The CARMENES search for exoplanets around M dwarfs. Activity indicators at visible and near-infrared wavelengths

Abstract

The CARMENES survey is searching for Earth-like planets orbiting M dwarfs using the radial velocity method. Studying the stellar activity of the target stars is important to avoid false planet detections and to improve our understanding of the atmospheres of late-type stars. In this work we present measurements of activity indicators at visible and near-infrared wavelengths for 331 M dwarfs observed with CARMENES. Our aim is to identify the activity indicators that are most sensitive and easiest to measure, and the correlations among these indicators. We also wish to characterise their variability. Using a spectral subtraction technique, we measured pseudo-equivalent widths of the He I D3, H$\alpha$, He I $\lambda$10833 Å, and Pa$\beta$ lines, the Na I D doublet, and the Ca II infrared triplet, which have a chromospheric component in active M dwarfs. In addition, we measured an index of the strength of two TiO and two VO bands, which are formed in the photosphere. We also searched for periodicities in these activity indicators for all sample stars using generalised Lomb-Scargle periodograms. We find that the most slowly rotating stars of each spectral subtype have the strongest H$\alpha$ absorption. H$\alpha$ is correlated most strongly with He I D3, whereas Na I D and the Ca II infrared triplet are also correlated with H$\alpha$. He I $\lambda$10833 Å and Pa$\beta$ show no clear correlations with the other indicators. The TiO bands show an activity effect that does not appear in the VO bands. We find that the relative variations of H$\alpha$ and He I D3 are smaller for stars with higher activity levels, while this anti-correlation is weaker for Na I D and the Ca II infrared triplet, and is absent for He I $\lambda$10833 Å and Pa$\beta$. Periodic variation with the rotation period most commonly appears in the TiO bands, H$\alpha$, and in the Ca II infrared triplet.

arXiv comment16 pages + 2 pages appendix, 11 figures, 3+1 tables, accepted for publication by A&A

References in corpus (63)

