http://chineseinput.net/에서 pinyin(병음)방식으로 중국어를 변환할 수 있습니다.
변환된 중국어를 복사하여 사용하시면 됩니다.
- 中文 을 입력하시려면 zhongwen을 입력하시고 space를누르시면됩니다.
- 北京 을 입력하시려면 beijing을 입력하시고 space를 누르시면 됩니다.
RISS 인기검색어
- 검색키워드
- 저자 : Weryk, Robert (검색결과 1 건)
- 무료
- 기관 내 무료
- 유료
-
FRAGMENTATION KINEMATICS IN COMET 332P/IKEYA-MURAKAMI
Jewitt, David,Mutchler, Max,Weaver, Harold,Hui, Man-To,Agarwal, Jessica,Ishiguro, Masateru,Kleyna, Jan,Li, Jing,Meech, Karen,Micheli, Marco,Wainscoat, Richard,Weryk, Robert American Astronomical Society 2016 ASTROPHYSICAL JOURNAL LETTERS - Vol.829 No.1
<P>We present initial time-resolved observations of the split comet 332P/Ikeya-Murakami taken using the Hubble Space Telescope. Our images reveal a dust-bathed cluster of fragments receding from their parent nucleus at projected speeds in the range 0.06-3.5 m s(-1) from which we estimate ejection times from 2015 October to December. The number of fragments with effective radii greater than or similar to 20 m follows a differential power law with index gamma = -3.6 +/- 0.6, while smaller fragments are less abundant than expected from an extrapolation of this power law. We argue that, in addition to losses due to observational selection, torques from anisotropic outgassing are capable of destroying the small fragments by driving them quickly to rotational instability. Specifically, the spin-up times of fragments. 20 m in radius are shorter than the time elapsed since ejection from the parent nucleus. The effective radius of the parent nucleus is re <= 275 m (geometric albedo 0.04 assumed). This is about seven times smaller than previous estimates and results in a nucleus mass at least 300 times smaller than previously thought. The mass in solid pieces, 2 x 10(9) kg, is about 4% of the mass of the parent nucleus. As a result of its small size, the parent nucleus also has a short spin-up time. Brightness variations in time-resolved nucleus photometry are consistent with rotational instability playing a role in the release of fragments.</P>
연관 검색어 추천
이 검색어로 많이 본 자료
활용도 높은 자료
