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August 24, 2015 - A Star, But How Far?

A Star, But How Far?  The bright southern hemisphere star RS Puppis, at the center of the image, is swaddled in a gossamer cocoon of reflective dust illuminated by the glittering star. The super star is ten times more massive than our Sun and 200 times larger. RS Puppis rhythmically brightens and dims over a six-week cycle. It is one of the most luminous in the class of stars known as Cepheid variables. If it were as far away as the Sun, RS Puppis would appear 15,000 times brighter than the Sun. By observing the fluctuation of light in RS Puppis itself, as well as recording the faint reflections of light pulses that move across the nebula, astronomers are able to measure these light “echoes” and pin down a very accurate distance to the star. The distance to RS Puppis has been narrowed down to 6,500 light-years.

Image credit: NASA, ESA, and the Hubble Heritage Team (STScI / AURA) - Hubble / Europe Collaboration

Weekly Calendar

August 24-30, 2015

Holidays - Sky Events - Space History


Moon phase Monday 24

Moon phase Tuesday 25

1965: President Johnson approves full-scale development of Manned Orbital Laboratory
1966: Apollo-Saturn 202 launched
1981: Voyager 2 flies past Saturn
1989: Voyager 2 flies past Neptune
2003: Spitzer Space Telescope launched

Moon phase Wednesday 26

Jupiter in conjunction with Sun

Moon phase Thursday 27

1962: Mariner 2 launched
1984: Teacher In Space program announced
1985: STS-51I Discovery launched

Moon phase Friday 28

1789: William Herschel discovers Enceladus, moon of Saturn
1993: Galileo spacecraft flies by asteroid Ida
2009: STS-128 Discovery launched

Moon phase Saturday 29

Venus 9° south of Mars
Full Moon 2:35 PM ET
Neptune 3° south of Moon

Moon phase Sunday 30

Moon at perigee

1963: Lunar Orbiter program approved by NASA
1983: STS-8 Challenger launched
1984: STS-41D Discovery launched

Suggestions for new history dates or better links? Corrections for errors on this page? Please e-mail me.