Li EW, & Prot for 166 accel. stars (Peck+, 2025)
Apache Point Observatory follow-up of ACcelerating Candidate ExopLanet Host
Stars (APO ACCELS): Ages for 166 accelerating stars in the northern hemisphere.
Peck A.E., Nielsen E.L., De Rosa R.J., Thompson W., Macintosh B.,
Roberson W., Smith A.J.R.W., Klusmeyer J., Abbas A., Jackiewicz J.,
Holtzman J., Gallamore H., Brinjikji M., Patience J., Nguyen J.S.,
Madurowicz A., Savransky D.
<Astron. J., 170, 122 (2025)>
=2025AJ....170..122P 2025AJ....170..122P
ADC_Keywords: Exoplanets; Stars, double and multiple; Equivalent widths;
Stars, ages; Stars, activity; Photometry; Optical
Keywords: Planet hosting stars ; Exoplanet astronomy ; Stellar ages ;
Brown dwarfs ; Direct imaging ; Exoplanet detection methods
Abstract:
Directly imaged substellar companions with well-constrained ages and
masses serve as vital empirical benchmarks for planet formation and
evolution models. Potential benchmark companions can be identified
from astrometric accelerations of their host stars. We use Gaia DR3
and Hipparcos astrometry to identify 166 northern hemisphere stars
with astrometric accelerations consistent with a substellar companion
between 0.5" and 1". For this accelerating sample we identify young
stars using Apache Point Observatory/ARCES spectra and TESS light
curves. From spectroscopic screening of the sample, we measure ages
for 24 stars with detectable amounts of lithium, place lower age
limits on 135 stars with lithium nondetections, and measure ages from
R'HK for 34 stars. A total of 129 stars have TESS light curves, from
which we measure ages for 20 stars with rotation rates <15days, and we
identify three eclipsing binaries. We present median ages and
confidence intervals of age posteriors for the entire sample and
discuss how the overall age distribution of our sample compares to a
uniform star formation rate in the solar neighborhood. We identify 47
stars with median ages <2Gyr, 31 stars with median ages <1Gyr, and 14
stars with median ages <0.5Gyr, making them high-priority targets for
direct imaging follow-up.
Description:
We identify candidate exoplanet hosts by examining the Hipparcos-Gaia
Catalog of Accelerations presented in Brandt+2021 (J/ApJS/254/42)
created using the Gaia DR3 (I/255) catalog. We select stars with a
>4σ proper motion anomaly. We exclude known close binaries reported
in the Washington Double Star Catalog (WDS; Mason+2001, B/wds) or the 9th
Catalog of Spectroscopic Binary Orbits (SB9; Pourbaix+2004, B/sb9, V/122)
and stars with obvious companions in archival imaging data.
We limit our sample to stars observable from Apache Point Observatory
(APO). We obtain spectra using the Astronomy Research Consortium
Echelle Spectrograph (ARCES) on the APO 3.5m telescope. ARCES is a
multiuse spectrograph with an average spectral resolution (R=35,000)
covering 3200-10000Å. We achieve signal-to-noise ratios (SNRs)
between ∼20 for our faintest targets and ∼200 for our brightest stars.
The observing campaign began in 2020 October and is ongoing. We aim to
observe each star at least three times over several months to years.
As of writing, we have observed each star at least once and 98 out of
the 166 stars at least three times.