• Intrinsic Colors, Temperatures, and Bolometric Corrections of Pre-Main Sequence Stars
• The generalised Lomb-Scargle periodogram. A new formalism for the floating-mean and Keplerian periodograms
• No planet for HD 166435
• Constraining the Age-Activity Relation for Cool Stars: The SDSS DR5 Low-Mass Star Spectroscopic Sample
• Contributions to the Nearby Stars (NStars) Project: Spectroscopy of Stars Earlier than M0 within 40 parsecs: The Southern Sample
• Contributions to the Nearby Stars (NStars) Project: Spectroscopy of Stars Earlier than M0 within 40 parsecs: The Northern Sample I
• Spectrum radial velocity analyser (SERVAL). High-precision radial velocities and two alternative spectral indicators
• Late-type stars members of young stellar kinematic groups - I. Single stars
• Rotation and Activity in Mid-M to L Dwarfs
• Stellar SEDs from 0.3-2.5 Microns: Tracing the Stellar Locus and Searching for Color Outliers in SDSS and 2MASS
• Characterization of M,L and T dwarfs in the Sloan Digital Sky Survey
• Helium in the eroding atmosphere of an exoplanet
• The H$\alpha$ emission of nearby M dwarfs and its relation to stellar rotation
• The Palomar/MSU Nearby Star Spectroscopic Survey III: Chromospheric Activity, M-dwarf Ages and the Local Star Formation History
• Spectroscopic Properties of Cool Stars in the SDSS: An Analysis of Magnetic Activity and a Search for Subdwarfs
• The Sloan Digital Sky Survey Data Release 7 Spectroscopic M Dwarf Catalog I: Data
• A simple method to estimate radial velocity variations due to stellar activity using photometry
• Trumpeting M Dwarfs with CONCH-SHELL: a Catalog of Nearby Cool Host-Stars for Habitable ExopLanets and Life
• The rotation and Galactic kinematics of mid M dwarfs in the Solar Neighborhood
• Ground-based detection of an extended helium atmosphere in the Saturn-mass exoplanet WASP-69b
• A Spectroscopic Catalog of the Brightest (J<9) M Dwarfs in the Northern Sky
• Chromospheric Activity, Rotation, and Rotational Braking in M and L Dwarfs
• The CARMENES search for exoplanets around M dwarfs: High-resolution optical and near-infrared spectroscopy of 324 survey stars
• Near-infrared Metallicities, Radial Velocities and Spectral Types for 447 Nearby M Dwarfs
• Revised metallicity classes for low-mass stars: dwarfs (dM), subdwarfs (sdM), extreme subdwarfs (esdM), and ultra subdwarfs (usdM)
• Magnetic Cycles and Rotation Periods of Late Type Stars from photometric time series
• Rotation periods of late-type dwarf stars from time-series high-resolution spectroscopy of chromospheric indicators
• A catalogue of rotation and activity in early-M stars
• A Volume-limited Sample of 63 M7-M9.5 Dwarfs II. Activity, magnetism, and the fade of the rotation-dominated dynamo
• Activity and Kinematics of Ultracool Dwarfs Including An Amazing Flare Observation
• Identifying the Young Low-mass Stars within 25 pc. I. Spectroscopic Observations
• CARMENES input catalogue of M dwarfs. I. Low-resolution spectroscopy with CAFOS
• A Neptune-sized transiting planet closely orbiting a 5-10-million-year-old star
• Rotation Velocities for M-dwarfs
• Spectroscopy of New High Proper Motion Stars in the Northern Sky. I. New Nearby Stars, New High Velocity Stars, and an Enhanced Classification Scheme for M Dwarfs
• An Activity-Rotation Relationship and Kinematic Analysis of Nearby Mid-to-Late-type M Dwarfs
• Detection of He I $\lambda 10830$ Å absorption on HD 189733 b with CARMENES high-resolution transmission spectroscopy
• Flat-relative optimal extraction. A quick and efficient algorithm for stabilised spectrographs
• CARMENES input catalogue of M dwarfs: III. Rotation and activity from high-resolution spectroscopic observations
• Strong dipole magnetic fields in fast rotating fully convective stars
• Long-term magnetic activity of a sample of M-dwarf stars from the HARPS program II. Activity and radial velocity
• H-alpha Activity of Old M Dwarfs: Stellar Cycles and Mean Activity Levels For 93 Low-Mass Stars in the Solar Neighborhood
• The Solar Neighborhood. XXXIII. Parallax Results from the CTIOPI 0.9m Program: Trigonometric Parallaxes of Nearby Low-Mass Active and Young Systems
• Spitzer Observations Confirm and Rescue the Habitable-Zone Super-Earth K2-18b for Future Characterization
• Remarks on statistical errors in equivalent widths
• CARMENES input catalogue of M dwarfs IV. New rotation periods from photometric time series
• CARMENES input catalogue of M dwarfs II. High-resolution imaging with FastCam
• The CARMENES search for exoplanets around M dwarfs - Photospheric parameters of target stars from high-resolution spectroscopy
• The χFactor: Determining the Strength of Activity in Low Mass Dwarfs
• Precision radial velocities of 15 M5 - M9 dwarfs
• Search for nearby stars among proper motion stars selected by optical-to-infrared photometry III. Spectroscopic distances of 322 NLTT stars
• Thirty New Low-Mass Spectroscopic Binaries
• MOST Observations of the Flare Star AD Leo
• The Ca II infrared triplet's performance as an activity indicator compared to Ca II H and K
• A 3D Search for Companions to 12 Nearby M-Dwarfs
• Active cool stars and He I 10830 Å: the coronal connection
• The CARMENES search for exoplanets around M dwarfs: Nine new double-line spectroscopic binary stars
• Probing the Flare Atmospheres of M dwarfs Using Infrared Emission Lines
• Proxima Centauri as a Benchmark for Stellar Activity Indicators in the Near Infrared
• Hα Emission Variability in Active M Dwarfs
• The Sloan digital sky survey data release 7 spectroscopic m dwarf catalog iii: The spatial dependence of magnetic activity in the galaxy
• Dynamics of rotation in M dwarfs: Indications for a change in the dynamo regime in stars at the onset of complete convection
• K2-155: A Bright Metal-Poor M Dwarf with Three Transiting Super-Earths

Cited by in corpus (77)

