- ID:
- ivo://CDS.VizieR/J/ApJS/211/24
- Title:
- Rotation periods of Kepler MS stars
- Short Name:
- J/ApJS/211/24
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We analyzed three years of data from the Kepler space mission to derive rotation periods of main-sequence stars below 6500K. Our automated autocorrelation-based method detected rotation periods between 0.2 and 70 days for 34030 (25.6%) of the 133030 main-sequence Kepler targets (excluding known eclipsing binaries and Kepler Objects of Interest), making this the largest sample of stellar rotation periods to date. In this paper we consider the detailed features of the now well-populated period-temperature distribution and demonstrate that the period bimodality, first seen by McQuillan et al. (2013MNRAS.432.1203M) in the M-dwarf sample, persists to higher masses, becoming less visible above 0.6M_{sun}_. We show that these results are globally consistent with the existing ground-based rotation-period data and find that the upper envelope of the period distribution is broadly consistent with a gyrochronological age of 4.5Gyr, based on the isochrones of Barnes (2007ApJ...669.1167B), Mamajek, & Hillenbrand (Cat. J/ApJ/687/1264) and Meibom et al. (Cat. J/ApJ/695/679). We also performed a detailed comparison of our results to those of Reinhold et al. (Cat. J/A+A/560/A4) and Nielsen et al. (Cat. J/A+A/557/L10), who measured rotation periods of field stars observed by Kepler. We examined the amplitude of periodic variability for the stars with detection rotation periods, and found a typical range between ~950 ppm (5th percentile) and ~22700ppm (95th percentile), with a median of ~5600ppm. We found typically higher amplitudes for shorter periods and lower effective temperatures, with an excess of low-amplitude stars above ~5400K.
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Search Results
- ID:
- ivo://CDS.VizieR/J/A+A/557/L10
- Title:
- Rotation periods of 12000 Kepler stars
- Short Name:
- J/A+A/557/L10
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We aim to measure the starspot rotation periods of active stars in the Kepler field as a function of spectral type and to extend reliable rotation measurements from F-, G-, and K-type to M-type stars. Using the Lomb-Scargle periodogram we searched more than 150000 stellar light curves for periodic brightness variations.
- ID:
- ivo://CDS.VizieR/J/MNRAS/432/1203
- Title:
- Rotation periods of M-dwarf stars
- Short Name:
- J/MNRAS/432/1203
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We have analysed 10 months of public data from the Kepler space mission to measure rotation periods of main-sequence stars with masses between 0.3 and 0.55M_{sun}_. To derive the rotational period, we introduce the autocorrelation function and show that it is robust against phase and amplitude modulation and residual instrumental systematics. Of the 2483 stars examined, we detected rotation periods in 1570 (63.2%), representing an increase of a factor of ~30 in the number of rotation period determination for field M dwarfs. The periods range from 0.37 to 69.7d, with amplitudes ranging from 1.0 to 140.8mmag. The rotation period distribution is clearly bimodal, with peaks at ~19 and ~33d, hinting at two distinct waves of star formation, a hypothesis that is supported by the fact that slower rotators tend to have larger proper motions. The two peaks of the rotation period distribution form two distinct sequences in period-temperature space, with the period decreasing with increasing temperature, reminiscent of the Vaughan-Preston gap. The period-mass distribution of our sample shows no evidence of a transition at the fully convective boundary. On the other hand, the slope of the upper envelope of the period-mass relation changes sign around 0.55M_{sun}_, below which period rises with decreasing mass.
- ID:
- ivo://CDS.VizieR/J/MNRAS/407/1657
- Title:
- Rotation velocities of dwarf M stars
- Short Name:
- J/MNRAS/407/1657
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We have measured vsini for a selected sample of dM1-type stars. We give 114 measurements of vsini for 88 different stars, and six upper detection limits. These are the first measurements of vsini for most of the stars studied here. This represents the largest sample of vsini measurements for M dwarfs at a given spectral type. For these measurements, we used four different spectrographs: HARPS (ESO), SOPHIE (OHP), ELODIE (OHP) and UVES (ESO). Two of these spectrographs (HARPS and SOPHIE) are particularly stable in wavelength since they were designed for exoplanet searches.
