Hubblesite.org has released a video with the highlights of the night sky in October. They include:
NGC 1569, photo: Hubble Site - NASA / A. Aloisi (STScI/ESA) et al.
NGC 1569 is a dwarf irregular galaxy found in the Camelopardalis constellation. It is one of the best known starburst galaxies in the sky. It was first discovered by William Herschel on November 4, 1788. NGC 1569 has an apparent visual magnitude of 11.9 lies at a distance of 11 million light years.
The galaxy’s spectrum is blueshifted, which means that NGC 1569 is moving toward our solar system, unlike most other galaxies, which have redshifted spectra and are therefore moving away from us (because the universe is expanding).
NGC 1569 is undergoing a burst of star formation, one more intense than in any other galaxy in the Local Group. The star forming activity in NGC 1569 is believed to have begun more than 25 million years ago. Even though the rate at which new stars are formed in the galaxy has declined in the last 10 million years, it is still quite high.
The starburst activity is believed to be so intense because NGC 1569 lies in the middle of a group of galaxies centered on the spiral galaxy IC 342, and the gravitational interactions are causing the gas in NGC 1569 to compress, which in turn is causing such furious starburst activity within the galaxy.
NGC 1569 is also notable for the massive star clusters discovered in it, each containing over a million stars.
The galaxy is believed to lie close to the Local Group of galaxies. Its coordinates in the sky are 4h 30 m 49.1s (right ascension), +64°50’53” (declination).
HubbleSite.org has released a video with the June night sky highlights: the evening and morning planets, summer constellations, star clusters, brightest stars and a partial solar eclipse on June 1. Watch the clip below.
EVENING & MORNING PLANETS
CONSTELLATIONS
Continue reading “The night sky in June”
Boötes Dwarf Galaxy (with falsely coloured stars), photo: V Belokurov, IoA Cambridge, Sloan Digital Sky Survey
Boötes I is a rather faint galaxy. It has an apparent visual magnitude of 13.1 and an absolute magnitude of -5.8. The galaxy’s luminosity is only 100,000 times that of the Sun.
It is one of the least luminous galaxies ever discovered. In fact, when it was discovered in 2006, it was the single least luminous galaxy ever seen, beating the previous record holder, an extremely dim galaxy in the constellation Ursa Minor.
The Boötes Dwarf is also one of the Milky Way’s most remote companion galaxies.
Boötes I is a dwarf spheroidal galaxy that seems to be tidally disrupted by our own galaxy, the Milky Way, which it orbits.
It is a metal and gas-poor galaxy. Its stars are spread out from one another and they look like stars in a very old globular cluster, suggesting that the galaxy itself is ancient.
NGC 1679, photo: NASA/ESA (Wikisky)
The galaxy is faint and pretty difficult to observe, with an apparent visual magnitude of 11.6.
It lies two degrees away from the star Zeta Caeli, an orange subgiant with an apparent magnitude of 6.35.
The galaxy’s coordinates are 04h 49m 55.4s (right ascension) and -31°58’03” (declination).
Constellation Guide