High resolution spectroscopy of the post-red supergiant IRC+10420. I. The data
Abstract
A high resolution optical spectrum of the post-red supergiant candidate IRC+10420 is presented. The Utrecht Echelle Spectrograph observations, with a total integration time of more than 9 hours, provide a spectral coverage from 3850 Angstroms to 1 mu m, and a spectral resolution of 9 km s(-1) . The spectrum is shown, and an identification list of lines in the spectrum is provided. From a preliminary analysis of the spectrum we find that the spectral type of IRC+10420 has changed from F8I{(+}) in 1973 to mid- to early A type now, confirming the results of \cite[Oudmaijer et al. (1996)]{ou96}, who claimed a change in temperature based on photometric changes. It is shown that most of the emission lines in the spectrum of IRC+10420 are blue-shifted with respect to the systemic velocity traced by circumstellar rotational CO emission, while the (few) absorption lines - with the exception of some high excitation lines - are red-shifted by 25 km s(-1) , which may suggest infall of material onto the star. Finally, it is found that the interstellar extinction towards IRC+10420 , as traced by the Diffuse Interstellar Bands is very large, with an inferred E(B-V) of 1.4 +/- 0.5 compared to a total E(B-V) of 2.4. Table B1 is only available at the CDS via anonymous ftp 130.79.128.5 or at http://cdsweb.u-strasbg.fr/Abstract.html
- Publication:
-
Astronomy and Astrophysics Supplement Series
- Pub Date:
- May 1998
- DOI:
- 10.1051/aas:1998404
- Bibcode:
- 1998A&AS..129..541O
- Keywords:
-
- STARS: CIRCUMSTELLAR MATTER;
- STARS: EMISSION-LINE;
- BE;
- STARS: INDIVIDUAL: IRC+10420;
- STARS: AGB AND POST-AGB;
- STARS: SUPERGIANTS