Daily Archives: September 9, 2013

Sun online. Solar activity. 09 September 2013

According to the data of Royal Observatory of Belgium:
Solar activity has been very low, no C-class flares in past 48h, no changes are foreseen. There is a small coronal hole currently in geoeffective position but, due to its size, it will most likely not produce any disturbance. Geomagnetic conditions have been quiet and are expected to remain so.

Local time:9/9/2013 at 9:20:05Local time:9/9/2013 at 9:20:05 Local time:9/9/2013 at 9:20:05Local time:9/9/2013 at 9:20:05

Equipment: Coronado 90 + SBIG 8300s + LX75
Editor: Photoshop
Date: 09/09/13
Time GMT: 19:30:00
Exposure 0.09 sec.

With SPONLI Space is getting closer!

Nearby Cepheid Variable RS Pup

Image Credit: Hubble Legacy Archive, NASA, ESA – Processing: Stephen Byrne
Explanation: It is one of the most important stars in the sky. This is partly because, by coincidence, it is surrounded by a dazzling reflection nebula. Pulsating RS Puppis, the brightest star in the image center, is some ten times more massive than our Sun and on average 15,000 times more luminous. In fact, RS Pup is a Cepheid type variable star, a class of stars whose brightness is used to estimate distances to nearby galaxies as one of the first steps in establishing the cosmic distance scale. As RS Pup pulsates over a period of about 40 days, its regular changes in brightness are also seen along the nebula delayed in time, effectively a light echo. Using measurements of the time delay and angular size of the nebula, the known speed of light allows astronomers to geometrically determine the distance to RS Pup to be 6,500 light-years, with a remarkably small error of plus or minus 90 light-years. An impressive achievement for stellar astronomy, the echo-measured distance also more accurately establishes the true brightness of RS Pup, and by extension other Cepheid stars, improving the knowledge of distances to galaxies beyond the Milky Way. The above image was taken by the Hubble Space Telescope and digitally processed by a volunteer.