J/MNRAS/493/4570 Coronal mass ejections on solar-like stars (Leitzinger+, 2020)
A census of coronal mass ejections on solar-like stars.
Leitzinger M., Odert P., Greimel R., Vida K., Kriskovics L., Guenther E.W.,
Korhonen H., Koller F., Hanslmeier A., Kovari Z., Lammer H.
<Mon. Not. R. Astron. Soc., 493, 4570-4589 (2020)>
=2020MNRAS.493.4570L 2020MNRAS.493.4570L (SIMBAD/NED BibCode)
ADC_Keywords: Stars, flare ; Stars, activity ; Spectral types ;
Stars, distances ; Spectra, optical ; Ultraviolet ; X-ray sources
Keywords: stars: activity - stars: chromospheres - stars: flare -
stars: solar-type
Abstract:
Coronal mass ejections (CMEs) may have major importance for planetary
and stellar evolution. Stellar CME parameters, such as mass and
velocity, have yet not been determined statistically. So far only a
handful of stellar CMEs has been detected mainly on dMe stars using
spectroscopic observations. We therefore aim for a statistical
determination of CMEs of solar-like stars by using spectroscopic data
from the ESO phase 3 and Polarbase archives. To identify stellar CMEs,
we use the Doppler signal in optical spectral lines being a signature
of erupting filaments that are closely correlated to CMEs. We
investigate more than 3700h of on-source time of in total 425 dF-dK
stars. We find no signatures of CMEs and only few flares. To explain
this low level of activity, we derive upper limits for the
non-detections of CMEs and compare those with empirically modelled CME
rates. To explain the low number of detected flares, we adapt a flare
power law derived from EUV data to the Hα regime, yielding more
realistic results for Hα observations. In addition, we examine
the detectability of flares from the stars by extracting Sun-as-a-star
Hα light curves. The extrapolated maximum numbers of observable
CMEs are below the observationally determined upper limits, which
indicates that the on-source times were mostly too short to detect
stellar CMEs in Hα. We conclude that these non-detections are
related to observational biases in conjunction with a low level of
activity of the investigated dF-dK stars.
Description:
We select the Phase 3 archive of the European Southern Observatory
(ESO) (http://archive.eso.org/wdb/wdb/adp/phase3_main/form) and the
Polarbase archive (Petit et al. 2014PASP..126..469P 2014PASP..126..469P, Cat.
J/PASP/126/469) (http://polarbase.irap.omp.eu/) to search for optical
signatures of CMEs on F-K MS stars. It turned out that the High
Accuracy Radial velocity Planet Searcher (HARPS) mounted on the 3.6m
telescope in LaSilla yielded the largest number of target stars,
compared to other ESO instruments in the phase 3 archive. The
Polarbase archive includes spectral observations from the Echelle
Spectro Polarimetric Device for the Observation of Stars (ESPaDOnS)
instrument installed on the 3.6m Canada-France-Hawaii Telescope (CFHT)
and the Narval instrument installed on the 2.0m Telescope Bernard
Lyot.
In this study, we focus on solar-like stars (spectral types F-K). As a
base for target star selection, we use the catalogue of Hinkel et al.
(2017ApJ...848...34H 2017ApJ...848...34H, Cat. J/ApJ/848/34) who compiled a catalogue of
951 F-K stars within 30pc. Although the catalogue is not complete, as
it is based on the Tycho-Gaia Astrometric Solution that has an 80 per
cent completeness with respect to Hipparcos and Tycho-2, it represents
a solid base of target stars of spectral type F-K in the solar
neighbourhood. Because the catalogue is not complete, we add the
target sample from the 'Sun in time' project (see e.g. Gudel
2007LRSP....4....3G 2007LRSP....4....3G) as well as the target sample of Gaidos
(1998PASP..110.1259G 1998PASP..110.1259G) to include the prominent young and active stars
from those catalogues.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
tablea1.dat 105 456 All target stars from the present study
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See also:
J/ApJ/848/34 : CATalog of Stellar Unified Properties (Hinkel+, 2017)
Byte-by-byte Description of file: tablea1.dat
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Bytes Format Units Label Explanations
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1- 14 A14 --- Name Star name (TYCFFFF-NNNNN-N)
16 A1 --- f_Name [*+] Flag on Name (1)
18- 27 A10 --- OName Alternative name
29- 45 A17 --- SpType Spectral type (2)
47- 51 F5.2 [10-7W] logLX ? X-ray luminosity (2)
53- 57 F5.1 pc Dist Distance from Gaia DR2
59- 66 F8.2 min Texp On-source time
68- 73 F6.2 --- S/N Mean signal to noise ratio
75- 80 F6.2 d-1 EUV ? EUV flare rate calculated after
Audard et al. (2000ApJ...541..396A 2000ApJ...541..396A)
82- 85 F4.2 d-1 Ha ? Hα flare rate (see Section 4.1)
87- 93 F7.2 d-1 CMEul Observed upper limit of the CME rate
95- 99 F5.2 d-1 CMEme ? Maximum expected CME calculated after
Odert et al. (2020MNRAS.494.3766O 2020MNRAS.494.3766O)
101-105 F5.2 --- sig ? Standard deviation of the pseudo EWs of
the spectral time series of each star in
per cent
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Note (1): Flag as follows:
* = The origin of the data is the ESO phase 3 HARPS archive
+ = The origin of the data is the Polarbase archive
Note (2): Spectral types and logLX values are taken from Hinkel et al.
(2017ApJ...848...34H 2017ApJ...848...34H, Cat. J/ApJ/848/34), Gudel (2007LRSP....4....3G 2007LRSP....4....3G),
Gaidos (1998PASP..110.1259G 1998PASP..110.1259G), and Boller et al. (2016A&A...588A.103B 2016A&A...588A.103B,
Cat. J/A+A/588/A103)
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History:
From electronic version of the journal
(End) Ana Fiallos [CDS] 03-May-2023