Picture of the Day · NASA
NGC 3660 and Burçin's Galaxy
2026-05-26
The upper galaxy might be more photogenic, but the lower galaxy is more unusual. The galaxy up top is NGC 3660, a spiral galaxy similar to our own Milky Way galaxy in that it has several bright blue spiral arms and a central bar of stars, dust, and gas. Captured by chance in the featured deep and colorful image, surprisingly, is SN 2026cff, a supernova found just to the right of the central bar. Farther in the distance is the bottom galaxy, known informally as Burçin’s galaxy, but formally cataloged as LEDA 1000714. The center of this galaxy appears to be an old elliptical galaxy, but it is strangely surrounded by not one but two rings of stars. What created Burçin's galaxy is a mystery and remains a continuing topic of research, but it likely involves the accretion of one or more smaller galaxies.
via NASA APOD
Key facts
- Discovered by
- Friedrich Tietjen
- Discovery date
- January 4, 1866
- Pronunciation
- / ˈ s ɛ m ɪ l ə /
- Named after
- Semele
- Minor planet category
- Main belt
- Adjectives
- Semelean / s ɛ m ɪ ˈ l eɪ ə n /
- Aphelion
- 562.652 million km (3.761 AU)
- Perihelion
- 369.116 million km (2.467 AU)
- Semi major axis
- 465.884 million km (3.114 AU )
- Orbital period sidereal
- 2,007.366 d (5.50 a )
- Average orbital speed
- 16.69 km/s
- Mean anomaly
- 264.875°
- Inclination
Article
86 Semele is a large and very dark main-belt asteroid with an orbital period of 5.5 years. It is rotating with a period of 16.6 hours, and varies in magnitude by 0.13 during each cycle. This object is classified as a C-type asteroid and is probably composed of carbonates.
Semele was discovered by German astronomer Friedrich Tietjen on January 4, 1866. It was his first and only asteroid discovery. It is named after Semele, the mother of Dionysus in Greek mythology.