Starwatch for July 2019
Written by Karl Hricko on July 9, 2019
Hello! I’m Karl Hricko of United Astronomy Clubs of NJ and the National Space Society, bringing you the July Starwatch for the WNTI listening area.
A giant firework went off in the sky. On July 4th in 1054 A.D Chinese recorded it as a “Guest Star”. It may have also been depicted in a petroglyph in Chaco Canyon, N.M. by Native Americans. It was a supernova that could be seen in daylight for 23 days. This type II supernova is a result of an unstable massive star collapsing into a neutron star.
The gaseous remnant of this exploded star was first catalogued by Charles Messier as M1 in 1758. It was later drawn and named “The Crab Nebula” in 1844 by William Parsons (Third Earl of Rosse). In 1968, Richard Lovelace discovered a remnant star in the middle of the Crab Nebula, and identified it as a pulsar, or a rapidly rotating neutron star.
Since the Crab Nebula is 6,500 light years away, it took those many years for the supernova explosion to be seen in 1054. Although the Crab Nebula can only be seen with telescope or binoculars, there are still 5 planets ordinarily visible to the naked eye. Unfortunately, Mercury, Mars, and Venus are too low on the horizon to be seen this month. However, at dusk, Jupiter can still be seen southeast in Ophiuchus. Looking in the same direction at the same time, Saturn is in Sagittarius.
So besides a display of terrestrial fireworks, our day of independence has been marked by a major heavenly firework–called a supernova.
Until our next Starwatch – Don’t forget to check out …What’s up in the night sky!