Astronomy and Astrophysics – Astrophysics – Solar and Stellar Astrophysics
Scientific paper
2009-02-10
Astronomy and Astrophysics
Astrophysics
Solar and Stellar Astrophysics
19 pages, 16 figures. Astronomy and Astrophysics (2009) In press
Scientific paper
[Abridged] - Context: Circumstellar envelopes (CSEs) around Cepheids are particularly interesting as they could impact the Cepheid distance scale, and imply stellar mass loss. Aims: Our goal is to establish the spatial and spectral properties of the CSEs of L Car and RS Pup. This is done through a parametrization of the envelopes in terms of fractional flux (with respect to the star) and angular size. - Methods: We retrieved archival Spitzer images of the two stars (3.5-70 mic), and obtained new imaging with the VLT/VISIR camera in BURST mode (8.6-11.9 mic), as well as interferometry with VLTI/MIDI (8-13 mic). This combination allows us to probe the envelopes over arcminute to milliarcsecond scales. - Results: The CSE of RS Pup is resolved at 24 and 70 mic by Spitzer, and around 10 mic by MIDI and VISIR. The compact envelope of L Car is resolved only in the VISIR and MIDI observations. However, the properties of the IR excesses differ considerably : a warm component is present around both stars at a spatial scale of a few 100 to a few 1 000 AU, but RS Pup presents in addition a large (several 100 000 AU) and cold (~40 K) dusty envelope. - Conclusions: We propose that the reflection nebula surrounding RS Pup has an interstellar origin, while the warm CSEs of both stars were created by ongoing stellar mass loss. Such warm circumstellar envelopes are probably common around Cepheids.
Gallenne Alexandre
Kervella Pierre
Mérand Antoine
No associations
LandOfFree
The circumstellar envelopes of the Cepheids L Car and RS Pup - Comparative study in the infrared with Spitzer, VLT/VISIR and VLTI/MIDI does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.
If you have personal experience with The circumstellar envelopes of the Cepheids L Car and RS Pup - Comparative study in the infrared with Spitzer, VLT/VISIR and VLTI/MIDI, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and The circumstellar envelopes of the Cepheids L Car and RS Pup - Comparative study in the infrared with Spitzer, VLT/VISIR and VLTI/MIDI will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-19680