• The CARMENES search for exoplanets around M dwarfs: Different roads to radii and masses of the target stars
• Magnetism, rotation, and nonthermal emission in cool stars -- Average magnetic field measurements in 292 M dwarfs
• SPIRou: nIR velocimetry & spectropolarimetry at the CFHT
• CARMENES input catalogue of M dwarfs V. Luminosities, colours, and spectral energy distributions
• The CARMENES search for exoplanets around M dwarfs -- Planet occurrence rates from a subsample of 71 stars
• Planetary system around the nearby M dwarf GJ 357 including a transiting, hot, Earth-sized planet optimal for atmospheric characterization
• The CARMENES search for exoplanets around M dwarfs. Stellar atmospheric parameters of target stars with SteParSyn
• The CARMENES search for exoplanets around M dwarfs. Guaranteed time observations Data Release 1 (2016-2020)
• The CARMENES search for exoplanets around M dwarfs -- Photospheric parameters of target stars from high-resolution spectroscopy. II. Simultaneous multiwavelength range modeling of activity insensitive lines
• Investigating the young AU~Mic system with SPIRou: large-scale stellar magnetic field and close-in planet mass
• A nearby transiting rocky exoplanet that is suitable for atmospheric investigation
• The CARMENES search for exoplanets around M dwarfs. Measuring precise radial velocities in the near infrared: the example of the super-Earth CD Cet b
• The CARMENES search for exoplanets around M dwarfs. Three temperate to warm super-Earths
• A detailed analysis of the Gl 486 planetary system
• The CARMENES search for exoplanets around M dwarfs -- LP 714-47b (TOI 442.01): Populating the Neptune desert
• Precise mass and radius of a transiting super-Earth planet orbiting the M dwarf TOI-1235: a planet in the radius gap?
• An ultra-short-period transiting super-Earth orbiting the M3 dwarf TOI-1685
• The CARMENES search for exoplanets around M dwarfs. Mapping stellar activity indicators across the M dwarf domain
• Discovery of a hot, transiting, Earth-sized planet and a second temperate, non-transiting planet around the M4 dwarf GJ 3473 (TOI-488)
• Mass and density of the transiting hot and rocky super-Earth LHS 1478 b (TOI-1640 b)
• Near-infrared Accretion Signatures from the Circumbinary Planetary Mass Companion Delorme 1 (AB)b
• The CARMENES search for exoplanets around M dwarfs: Stable radial-velocity variations at the rotation period of AD~Leonis -- A test case study of current limitations to treating stellar activity
• The CARMENES search for exoplanets around M dwarfs: Benchmarking the impact of activity in high-precision radial velocity measurements
• The HD 260655 system: Two rocky worlds transiting a bright M dwarf at 10 pc
• Estimating the atmospheric properties of 44 M dwarfs from SPIRou spectra
• Gliese 49: Activity evolution and detection of a super-Earth
• The CARMENES search for exoplanets around M dwarfs, Wolf 1069 b: Earth-mass planet in the habitable zone of a nearby, very low-mass star
• The CARMENES search for exoplanets around M dwarfs: Two Saturn-mass planets orbiting active stars
• TOI-1468: A system of two transiting planets, a super-Earth and a mini-Neptune, on opposite sides of the radius valley
• The CARMENES search for exoplanets around M dwarfs. A long-period planet around GJ 1151 measured with CARMENES and HARPS-N data
• Early science with SPIRou: near-infrared radial velocity and spectropolarimetry of the planet-hosting star HD 189733
• GJ357: A low-mass planetary system uncovered by precision radial-velocities and dynamical simulations
• A transiting, temperate mini-Neptune orbiting the M dwarf TOI-1759 unveiled by TESS
• The CARMENES search for exoplanets around M dwarfs. Two terrestrial planets orbiting G 264-012 and one terrestrial planet orbiting Gl 393
• The CARMENES search for exoplanets around M dwarfs: Rubidium abundances in nearby cool stars
• Discovery and mass measurement of the hot, transiting, Earth-sized planet GJ 3929 b
• The CARMENES search for exoplanets around M dwarfs: Spectroscopic orbits of nine M-dwarf multiple systems, including two triples, two brown dwarf candidates, and one close M-dwarf-white dwarf binary