We measure rotation periods from TESS light curves, all with cadences
between 20 and 1800s, downloaded from the Mikulski Archive for Space
Telescopes (MAST). We found light curves for 129 of our sample stars and
identify periodic signals in the light curves of 34 of these 129 stars.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table3.dat 151 166 Complete sample of accelerating stars with age
posteriors and age tracers used
table4.dat 113 166 Lithium equivalent width measurements
table5.dat 75 166 Measured activity indices
table6.dat 86 166 Rotation period measurements
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See also:
B/wds : The Washington Visual Double Star Catalog (Mason+ 2001-)
B/sb9 : SB9: 9th Catalogue of Spectroscopic Binary Orbits (Pourbaix+ 2004-2014)
III/159A : Ca II H and K Measurements Made at MWO (Duncan+ 1991)
I/311 : Hipparcos, the New Reduction (van Leeuwen, 2007)
I/355 : Gaia DR3 Part 1. Main source (Gaia Collaboration, 2022)
V/122 : SB9: 9th Catalogue of Spectroscopic Binary Orbits (Pourbaix+ 2005)
J/AJ/105/2299 : Li abundance of solar-type stars. II. (Soderblom+, 1993)
J/AJ/126/2048 : NStars project: the Northern Sample. I. (Gray+, 2003)
J/ApJS/152/261 : Chromospheric Ca II emission in nearby stars (Wright+, 2004)
J/PASJ/57/45 : Lithium abundances of F-K stars (Takeda+, 2005)
J/AJ/133/2524 : Spectra of young nearby stars (White+, 2007)
J/A+A/484/815 : Scaled solar tracks and isochrones (Bertelli+, 2008)
J/ApJ/687/1264 : Age estimation for solar-type dwarfs (Mamajek+, 2008)
J/A+A/508/355 : Scaled solar tracks and isochrones (Bertelli+, 2009)
J/A+A/504/829 : Spectroscopic survey of youngest field stars (Guillout+, 2009)
J/A+A/530/A138 : Geneva-Copenhagen survey re-analysis (Casagrande+, 2011)
J/MNRAS/432/1203 : Rotation periods of M-dwarf stars (McQuillan+, 2013)
J/A+A/551/L8 : Chromospheric activity of field stars (Pace, 2013)
J/ApJS/208/9 : Intrinsic colors and temperatures of PMS stars (Pecaut+, 2013)
J/MNRAS/454/593 : Young moving groups in solar neighbourhood (Bell+, 2015)
J/other/Sci/350.64 : 51 Eri b near-infrared spectrum (Macintosh+, 2015)
J/MNRAS/458/2307 : gamma Dor stars spect. survey (Kahraman Alicavus+, 2016)
J/ApJ/856/23 : BANYAN. XI. The BANYAN Σ algorithm (Gagne+, 2018)
J/AJ/158/13 : The first 300 stars observed by the GPIES (Nielsen+, 2019)
J/ApJS/244/21 : Surface rotation & activity of Kepler stars. I. (Santos+, 2019)
J/ApJ/903/99 : Stellar spins in the open cluster NGC 2516 (Healy+, 2020)
J/ApJ/898/27 : Bayesian Ages For Field LowEr-mass Stars (Stanford-Moore+, 2020)
J/ApJS/254/42 : Hipparcos-Gaia (EDR3) Catalog of Accelerations (Brandt, 2021)
J/AJ/162/147 : Rot. periods of 43 TOIs with Evryscope and TESS (Howard+, 2021)
