September 28
The Ghost's Lantern
Sun Position
The Sun is in Libra near -4° declination. Evenings are growing distinctly cooler in the Northern Hemisphere; Southern Hemisphere observers are experiencing warmer, longer spring evenings.
Sky Highlight
The Andromeda constellation and its associated galaxies are excellently placed this week, and deep-sky observers using dark skies and averted vision can attempt NGC 404 (Mirach's Ghost) a faint elliptical galaxy visually contaminated by Mirach's glare. It requires careful eyepiece technique and a dark site.
Deep Sky Object
NGC 404, Mirach's Ghost, Andromeda. A lenticular galaxy about 10 million light-years away, NGC 404 sits so close to Mirach on the sky that Mirach's bright light overwhelms it in most eyepieces. It is one of the closest known lenticular galaxies and an unusual object in that it shows a ring of recent star formation unexpected in this galaxy type.
Featured Star
Mirach (β And) is a red giant of spectral type M0IIIab, about 197 light-years away, one of the brighter and more accessible red giants in the autumn sky. It is also the key navigation star to M31 and M33, two-and-a-half degrees north and slightly west of Mirach leads directly to the Andromeda Galaxy's core.
Around This Date
- September 28, 2015NASA held a press conference announcing the detection of hydrated perchlorate salts in recurring slope lineae on Mars, providing the strongest evidence yet for contemporary liquid water activity on the planet.
- September 29, 1988The Space Shuttle Discovery (STS-26) launched, returning the US to human spaceflight 32 months after the Challenger accident, the first crewed launch since January 28, 1986.
Mirach has a ghost, a galaxy so close in angle that it hides in the star's spillover light, and finding it requires patience and a steady eye.