- ID:
- ivo://CDS.VizieR/J/MNRAS/416/2233
- Title:
- Rotation velocity of dwarfs K5 stars
- Short Name:
- J/MNRAS/416/2233
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Using two different spectrographs, High Accuracy Radial velocity Planet Search (HARPS) (European Southern Observatory) and SOPHIE (Observatoire de Haute Provence), we have measured vsini for a sample of dK5 stars. These are the first measurements of vsini for most of the stars studied here. We measured vsini to an accuracy of 0.3km/s and a detection limit of about 0.5-1km/s. All our targets have similar (R-I)c colour. This is an advantage and facilitates the determination of the narrowest line profiles for vsini~0. In our total sample, we detected rotation for 22 stars (three dK5e and 19 dK5 stars), and we did not detect rotation in a further 22 stars. This result shows that there are many dK5 slow rotators, and many more than for dM1 stars. We also report on a newly discovered dK5e star, McC 522, which is also the fastest rotator in our sample.
- ID:
- ivo://CDS.VizieR/J/AJ/155/79
- Title:
- RV & light curves data for 4 G-type dwarf stars
- Short Name:
- J/AJ/155/79
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We report the discovery of four close-in transiting exoplanets (HATS-50b through HATS-53b), discovered using the HATSouth three-continent network of homogeneous and automated telescopes. These new exoplanets belong to the class of hot Jupiters and orbit G-type dwarf stars, with brightness in the range V=12.5-14.0 mag. While HATS-53 has many physical characteristics similar to the Sun, the other three stars appear to be metal-rich ([Fe/H]=0.2-0.3), larger, and more massive. Three of the new exoplanets, namely HATS-50b, HATS-51b, and HATS-53b, have low density (HATS-50b: 0.39+/-0.10 M_J_, 1.130+/-0.075 R_J_; HATS-51b: 0.768+/-0.045 M_J_, 1.41+/-0.19 R_J_; HATS-53b: 0.595+/-0.089 M_J_, 1.340+/-0.056 R_J_) and similar orbital periods (3.8297 days, 3.3489 days, 3.8538 days, respectively). Instead, HATS-52b is more dense (mass 2.24+/-0.15 M_J_ and radius 1.382+/-0.086 R_J_) and has a shorter orbital period (1.3667 days). It also receives an intensive radiation from its parent star and, consequently, presents a high equilibrium temperature (T_eq_=1834+/-73 K). HATS-50 shows a marginal additional transit feature consistent with an ultra-short-period hot super Neptune (upper mass limit 0.16 M_J_), which will be able to be confirmed with TESS photometry.
- ID:
- ivo://CDS.VizieR/J/MNRAS/356/1583
- Title:
- RV of Sigma Ori low-mass candidate members
- Short Name:
- J/MNRAS/356/1583
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present radial velocities for 38 low-mass candidate members of the {sigma} Orionis young group. We have measured their radial velocities by cross-correlation of high-resolution (R>>6000) AF2/Wide Field Fibre Optical Spectrograph (WYFFOS) spectra of the gravity-sensitive NaI doublet at 8183,8195{AA}, on the nights of 2003 January 3 and 4. The total sample contained 117 objects, of which 54 have sufficient signal-to-noise ratio to detect NaI at an equivalent width of 3{AA}; however, we only detect NaI in 38 of these. This implies that very low-mass members of this young group display weaker NaI absorption than similarly aged objects in the Upper Scorpius OB association. We develop a technique to assess membership using radial velocities with a range of uncertainties that does not bias the selection when large uncertainties are present. The resulting membership probabilities are used to assess the issue of exclusion in photometric selections, and we find that very few members are likely to be excluded by such techniques. We also assess the level of contamination in the expected pre-main-sequence region of colour-magnitude space brighter than I=17. We find that contamination by non-members in the expected pre-main-sequence region of the colour-magnitude diagram is small. We conclude that although radial velocity alone is insufficient to confirm membership, high signal-to-noise ratio observations of the NaI doublet provide the opportunity to use the strength of NaI absorption in concert with radial velocities to asses membership down to the lowest masses, where lithium absorption no longer distinguishes youth.
