A windswept cometary tail on the galactic center supergiant 1RS 7

F. Yusef-Zadeh*, Mark Morris

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

51 Scopus citations


High-resolution VLA observations provide evidence of optically thick radio continuum emission from 1RS 7, a cool red supergiant star, located at a projected distance of ≈1 lt-yr from the Galactic center. 1RS 7 shows a remarkable "tail" of ionized gas pointing directly away from the compact nonthermal radio source at the Galactic center, Sgr A*. Given previous evidence for a strong source of UV emission and for a strong circumnuclear wind emanating from the Galactic center, the free-free emission from 1RS 7 and its associated "tail" are interpreted in terms of the ionization and removal of the circumstellar envelope of the red supergiant either by the ram pressure of the nuclear wind or by the pressure of radiation arising from the immediate vicinity of Sgr A*. The wind mechanism is preferred because (1) the force it can potentially exert is much greater and (2) Sgr A* is clearly not a known source of luminous energy in the near-IR, whereas it remains a plausible source of a hot, high-velocity wind. Also considered is the potential effect of a nuclear wind upon the atmospheres of red giants in the inner parsec.

Original languageEnglish (US)
Pages (from-to)L59-L62
JournalAstrophysical Journal
Issue number2 PART 2
StatePublished - Apr 20 1991


  • Galaxies: The Galaxy
  • Stars: supergiants
  • Stars: winds

ASJC Scopus subject areas

  • Astronomy and Astrophysics
  • Space and Planetary Science


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