The Mass-loss History of the Red Hypergiant VY CMa

Journal Article · Mon Mar 01 04:00:00 EST 2021 · The Astronomical Journal (Online)

DOI:https://doi.org/10.3847/1538-3881/ABD316· OSTI ID:23159163

Humphreys, Roberta M.; Davidson, Kris; Jones, Terry J. ^[1]; Richards, A. M. S. ^[2]; Ziurys, L. M. ^[3]; Ishibashi, Kazunori ^[4]

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1. Minnesota Institute for Astrophysics, University of Minnesota, Minneapolis, MN 55455 (United States)
2. Jodrell Bank, Department of Physics and Astronomy, University of Manchester (United Kingdom)
3. Departments of Astronomy and Chemistry, University of Arizona (United States)
4. Graduate School of Science, Nagoya University, Nagoya, 464-8602 (Japan)

Imaging and spectroscopy of the knots, clumps, and extended arcs in the complex ejecta of VY CMa confirm a record of high mass-loss events over the past few hundred years. Hubble Space Telescope/Space Telescope Imaging Spectrograph spectroscopy of numerous small knots close to the star allow us to measure their radial velocities from the strong K i emission and determine their separate motions, spatial orientations, and time since ejecta. Their ages concentrate around 70, 120, 200, and 250 yr ago. A K i emission knot only 50 mas from the star ejected as recently as 1985–1995 may coincide with an H{sub 2}O maser. Comparison with VY CMa’s historic light curve from 1800 to the present shows several knots with ejection times that correspond with extended periods of variability and deep minima. The similarity of this correspondence in VY CMa with the remarkable recent dimming of Betelgeuse and an outflow of gas is apparent. The evidence for similar outflows from the surface of a more typical red supergiant suggests that discrete ejections are more common and surface or convective activity is a major source of mass loss for red supergiants.

• OSTI ID: 23159163
• Journal Information: The Astronomical Journal (Online), Journal Name: The Astronomical Journal (Online) Journal Issue: 3 Vol. 161; ISSN 1538-3881
• Country of Publication: United States
• Language: English

Related Subjects

46 INSTRUMENTATION RELATED TO NUCLEAR SCIENCE AND TECHNOLOGY
79 ASTRONOMY AND ASTROPHYSICS
EMISSION
MASERS
MASS TRANSFER
ORIENTATION
RADIAL VELOCITY
SPECTROSCOPY
STARS
STELLAR WINDS
SURFACES
TELESCOPES