Sun and HD128621 spectra Virtual Observatory Resource

Authors
  1. Al Moulla K.
  2. Dumusque X.
  3. Cretignier M.
  4. Zhao Y.
  5. Valenti J.A.
  6. Published by
    CDS
Abstract

To enable radial velocity (RV) precision on the order of ~0.1m/s required for the detection of Earth-like exoplanets orbiting solar-type stars, the main obstacle lies in mitigating the impact of stellar activity. This study investigates the dependence of derived RVs with respect to the formation temperature of spectral line segments. Using spectral synthesis, we compute for each observed wavelength point of unblended spectral lines the stellar temperature below which 50% of the emergent flux originates. We can then construct RV time series for different temperature ranges, using template matching. With HARPS-N solar data and HARPS alpha Cen B measurements, we demonstrate on time intervals of prominent stellar activity that the activity-induced RV signal has different amplitude and periodicity depending on the temperature range considered. We compare the solar measurements with simulated contributions from active surface regions seen in simultaneous images, and find that the suppression of convective motion is the dominant effect. From a carefully selected set of spectral lines, we are able to measure the RV impact of stellar activity at various stellar temperatures ranges. We are able to strongly correlate the effect of convective suppression with spectral line segments formed in hotter temperature ranges. At cooler temperatures, the derived RVs exhibit oppositely directed variations compared to the average RV time series and stronger anti- correlations with chromospheric emission.

Keywords
  1. the-sun
  2. spectroscopy
  3. visible-astronomy
Bibliographic source Bibcode
2022A&A...664A..34A
See also HTML
https://cdsarc.cds.unistra.fr/viz-bin/cat/J/A+A/664/A34
IVOA Identifier IVOID
ivo://CDS.VizieR/J/A+A/664/A34
Document Object Identifer DOI
doi:10.26093/cds/vizier.36640034

Access

Web browser access HTML
https://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/A+A/664/A34
https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/A+A/664/A34
http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/A+A/664/A34
IVOA Table Access TAP
https://tapvizier.cds.unistra.fr/TAPVizieR/tap
Run SQL-like queries with TAP-enabled clients (e.g., TOPCAT).
Web browser access HTML
https://cdsarc.cds.unistra.fr/assocdata/?obs_collection=J/A+A/664/A34

History

2022-08-04T08:44:56Z
Resource record created
2022-08-04T08:44:56Z
Created
2022-11-13T17:32:21Z
Updated

Contact

Name
CDS support team
Postal Address
CDS, Observatoire de Strasbourg, 11 rue de l'Universite, F-67000 Strasbourg, France
E-Mail
cds-question@unistra.fr