J/A+A/654/A137 : Evolution of Li in FGK dwarf stars (Llorente de Andres+, 2021)
J/ApJS/255/17 : Surface rot. & activity for Kepler stars. II. (Santos+, 2021)
J/ApJS/258/16 : TESS Eclipsing Binary stars. I. Sectors 1-26 (Prsa+, 2022)
J/AJ/165/39 : CHARIS and SPHERE/IFS IR spectra of HIP 21152 (Franson+, 2023)
J/A+A/672/A119 : 10 double-lined spectroscopic binaries data (Gallenne+, 2023)
J/A+A/672/A93 : AF Lep b spectrum (Mesa+, 2023)
Byte-by-byte Description of file: table3.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 3 A3 --- [HIP] [HIP] Link to the Hipparcos-Gaia Catalog of
Accelerations (Brandt+2021, J/ApJS/254/42)
5- 10 I6 --- HIP [143/118310] Hipparcos (I/311) identifier of
target
12- 13 I2 h RAh Hour of Right Ascension (J2000)
15- 16 I2 min RAm Minute of Right Ascension (J2000)
18- 22 F5.2 s RAs Second of Right Ascension (J2000)
24 A1 --- DE- Sign of the Declination (J2000)
25- 26 I2 deg DEd Degree of Declination (J2000)
28- 29 I2 arcmin DEm Arcminute of Declination (J2000)
31- 35 F5.2 arcsec DEs Arcsecond of Declination (J2000)
37- 43 F7.4 mag Gmag [2/12.1] Gaia DR3 G-band magnitude
45- 50 F6.4 mag e_Gmag [1e-4/0.01] Uncertainty in Gmag
52- 56 F5.3 mag B-V [0.04/1.63] Adopted B-V color excess
58- 62 F5.3 mag e_B-V [0.001/0.2] Uncertainty in B-V
64- 73 A10 --- SpType Simbad spectral type
75- 79 F5.2 pc Dist [14.37/49.78] Distance from Simbad (4)
81- 84 F4.2 pc e_Dist [0.01/1.33] Uncertainty in Dist
86- 100 A15 --- Tracers Age tracers (1)
102- 103 A2 --- l_Age [≤>] Limit flag on Age
105- 111 F7.2 Myr Age [119/9477]? Median Age
113- 114 A2 --- l_AgeInt1 [≤>] Limit flag for AgeInt1 (2)
116- 122 F7.2 Myr AgeInt1 [58.6/6862.5] Age Interval -- 68% confidence
interval or 95% lower limit (2)
124- 131 F8.2 Myr AgeInt2 [206/11766]? Age Interval -- 68% confidence
interval (2)
133- 134 A2 --- l_AgeInt3 [≤>] Limit flag for AgeInt3 (3)
136- 142 F7.2 Myr AgeInt3 [17.4/4396.2] Age Interval -- 95% confidence
interval or 99.7% lower limit (3)
144- 151 F8.2 Myr AgeInt4 [300/12807.2]? Age Interval -- 95% confidence
interval (3)
--------------------------------------------------------------------------------
Note (1): Age tracers as follows:
Li = Lithium (24 occurrences)
Li UL = Lithium Upper Limits (135 occurrences)
RpHK = R'HK, Calcium emission (34 occurrences)
Gyro = Rotation periods (20 occurrences)
CMD = Color-Magnitude Diagram positions (31 occurrences)
Note (2): AgeInt1 is either the 95% lower limit or the lower bound of the 68%
confidence interval.
Note (3): AgeInt3 is either the 99.7% lower limit or the lower bound of the 95%
confidence interval.
Note (4): The distances given on Simbad are calculated from the
Gaia EDR3 (I/350) measurements.
