Astronomy Picture of the Day
Discover the cosmos! Each day a different image or photograph of our fascinating universe is featured, along with a brief explanation written by a professional astronomer.
2003 July 18 
Posted on 07/17/2003 9:34:53 PM PDT by petuniasevan
Discover the cosmos! Each day a different image or photograph of our fascinating universe is featured, along with a brief explanation written by a professional astronomer.
2003 July 18
Explanation: A planet, a white dwarf, and a neutron star orbit each other in the giant globular star cluster M4, some 5,600 light-years away. The most visible member of the trio is the white dwarf star, indicated above in an image from the Hubble Space Telescope, while the neutron star is detected at radio frequencies as a pulsar. A third body was known to be present in the pulsar/white dwarf system and a detailed analysis of the Hubble data has indicated it is indeed a planet with about 2.5 times the mass of Jupiter. In such a system, the planet is likely to be about 13 billion years old. Compared to our solar system's tender 4.5 billion years and other identified planets of nearby stars, this truly ancient world is by far the oldest planet known, almost as old as the Universe itself. Its discovery as part of an evolved cosmic trio suggests that planet formation spans the age of the Universe and that this newly discovered planet is likely only one of many formed in the crowded environs of globular star clusters.
Globular Cluster M4
NOAO/AURA/NSF Photo
| Right Ascension | 16 : 23.6 (h:m) |
|---|---|
| Declination | -26 : 32 (deg:m) |
| Distance | 7.2 (kly) |
| Visual Brightness | 5.6 (mag) |
| Apparent Dimension | 26.3 (arc min) |
Question to ponder: How did a planet survive the supernova that produced the pulsar?
Hopefully I'll add to the pages this weekend.
Disclaimer: Opinions posted on Free Republic are those of the individual posters and do not necessarily represent the opinion of Free Republic or its management. All materials posted herein are protected by copyright law and the exemption for fair use of copyrighted works.
