Contents
Images
Upload your image
DSS Images Other Images
Related articles
The Hvar survey for roAp stars. I. The survey observations
Context. The rapidly oscillating Ap (roAp) stars exhibit short timescale photometric and/or radial velocity variations, which are mostimportant to test current pulsation models as well as our assumptions ofthe atmospheric structure characteristics. In addition, their chemicalpeculiarity makes them very interesting for probing stellar formationand evolution in the presence of a global magnetic field. To date, onlya limited number of about 45 roAp stars are known. Aims: In orderto increase the sample, we obtained photometric time series of 20 goodroAp candidates to search for pulsations. Methods: We present thetime series analysis of about 60 h of CCD photometry taken at the 1 mAustrian-Croatian Telescope (Hvar Observatory) and derive effectivetemperatures for the programme objects. Results: The upperamplitude limits of the Fourier spectra are typically below 2 mmag inBessell B with one good candidate for follow-up observations to findpossible pulsation. In addition, we present a list of further roApcandidates, worth to be (re)investigated.The reduced photometric data are only available at the CDS via anonymousftp to cdsarc.u-strasbg.fr (130.79.128.5) or via http://cdsarc.u-strasbg.fr/viz-bin/qcat?J/A+A/542/A89
| Catalogue of Ap, HgMn and Am stars
We present a catalogue of 8205 known or suspected Ap, HgMn and Am stars.This paper is a major update of our first edition of the catalog of Apand Am stars and includes revised identifications, additional stars andrevised information obtained from the literature.Catalogue (full Table 1) is only available in electronic form at the CDSvia anonymous ftp to cdsarc.u-strasbg.fr (130.79.128.5) or viahttp://cdsweb.u-strasbg.fr/cgi-bin/qcat?J/A+A/498/961
| Catalogue of CP stars with references to short time scale variability
A catalogue was compiled which contains all references in the literaturesince 1962 related to variations of CP stars on time scales shorter thanthe rotation period. The role of this catalogue lies in the unbiasedlisting of all available references, and not in a critical evaluation.
| A seven-year northern sky survey of AP stars for rapid variability
A high-speed photometric survey of 120 Ap stars in the northern sky, hasbeen conducted, between 1985 and 1991, in order to search for rapidvariability. Stars of spectral types, namely from B8 to F4, have beenselected for the survey. The selected pulsational variable stars occupythe hotter regions of the instability strip of the Hertzsprung-Russeldiagram. Noted is the absence of pulsations in the hotter B8-A3 Apstars; this does not, however, preclude the existence of pulsations,since HD 218495 was recently discovered to be a rapidly oscillating Ap(roAp) star. The primary result of this study is that variouscombinations of photometric indices, while pointing towards roAp starshaving the characteristic signatures of cool, SrCrEu stars, still failto isolate the roAp phenomenon from similar nonpulsating Ap stars.Color-magnitude and color-color diagrams are presented in order tocomplete this survey.
| General catalogue of AP and AM stars
A catalog of all the known Ap and Am stars, containing a total of 6684objects, was prepared. The few stars that were wrongly considered as Apor Am star are noted as well as some others for which their identity asAp or Am stars is not yet well established. The catalog gives theidentificators and the main observational data for each star, includingthe magnitude, color, spectral type, duplicity, periodicity, magneticfield, and projected rotational velocity.
| Lists of photometric AM candidates
The Geneva photometric m parameter (Nicolet and Cramer, 1982) is used inorder to select Am photometric candidates from the Rufener (1981)catalogue. Two lists are given, the first containing field stars and thesecond cluster stars. According to the photometric criteria thediffusion process probably responsible for the Am phenomenon takes placerather quickly as Am candidates are present in young clusters. It isconfirmed that the phenomenon is enhanced by low rotational velocity andhigh metallicity. The age seems to slightly affect the Am phenomenon.
| Multicolor photometry of metallic-line stars. III. A photometric catalogue
Abstract image available at:http://adsabs.harvard.edu/cgi-bin/nph-bib_query?1974RMxAA...1..175M&db_key=AST
| Catalogue et bibliographie des étoiles A à spectre particulier
Not Available
|
Submit a new article
Related links
Submit a new link
Member of following groups:
|
Observation and Astrometry data
| Constellation: | Hercule |
| Right ascension: | 17h46m42.30s |
| Declination: | +27°58'59.1" |
| Apparent magnitude: | 8.994 |
| Proper motion RA: | -0.1 |
| Proper motion Dec: | -1.4 |
| B-T magnitude: | 9.424 |
| V-T magnitude: | 9.03 |
Catalogs and designations:
|
