Messier 63: The Sunflower Galaxy
- Catalog
- M63 · NGC 5055
- Type
- Spiral galaxy
- Constellation
- Canes Venatici
- Best season
- Spring evenings
- Magnitude
- 8.6
- Apparent size
- 10′ × 6′
- Distance
- 27,000,000 light-years
- Position (J2000)
- 13h 15.8m, +42° 02′
- Best seen with
- Small telescope
- Discovered
- Pierre Méchain, 1779
The Sunflower Galaxy is a bright spiral in Canes Venatici, below the handle of the Big Dipper. Its name comes from its patchy, petal-like spiral arms in photos. In a telescope it is an easy, bright oval, though the arms need dark skies and a larger instrument.
What it is
M63 is a spiral galaxy about 27 million light-years away. Its 10-arcminute length works out to roughly 78,000 light-years. It is a flocculent spiral: instead of two long, clean arms like its neighbor the Whirlpool (M51), it has many short, broken arm segments dotted with star-forming regions. M63 belongs to the same small group of galaxies as M51. A supernova, 1971I, was seen in it in 1971.
When to see it
M63 is a spring object. It is highest around midnight in mid-April and well placed in the evening from April through June. From about 40°N it passes nearly overhead, at about 88°. From the Southern Hemisphere it stays low in the north and is hard to see from far southern latitudes.
How to find it
Draw a line from Cor Caroli (Alpha Canum Venaticorum) to Alkaid, the end star of the Big Dipper's handle. M63 lies near this line about a third of the way along, about 5° northeast of Cor Caroli. The 5th-magnitude star 20 Canum Venaticorum is a closer guide: M63 is about 1½° north-northwest of it. From M63, M51 is about 6° to the north-northeast.
What you will see
Binoculars under dark skies show M63 as a small, faint oval glow. A small telescope shows a bright, elongated oval with a bright, almost star-like core. A 200 mm telescope on a dark night shows the outer halo as grainy and uneven, a hint of the patchy arms, and the oval grows larger with averted vision. From suburban skies the core and inner oval remain visible, but the faint outer parts fade away.
History
M63 was the first deep-sky discovery of Pierre Méchain, Charles Messier's friend and colleague, who found it on June 14, 1779. Messier observed it and added it to his catalog the same day. Lord Rosse later listed M63 among the spiral nebulae he had recognized by 1850.