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Byte-by-byte Description of file: table4.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 3 A3 --- [HIP] [HIP] Link to the Hipparcos-Gaia Catalog of
Accelerations (Brandt+2021, J/ApJS/254/42)
5- 10 I6 --- HIP [143/118310] Hipparcos (I/311) identifier of
target
12- 16 F5.3 mag B-V [0.04/1.63] Adopted B-V color excess
18- 22 F5.3 mag e_B-V [0.001/0.2] Uncertainty in B-V
24- 25 A2 --- l_EWLi [≤>] Limit flag on EWLi
27- 32 F6.2 10-13m EWLi [1.63/125.14] Equivalent width, Li
34- 38 F5.2 10-13m e_EWLi [1.22/10.51]? Uncertainty in EWLi
40- 46 F7.2 Myr Age [173.8/9441]? BAFFLES median Age
48- 54 F7.2 Myr AgeInt1 [96.8/5780]? Age Interval -- 68% confidence
interval
56- 63 F8.2 Myr AgeInt2 [252.4/11966]? Age Interval -- 68% confidence
interval
65- 71 F7.2 Myr AgeInt3 [31.2/2460]? Age Interval -- 95% confidence
interval
73- 80 F8.2 Myr AgeInt4 [327/12856]? Age Interval -- 95% confidence
interval
82- 83 A2 --- l_AgeLim1 [≤>] Limit flag on AgeLim1
85- 91 F7.2 Myr AgeLim1 [62.8/1551.1]? Age lower limit
93- 94 A2 --- l_AgeLim2 [≤>] Limit flag on AgeLim2
96- 102 F7.2 Myr AgeLim2 [619/4260]? 95% Age lower limit
104- 105 A2 --- l_AgeLim3 [≤>] Limit flag on AgeLim3
107- 113 F7.2 Myr AgeLim3 [4144/8277]? 68% Age lower limit
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Byte-by-byte Description of file: table5.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 3 A3 --- [HIP] [HIP] Link to the Hipparcos-Gaia Catalog of
Accelerations (Brandt+2021, J/ApJS/254/42)
5- 10 I6 --- HIP [143/118310] Hipparcos (I/311) identifier of
target
12- 16 F5.3 mag B-V [0.04/1.7] Adopted B-V color excess
18- 22 F5.3 mag e_B-V [0.001/0.2] Uncertainty in B-V
24- 27 F4.2 --- SHK [0.05/4.53] Mt. Wilson SHK index
29- 33 F5.2 [-] logRHK [-5.23/-3.11] Log R'HK, the color- and
photospheric-corrected SHK value
35- 41 F7.2 Myr Age [3335/8918]? BAFFLES median Age from
log(R'HK)
43- 49 F7.2 Myr AgeInt1 [1782/5674]? Age Interval -- 68% confidence
interval
51- 58 F8.2 Myr AgeInt2 [6529/11624]? Age Interval -- 68% confidence
interval
60- 66 F7.2 Myr AgeInt3 [789/2818]? Age Interval -- 95% confidence
interval
68- 75 F8.2 Myr AgeInt4 [11322/12795]? Age Interval -- 95% confidence
interval
--------------------------------------------------------------------------------
Byte-by-byte Description of file: table6.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 3 A3 --- [HIP] [HIP] Link to the Hipparcos-Gaia Catalog of
Accelerations (Brandt+2021, J/ApJS/254/42)
5- 10 I6 --- HIP [143/118310] Hipparcos (I/311) identifier of
target
12- 15 I4 K Teff [3363/8718] Surface effective temperature from
gyro-interp
17- 19 I3 K e_Teff [45/670] Uncertainty in Teff
21- 25 F5.2 d Prot [2.53/10.33]? Measured rotational period
27- 30 F4.2 d e_Prot [0.11/2.02]? Uncertainty in Prot
32- 49 A18 --- f_Prot Flag on Prot (1)
51- 56 F6.2 Myr Age [95.6/913.9]? Median Age from gyro-interp
58- 63 F6.2 Myr AgeInt1 [30.09/563.46]? Age Interval -- 68% confidence
interval
65- 71 F7.2 Myr AgeInt2 [263.8/1914.7]? Age Interval -- 68% confidence
interval
73- 78 F6.2 Myr AgeInt3 [5.16/276.7]? Age Interval -- 95% confidence
interval
80- 86 F7.2 Myr AgeInt4 [419.9/2693.7]? Age Interval -- 95% confidence
interval
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Note (1): Flags on missing Prot as follows:
2 periods = multiple periods (2 occurrences)
contaminated pixel = contaminated pixel(s) (3 occurrences)
EB = eclipsing binary (3 occurrences)
no LC = light curve not available (37 occurrences)
no signal = no signal in light curve (92 occurrences)
not rotation = variability not due to rotation (7 occurrences)
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History:
From electronic version of the journal
License: CC-BY-4.0
(End) Prepared by [AAS], Robin Leichtnam [CDS] 16-Jun-2026