IRAS 00450+7401 and the Mid-infrared Fade/Burst Cycle of R Coronae Borealis-type Stars
Journal article, 2023

We present optical and infrared imaging and spectroscopy of the R Coronae Borealis-type (R Cor Bor) star IRAS 00450+7401. Optical spectra further confirm its classification as a cool R Cor Bor system, having a hydrogen-deficient carbon star spectral subclass of HdC5 or later. Mid-infrared spectroscopy reveals the typical ∼8 μm “hump” seen in other R Cor Bor stars and no other features. A modern-epoch spectral energy distribution shows bright emission from hot dust having T dust > 600 K. Historical infrared data reveal generally cooler dust color temperatures combined with long-term fading trends, but provide no discernible correlation between flux level and temperature. Investigating the most mid-infrared variable R Cor Bor stars found in IRAS, AKARI, and WISE data reveals similar fading trends, bursts that can show a factor of up to 10 change in flux density between epochs, and blackbody-fit dust color temperatures that span 400-1300 K. While some R Cor Bor stars such as IRAS 00450+7401 appear to undergo fade/burst cycles in the mid-infrared, significant gaps in temporal coverage prevent conclusively identifying any preferred timescale for their mid-infrared variability and circumstellar dust temperature changes.

Author

William A. Burris

San Diego State University

C. Melis

Center for Astrophysics & Space Sciences

Allen W. Shafter

San Diego State University

Georgia Panopoulou

Chalmers, Space, Earth and Environment, Astronomy and Plasmaphysics

E. L. Wright

University of California

John Della Costa

San Diego State University

Astronomical Journal

0004-6256 (ISSN) 1538-3881 (eISSN)

Vol. 166 2 40

Subject Categories

Astronomy, Astrophysics and Cosmology

Atom and Molecular Physics and Optics

Other Electrical Engineering, Electronic Engineering, Information Engineering

DOI

10.3847/1538-3881/acda93

More information

Latest update

7/26/2023