• Optical and near-infrared stellar activity characterization of the early M dwarf Gl~205 with SOPHIE and SPIRou
• The CARMENES search for exoplanets around M dwarfs. Variability on long timescales as seen in chromospheric indicators
• The CARMENES search for exoplanets around M dwarfs. Rotational variation in activity indicators of Ross 318, YZ CMi, TYC 3529-1437-1, and EV Lac
• The CARMENES search for exoplanets around M dwarfs. A super-Earth planet orbiting HD 79211 (GJ 338 B)
• GJ 806 (TOI-4481): A bright nearby multi-planetary system with a transiting hot, low-density super-Earth
• Variability Timescales of H$\alpha$ on Active Mid-to-Late M dwarfs
• The CARMENES search for exoplanets around M dwarfs. Diagnostic capabilities of strong K I lines for photosphere and chromosphere
• Complete X-ray census of Mdwarfs in the solar Neighborhood I. GJ 745 AB: Coronal-hole Stars in the 10 pc Sample
• Mon-735: A new low-mass pre-main sequence eclipsing binary in NGC 2264
• High resolution near-infrared spectroscopy of a flare around the ultracool dwarf vB 10
• Using autoencoders and deep transfer learning to determine the stellar parameters of 286 CARMENES M dwarfs
• A multi-planetary system orbiting the early-M dwarf TOI-1238
• TOI-4438 b: a transiting mini-Neptune amenable to atmospheric characterization
• Confirmation of the Long-Period Planet Orbiting Gliese 411 and the Detection of a New Planet Candidate
• Planetary companions orbiting the M dwarfs GJ 724 and GJ 3988. A CARMENES and IRD collaboration
• GJ 357 b: A Super-Earth Orbiting an Extremely Inactive Host Star
• The CARMENES search for exoplanets around M dwarfs. Revisiting the GJ 581 multi-planetary system with new Doppler measurements from CARMENES, HARPS, and HIRES
• The CARMENES search for exoplanets around M dwarfs. Behaviour of the Paschen lines during flares and quiescence
• The CARMENES search for exoplanets around M dwarfs. Line-by-line sensitivity to activity in M dwarfs
• The corona -- chromosphere connection studied with simultaneous eROSITA and TIGRE observations
• Exploring the short-term variability of H$\alpha$ and H$\beta$ emissions in a sample of M dwarfs
• Two sub-Neptunes around the M dwarf TOI-1470
• The CARMENES search for exoplanets around M dwarfs. Occurrence rates of Earth-like planets around very low-mass stars
• IGRINS RV: A Precision RV Pipeline for IGRINS Using Modified Forward Modeling in the Near-Infrared
• The CARMENES search for exoplanets around M dwarfs. A sub-Neptunian mass planet in the habitable zone of HN Lib
• Detection of H${}_2$ in the TWA 7 System: A Probable Circumstellar Origin
• Non-thermal motions and atmospheric heating of cool stars
• Precise radial velocities of giant stars -- XVII. Distinguishing planets from intrinsically induced radial velocity signals in evolved stars
• Enhancing the detection of low-energy M dwarf flares: Wavelet-based denoising of CHEOPS data
• Characterizing planetary systems with SPIRou: Detection of a sub-Neptune in a 6-day period orbit around the M dwarf Gl 410
• The CARMENES search for exoplanets around M dwarfs : Understanding the wavelength dependence of radial velocity measurements
• iSTARMOD: A Python Code to Quantify Chromospheric Activity by Using the Spectral Subtraction Technique
• Constraining an exoplanets magnetic field using star-planet interactions
• Simultaneous photometric and CARMENES spectroscopic monitoring of fast-rotating M dwarf GJ 3270. Discovery of a post-flare corotating feature
• The CARMENES search for exoplanets around M dwarfs, No evidence for a super-Earth in a 2-day orbit around GJ 1151
• Metallicities in M dwarfs: Investigating different determination techniques
• The CARMENES search for exoplanets around M dwarfs. A homogeneous catalogue of projected rotational velocities accounting for limb-darkening
• CARMENES input catalog of M dwarfs VI. A time-resolved Ca II H&K catalog from archival data
• Spectroscopic Characterization of LOFAR Radio-emitting M dwarfs
• TOI-1201 b: A mini-Neptune transiting a bright and moderately young M dwarf