| 查看: 1599 | 回复: 8 | |||
| 当前只显示满足指定条件的回帖，点击这里查看本话题的所有回帖 | |||
[交流]
Everyday News-Diamond Planet Orbits a Pulsar
|
|||
Astronomers have discovered the densest extrasolar planet yet: A Jupiter-mass remnant of a carbon- and oxygen-rich star that measures no more than 55,000 kilometers across. The odd world, whose density is on average at least 23 grams per cubic centimeter (or about twice that of lead), is probably crystalline and possibly largely composed of ultradense diamond. The planet orbits its parent sun—a pulsar, or a rapidly-spinning neutron star that emits an intense beam of radio waves, dubbed PSR J1719-1438—once every 2 hours and 10 minutes, the researchers report online today in Science. The planet’s orbit measures about 600,000 kilometers across, only 50% more than the average distance from Earth to the moon. How such a dense planet formed is unclear, the researchers say, but it’s probably the crystalline vestige of a white dwarf star whose atmosphere was stripped away by the parent pulsar. Most of the pulsars that spin faster than once per 20 milliseconds are part of a binary star system, but about 30% have no companions whatsoever, the scientists note. Only one other rapidly-spinning pulsar is known to be orbited by Earth-mass planets—a sign that exotic planets such as this megadiamond are, like their Earthly counterparts, rare indeed. |
回复此楼» 猜你喜欢
本人女孩
已经有9人回复
-
085501机械专硕 302分 不挑专业求调剂
已经有7人回复
-
一志愿厦大0856，306求调剂
已经有5人回复
-
366求调剂
已经有3人回复
-
一志愿新疆大学085401，314分
已经有3人回复
-
271求调剂
已经有14人回复
-
305求调剂
已经有4人回复
-
211本科材料化工求调剂
已经有7人回复
-
332求调剂
已经有13人回复
-
295求调剂
已经有4人回复
4楼2011-09-06 19:10:20
WG222
木虫 (正式写手)
- 应助: 18 (小学生)
- 贵宾: 0.02
- 金币: 2155.4
- 红花: 4
- 沙发: 4
- 帖子: 379
- 在线: 169.8小时
- 虫号: 454642
- 注册: 2007-11-10
- 性别: GG
- 专业: 污染控制化学
2楼2011-09-06 18:50:48
★
小木虫(金币+0.2):抢了个小板凳，给个红包
小木虫(金币+0.2):抢了个小板凳，给个红包
  |
3楼2011-09-06 18:53:33
7楼2011-09-07 00:37:23
