Variability in Proto-Planetary Nebulae: VIII. A New Sample of Southern Hemisphere Objects

Abstract

As part of our continuing study of light variability in proto-planetary nebulae (PPNe), we present the results from a long-term study of nine southern hemisphere objects. We have monitored their light variations over a nine-year interval from 2010-2018. These were supplemented by data from the ASAS-SN and ASAS-3 surveys, leading to combined light curves from 2000 to 2020. Pulsation periods were found in seven of the objects, although the three shortest must be regarded as tentative. The periods range from 24 to 73 days. When compared with the results of previous studies of the light variations in PPNe, we find that they show the same trends of shorter period and smaller light variations with higher temperatures. Luminosities were calculated based on the spectral energy distributions, reddening, and Gaia distances, and these confirm the identification of all but one as post-AGB objects. Three of the stars possess long-period variations of 5 to 19 years. These are most likely due to the periodic obscuration of the star by a disk, suggesting the presence of a binary companion and a circumbinary disk.

27 pages, 6 tables, 8 figures. Accepted Sep 1, 2021 for publication in the Astronomical Journal: revised in attempt to correct pdf file

References in corpus (14)

• Estimating distances from parallaxes. V: Geometric and photogeometric distances to 1.47 billion stars in Gaia Early Data Release 3
• The All-Sky Automated Survey for Supernovae (ASAS-SN) Light Curve Server v1.0
• Three-dimensional mapping of the local interstellar medium with composite data
• A spectroscopic atlas of post-AGB stars and planetary nebulae selected from the IRAS Point Source Catalogue
• An evolutionary catalogue of Galactic post-AGB and related objects
• Optically visible post-AGB/RGB stars and young stellar objects in the Small Magellanic Cloud: candidate selection, spectral energy distributions and spectroscopic examination
• New light on Galactic post-asymptotic giant branch stars. I. First distance catalogue
• The Remote Observatories of the Southeastern Association for Research in Astronomy (SARA)
• Binarity as the Origin of Long Secondary Periods in Red Giant Stars
• PAH Formation in O-rich Planetary Nebulae
• An all-sky catalog of solar-type dwarfs for exoplanetary transit surveys
• Where Are the Binaries? Results of a Long-Term Search for Radial Velocity Binaries in Proto-Planetary Nebulae
• 30-micron sources in galaxies with different metallicities
• Variability in Proto-Planetary Nebulae: VI. Multi-Telescope Light Curves Studies of Several Medium-Bright (V=13-15), Carbon-Rich Objects

Cited by in corpus (1)

• Luminosities and masses of single Galactic Post-Asymptotic Giant Branch (Post-AGB) stars with distances from $Gaia$ EDR3: The revelation of an $s$-process diversity