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August 18, 2014 - Galaxy Loses a Ring, Gains Two Arms

Galaxy Loses a Ring, Gains Two Arms Spiral galaxy M94 (also known as NGC 4736) is a familiar sight to both amateur and professional astronomers. Although it was long thought to feature two concentric rings, infrared observations by the Spitzer Space Telescope, supplemented with ultraviolet and optical data from other telescopes, has revealed that the faint outer “ring” is actually two immense spiral arms at the galaxy’s edge that appear as a single continuous ring. The bright ring around M94’s core is a true “starburst ring” where intense star formation is taking place. Between the inner ring and the outer arms lies the galaxy’s disk, a collection of tightly-wound spiral arcs of stars, dust, and gas. First observed in 1781, M94 lies 17 million light-years away in the constellation Canes Venatici.

Image credit: NASA / JPL-Caltech / SINGS Team

Weekly Calendar

August 18-24, 2014

Holidays - Sky Events - Space History

 

Moon phase Monday 18

Venus 0.2° north of Jupiter

1868: Total solar eclipse leads to discovery of helium
1877: Asaph Hall discovers Phobos
1960: Discoverer XIV launched, first successful US photo reconnaissance satellite
1993: First DC-X flight
1999: Cassini spacecraft flies by Earth

Moon phase Tuesday 19

1646: John Flamsteed born
1891: Milton Humason born
1982: Soyuz T-7 launched, Svetlana Savitskaya is second woman in space

Moon phase Wednesday 20

1953: First Redstone rocket launched
1960: Sputnik 5 launched
1975: Viking 1 launched
1977: Voyager 2 launched

Moon phase Thursday 21

1965: Gemini V launched
1972: OAO-3 launched
2002: First Atlas V rocket launched

Moon phase Friday 22

1963: X-15 sets world altitude record for a winged craft (354,000 feet)
1976: Luna 24 returns soil samples from Moon

Moon phase Saturday 23

Jupiter 5° north of Moon

Moon phase Sunday 24

Moon at apogee
Venus 6° north of Moon

 

 

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