Cometary Astropause of Mira Revealed in the Far-Infrared

Abstract

Evolved mass-losing stars such as Mira enrich the interstellar medium (ISM) significantly by their dust-rich molecular wind. When these stars move fast enough relative to the ISM, the interaction between the wind and ISM generates the structure known as the astropause (a stellar analog of the heliopause), which is a cometary stellar wind cavity bounded by the contact discontinuity surface between the wind and ISM. Far-infrared observations of Mira spatially resolve the structure of its astropause for the first time, distinguishing the contact surface between Mira's wind and the ISM and the termination shock due to Mira's wind colliding with the ISM. The physical size of the astropause and the estimated speed of the termination shock suggest the age of the astropause to be about 40,000 yr, confirming a theoretical prediction of the shock re-establishment time after Mira has entered the Local Bubble.

arXiv comment9 pages including 2 figures. To appear in the Astrophysical Journal Letters

References in corpus (11)

• The Spitzer Space Telescope Mission
• Infrared Emission from Interstellar Dust. IV. The Silicate-Graphite-PAH Model in the Post-Spitzer Era
• Local stellar kinematics from Hipparcos data
• The Infrared Astronomical Mission AKARI
• SWIRE: The SIRTF Wide-area InfraRed Extragalactic Survey
• Reduction Algorithms for the Multiband Imaging Photometer for Spitzer
• Reprocessing the Hipparcos data for evolved stars III Revised Hipparcos period-luminosity relationship for galactic long-period variable stars
• Detection of a Far-Infrared Bow-Shock Nebula Around R Hya: the First MIRIAD Results
• It's a wonderful tail: the mass loss history of Mira
• Discovery of an HI Counterpart to the Extended Tail of Mira
• Modelling CO emission from Mira's wind

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• Herschel's view into Mira's head
• The Interaction of Asymptotic Giant Branch Stars with the Interstellar Medium
• 870 um observations of evolved stars with LABOCA
• X Her and TX Psc: Two cases of ISM interaction with stellar winds observed by Herschel
• HI Observations of the Asymptotic Giant Branch Star X Herculis: Discovery of an Extended Circumstellar Wake Superposed on a Compact High-Velocity Cloud
• A model of Mira's cometary head/tail entering the Local Bubble
• An HI Imaging Survey of Asymptotic Giant Branch Stars
• The interface between the stellar wind and interstellar medium around R Cassiopeiae revealed by far-infrared imaging
• The astrosphere of the Asymptotic Giant Branch star CIT 6
• Discovery of a halo around the Helix Nebula NGC 7293 in the WISE all-sky survey
• The rebrightening of planetary nebulae through ISM interaction
• Morphology and kinematics of the gas envelope of Mira Ceti
• A Review of AGB Mass Loss Imaging Techniques
• Revealing new features of the millimetre emission of the circumbinary envelope of Mira Ceti
• Mira Ceti, atypical archetype
• Faint but not forgotten. I. First results from a search for astrospheres around AGB stars in the far-ultraviolet
• MHD flows at astropauses and in astrotails