In a holiday image courtesy of the Hubble Space Telescope, the Cepheid variable star RS Puppis, 10 times more massive than the sun and 200 times larger, shines in a wreath-like “gossamer cocoon” of dust, brightening and dimming over a 41.5-day cycle. RS Puppis has an average intrinsic brightness 15,000 times greater than the Sun’s and is one of the most luminous Cepheids in the Milky Way. As it pulsates, the surrounding nebula flashes in wave like “light echoes. By measuring those fluctuations and the faint light echoes moving across the nebula, astronomers have been able to establish the distance to RS Puppis with high precision. The European Southern Observatory’s New Technology Telescope found that distance to be about 6,500 light years in 2008. Follow-on studies by Hubble in 2014 came up with a slightly lower value. The European Space Agency’s Gaia spacecraft was able to directly measure the distance to RS Puppis using geometric parallax, coming up with a value of 5,580 (plus or minus 260) light years.
A planet discovered last year sitting at an unusually large distance from its star — 16 times farther than Pluto is from the Sun — may have been kicked out of its birthplace close to the star in a process similar to what may have happened early in our own solar system’s history. The planet’s 13-million-year-old parent star is known as HD 106906 and lies 300 light-years away.
At a ceremony held today in Germany, the European Southern Observatory and the ACe Consortium signed the largest contract ever in ground-based astronomy for key components of the 39-metre aperture European Extremely Large Telescope (E-ELT). The 85-metre-diameter, 5000 tonne dome and telescope structure will take telescope engineering into new territory.