- ID:
- ivo://CDS.VizieR/J/ApJS/247/11
- Title:
- RV photon limits of well-characterized F-M stars
- Short Name:
- J/ApJS/247/11
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The determination of extrasolar planet masses with the radial velocity (RV) technique requires spectroscopic Doppler information from the planet's host star, which varies with stellar brightness and temperature. We analyze the Doppler information in spectra from dwarfs of spectral types F-M utilizing empirical information from HARPS and CARMENES data and model spectra. We revisit the question of whether optical or near-infrared instruments are more efficient for RV observations in low-mass stars, and we come to the conclusion that an optical setup (BVR bands) is more efficient than a near-infrared one (YJHK) in dwarf stars hotter than 3200K. We publish a catalog of 46480 well-studied F-M dwarfs in the solar neighborhood, and we compare its distribution to more than 1 million stars from Gaia DR2. For all stars, we estimate the RV photon noise achievable in typical observations under the assumption of no activity jitter and slow rotation. We find that with an ESPRESSO-like instrument at an 8m telescope, a photon noise limit of 10cm/s or lower can be reached in more than 280 stars in a 5 minute observation. At 4m telescopes, a photon noise limit of 1m/s can be reached in a 10 minute exposure in approximately 10000 predominantly Sun-like stars with a HARPS-like (optical) instrument. The same applies to ~3000 stars for a red optical setup that covers the R and I bands and ~700 stars for a near-infrared instrument. For the latter two, many of the targets are nearby M dwarfs. Finally, we identify targets in which Earth-mass planets within the liquid water habitable zone can cause RV amplitudes comparable to the RV photon noise. Assuming the same exposure times as above, we find that an ESPRESSO-like instrument can reach this limit for 1M_{Earth}_ planets in more than 1000 stars. The optical, red optical, and near-infrared configurations reach the limit for 2M_{Earth}_ planets in approximately 500, 700, and 200 stars, respectively. An online tool is provided to estimate the RV photon noise as a function of stellar temperature and brightness and wavelength coverage.
- ID:
- ivo://CDS.VizieR/J/AJ/157/55
- Title:
- RVs and light curves for HATS-60-HATS-69
- Short Name:
- J/AJ/157/55
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We report the discovery of 10 transiting extrasolar planets by the HATSouth survey. The planets range in mass from the super-Neptune HATS-62b, with M_p_<0.179 M_J_, to the super-Jupiter HATS-66b, with M_p_=5.33 M_J_, and in size from the Saturn HATS-69b, with R_p_=0.94 R_J_, to the inflated Jupiter HATS-67b, with R_p_=1.69 R_J_. The planets have orbital periods between 1.6092 days (HATS-67b) and 7.8180 days (HATS-61b). The hosts are dwarf stars with masses ranging from 0.89 M_{sun}_ (HATS-69) to 1.56 M_{sun}_ (HATS-64) and have apparent magnitudes between V=12.276+/-0.020 mag (HATS-68) and V=14.095+/-0.030 mag (HATS-66). The super-Neptune HATS-62b is the least massive planet discovered to date with a radius larger than Jupiter. Based largely on the Gaia DR2 distances and broadband photometry, we identify three systems (HATS-62, HATS-64, and HATS-65) as having possible unresolved binary star companions. We discuss in detail our methods for incorporating the Gaia DR2 observations into our modeling of the system parameters and into our blend analysis procedures.
- ID:
- ivo://CDS.VizieR/J/AJ/159/290
- Title:
- RVs of 12 spectroscopic binaries M-dwarfs
- Short Name:
- J/AJ/159/290
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present the spectroscopic orbits of 11 nearby, mid-to-late M dwarf binary systems in a variety of configurations: 2 single-lined binaries (SB1s), 7 double-lined binaries (SB2s), 1 double-lined triple (ST2), and 1 triple-lined triple (ST3). Eight of these orbits are the first published for these systems, while five are newly identified multiples. We obtained multi-epoch, high-resolution spectra with the TRES instrument on the 1.5m Tillinghast Reflector at the Fred Lawrence Whipple Observatory located on Mt. Hopkins in AZ. Using the TiO molecular bands at 7065-7165{AA}, we calculated radial velocities for these systems, from which we derived their orbits. We find LHS 1817 to have in a 7hr period a companion that is likely a white dwarf, due to the ellipsoidal modulation we see in our MEarth-North light-curve data. We find G123-45 and LTT11586 to host companions with minimum masses of 41MJup and 44MJup with orbital periods of 35 and 15days, respectively. We find 2MA0930+0227 to have a rapidly rotating stellar companion in a 917 day orbital period. GJ268, GJ1029, LP734-34, GJ1182, G258-17, and LTT7077are SB2s with stellar companions with orbital periods of 10, 96, 34, 154, 5, and 84days; LP655-43 is an ST3 with one companion in an 18day orbital period and an outer component in a longer undetermined period. In addition, we present radial velocities for both components of L870-44AB and for the outer components of LTT11586 and LP655-43.
