07/07/2022 – Ephemeris – A closer look at the bright star Vega

This is Bob Moler with Ephemeris for Thursday, July 7th. Today the Sun will be up for 15 hours and 25 minutes, setting at 9:30, and it will rise tomorrow at 6:05. The Moon, 1 day past first quarter, will set at 1:53 tomorrow morning.

Vega, in the constellation Lyra the harp, is the highest star In the east and brightest star of the Summer Triangle also rising in that direction. It is an important and much studied star, first as a standard for brightness for the magnitude scale at almost exactly zero. It also has two fields of debris orbiting it. In 1983 the Infrared Astronomy Satellite, IRAS, discovered an excess of infrared radiation coming from the star. It seems now that there are two orbiting rings, one warm, and the other cold. This is somewhat like the two disks the Sun has: The asteroid belt between Mars and Jupiter and the Kuiper belt, beyond Neptune. No planets have yet been discovered around Vega, but I wouldn’t bet against it.

The astronomical event times given are for the Traverse City/Interlochen area of Michigan (EDT, UT – 4 hours). They may be different for your location.

Addendum

Animated Lyra finder chart. The lyre image not supplied by Stellarium but is from The World’s Earliest Music by Hermann Smith, Figure 60, A Project Gutenberg E-Book, and captioned “The Chelys or Greek Tortoiseshell Lyre”. Vega is the brightest star in Lyra, and the brightest star of the Summer Triangle. The other stars of the triangle are Deneb and Altair. Created using Stellarium.

Vega possesses two debris fields, similar to our own solar system’s asteroid and Kuiper belts. Astronomers continue to hunt for planets orbiting Vega, but as of May 2020 none have been confirmed. More info: bit.ly/VegaSystem Credit: NASA/JPL-Caltech