M91
NGC 4548
천체 데이터
- 카탈로그 지정명
- M91
- 유형
- Galaxy
- 별자리
- Coma Berenices
- 등급
- 10.2
- 적경
- 12h 35m 26.4s
- 적위
- +14° 29' 47.0"
- 거리
- 63,000,000 광년
- 각크기
- 5.4
서베이 이미지
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M91 소개
설명
M91 is a barred spiral galaxy in Coma Berenices, about 63 million light-years from Earth. It has a prominent central bar and well-defined spiral arms, making it one of the brighter barred spirals in the Virgo Cluster. The galaxy spans about 100,000 light-years. M91 was a 'lost' Messier object for nearly two centuries due to a position error.
관측 팁
Located about 1 degree south-southeast of M88 in the Virgo Cluster. In a telescope it appears as a moderately bright, oval glow with a bar-shaped central region visible in 8-inch or larger telescopes. The spiral arms are faint and require excellent conditions. It can be confused with nearby galaxies without careful chart comparison. Best observed from March through June.
역사
Cataloged by Charles Messier on March 18, 1781, but with incorrect coordinates that pointed to empty sky. M91 was 'lost' until William C. Williams identified it in 1969 as NGC 4548 by correcting Messier's position error. Some historians had previously speculated it was a comet or even a duplicate observation of M58.
재미있는 사실
M91 was the last 'lost' Messier object to be identified. Messier apparently made a reference frame error, recording the position relative to M89 instead of M58. When the correction is applied, the position matches NGC 4548 perfectly. M91 has the lowest surface brightness of any galaxy in the Messier catalog.
커뮤니티 사진 (1)
Credit: NASA, ESA, and J. Lee (California Institute of Technology). License: CC BY-SA 4.0. (Wikimedia Commons)
Skybred Feb 28, 2026