Volume 404, Number 1, June II 2003
|Page(s)||305 - 315|
|Section||Stellar structure and evolution|
|Published online||26 May 2003|
Photometry and low resolution spectroscopy of hot post-AGB candidates
Indian Institute of Astrophysics, Koramangala, Bangalore 560034, India
2 State Observatory, Manora Peak, Nainital 263129 (Uttaranchal), India
Corresponding author: G. Gauba, firstname.lastname@example.org
Accepted: 7 March 2003
We have obtained Johnson U, B, V and Cousins R, I photometry and low resolution spectra of a small sample of hot post-AGB candidates. Using the present data in combination with JHK data from 2MASS, infrared data from the MSX catalog and the IRAS fluxes, we have studied the spectral energy distribution (SED) of these stars. Using the DUSTY code we have estimated the dust temperatures, the distances to the stars, the mass-loss rates, angular radii of the inner boundary of the dust envelopes and dynamical ages from the tip of the AGB. These candidates have also been imaged through a narrow band Hα filter, to search for nebulosity around the central stars. Our Hα images revealed the bipolar morphology of the low excitation PN IRAS 17395–0841 with an angular extent of 2.8´´. The bipolar lobes of IRAS 17423–1755 in Hα were found to have an angular extent of 3.5´´ (south-east lobe) and 2.2´´ (north-west lobe). The dust envelope characteristics, low resolution spectrum and IRAS colors suggest that IRAS 18313–1738 is similar to the proto-planetary nebula (PPN) HD 51585. The SED of IRAS 17423–1755, IRAS 18313–1738 and IRAS 19127+1717 show a warm dust component (in addition to the cold dust) which may be due to recent and ongoing mass-loss.
Key words: stars: AGB and post-AGB / stars: early-type / stars: evolution / stars: mass-loss / stars: circumstellar matter
© ESO, 2003
Current usage metrics show cumulative count of Article Views (full-text article views including HTML views, PDF and ePub downloads, according to the available data) and Abstracts Views on Vision4Press platform.
Data correspond to usage on the plateform after 2015. The current usage metrics is available 48-96 hours after online publication and is updated daily on week days.
Initial download of the metrics may take a while.