2003 Ub 313: The Incredible Shrinking Planet?, No bigger than Pluto? |
2003 Ub 313: The Incredible Shrinking Planet?, No bigger than Pluto? |
Guest_BruceMoomaw_* |
Jan 31 2006, 09:20 PM
Post
#1
|
Guests |
|
|
|
Apr 12 2006, 05:15 AM
Post
#2
|
|
Junior Member Group: Members Posts: 37 Joined: 21-December 05 Member No.: 614 |
QUOTE The problem is that it's easy to say that now with just one solar system and nine (or eight or ten, depending on who's counting) planets. What happens when we start finding solar systems where the equivalent of Mercury is the size of Europa or Triton? Is the response of astronomers to be: Sorry, you have to be "this big" to qualify as a planet. For some reason the exoplanets in the PSR 1257+12 system never get a lot of attention, yet they are as small or even smaller as Pluto. Did we discover small planets or are they the first asteroids/minor planets we found around another star? |
|
|
Apr 12 2006, 05:45 AM
Post
#3
|
|
Member Group: Members Posts: 249 Joined: 11-June 05 From: Finland (62°14′N 25°44′E) Member No.: 408 |
PSR 1257+12 B and C are a few times more massive than the Earth, A is about the size of the Moon. There's probably yet another body, but not even the discoverers call it a planet as it is has only one fifth the mass of Pluto.
-------------------- The universe is not only stranger than we imagine, it is stranger than we can imagine.
|
|
|
Apr 12 2006, 06:05 AM
Post
#4
|
|
Member Group: Members Posts: 307 Joined: 16-March 05 Member No.: 198 |
PSR 1257+12 B and C are a few times more massive than the Earth, A is about the size of the Moon. There's probably yet another body, but not even the discoverers call it a planet as it is has only one fifth the mass of Pluto. Interesting. Yet again it seems to be only the term "planet" which attracts this debate. Consider neutron stars. They are not even as big as many asteroids or Kuiper belt objects, much less Pluto, yet no astronomer seems to be suggesting that their diminutive size means we should stop calling them "neutron stars" and dub them (say) "neutron objects" or "neutron dwarfs" instead. ====== Stephen |
|
|
Apr 12 2006, 08:16 AM
Post
#5
|
|
Member Group: Members Posts: 249 Joined: 11-June 05 From: Finland (62°14′N 25°44′E) Member No.: 408 |
It's the mass that dominates. Even the least massive neutron stars are more massive than the Sun, and the upper limit of neutron stars is somewhere three times solar mass. So calling them "dwarfs" would be misleading despite their tiny size. But of course calling them stars is also wrong because they are not real stars anymore.
-------------------- The universe is not only stranger than we imagine, it is stranger than we can imagine.
|
|
|
Lo-Fi Version | Time is now: 31st October 2024 - 11:48 PM |
RULES AND GUIDELINES Please read the Forum Rules and Guidelines before posting. IMAGE COPYRIGHT |
OPINIONS AND MODERATION Opinions expressed on UnmannedSpaceflight.com are those of the individual posters and do not necessarily reflect the opinions of UnmannedSpaceflight.com or The Planetary Society. The all-volunteer UnmannedSpaceflight.com moderation team is wholly independent of The Planetary Society. The Planetary Society has no influence over decisions made by the UnmannedSpaceflight.com moderators. |
SUPPORT THE FORUM Unmannedspaceflight.com is funded by the Planetary Society. Please consider supporting our work and many other projects by donating to the Society or becoming a member. |