Super-slowly rotating Ap (ssrAp) stars sample Virtual Observatory Resource

Authors
  1. Hummerich S.
  2. Bernhard K.
  3. Paunzen E.
  4. Published by
    CDS
Abstract

The magnetic chemically peculiar Ap stars exhibit an extreme spread of rotational velocities, the cause of which is not clearly understood. Ap stars with rotation periods of 50 days or longer are know as super-slowly rotating Ap (ssrAp) stars. Photometrically variable Ap stars are commonly termed {alpha}^2^ Canum Venaticorum (ACV) variables. Our study aims to enlarge the sample of known ssrAp stars using data from the Zwicky Transient Facility (ZTF) survey to enable more robust and significant statistical studies of these objects. Using selection criteria based on the known characteristics of ACV variables, candidate stars were gleaned from the ZTF catalogues of periodic and suspected variable stars and from ZTF raw data. ssrAp stars were identified from this list via their characteristic photometric properties, {DELTA}a photometry, and spectral classification. The final sample consists of 70 new ssrAp stars, which mostly exhibit rotation periods of between 50 and 200 days. The object with the longest period has a rotation period of 2551.7 days. We present astrophysical parameters and a Hertzsprung-Russell diagram for the complete sample of known ssrAp stars. With very few exceptions, the ssrAp stars are grouped in the middle of the main sequence with ages in excess of 150Myr. ZTF J021309.72+582827.7 was identified as a possible binary star harbouring an Ap star and a cool component, possibly shrouded in dust. With our study, we enlarge the sample of known ssrAp stars by about 150%, paving the way for more in-depth statistical studies.

Keywords
  1. peculiar-variable-stars
  2. ap-stars
  3. photometry
  4. visible-astronomy
Bibliographic source Bibcode
2024A&A...692A.231H
See also HTML
https://cdsarc.cds.unistra.fr/viz-bin/cat/J/A+A/692/A231
IVOA Identifier IVOID
ivo://CDS.VizieR/J/A+A/692/A231

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https://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/A+A/692/A231
https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/A+A/692/A231
http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/A+A/692/A231
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https://vizier.iucaa.in/viz-bin/conesearch/J/A+A/692/A231/tablea1?
http://vizieridia.saao.ac.za/viz-bin/conesearch/J/A+A/692/A231/tablea1?
IVOA Cone Search SCS
For use with a cone search client (e.g., TOPCAT).
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https://vizier.iucaa.in/viz-bin/conesearch/J/A+A/692/A231/tablea2?
http://vizieridia.saao.ac.za/viz-bin/conesearch/J/A+A/692/A231/tablea2?

History

2025-07-23T10:39:38Z
Resource record created
2025-07-23T10:39:38Z
Created
2025-10-03T15:26:22Z
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