Spiral Galaxy · Ursa Major

M101 Pinwheel Galaxy

Magnitude
7.9
Season
Spring
Difficulty
Very Hard
Star-hop chart
M1010.0° field0° rotation
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Imaging reference
Pinwheel Galaxy (M101) Spiral Galaxy

Observer's guide

About Pinwheel Galaxy

Pinwheel Galaxy (M101) is catalogued as a spiral galaxy in Ursa Major. Its J2000 position is RA 14:03:12.54, Dec +54:20:56.2, corresponding to 210.8024 degrees RA and 54.3488 degrees Dec. The local catalogue places it about 27,000,000 light-years away. Its referenced angular extent is approximately 21.88 by 20.89 arcminutes.

Observing tips

StarWatchr rates this as a very hard target at magnitude 7.9. It is associated with spring observing, with midnight placement typically strongest around April. From 52 degrees north its theoretical meridian altitude is about 87.7 degrees; local horizons and the live altitude chart determine the practical window.

A small telescope under reasonably dark skies is a good starting point; use the live altitude chart to choose its highest point.

What to expect

The SIMBAD classification for the matched source is GiP. SIMBAD records the morphology as S_AB. A published radial velocity value is 243 km/s. The SIMBAD record currently connects it to 3160 bibliographic references.

Its roughly 21.9 arcminute span suits a medium field of view. Use the listed 21.88 by 20.89 arcminute extent to check framing, and treat catalogue magnitude as integrated brightness rather than a direct measure of visual contrast.

Sourced catalogue data

Scientific record

Measurements for M101 are kept separate from practical observing guidance.

Coordinates (J2000/ICRS)
RA 210.802429° · Dec 54.34875°
SIMBAD classification
GiP
Morphology
S_AB
Angular extent
21.88′ × 20.89′
Surface brightness
23.18 mag/arcsec²
Radial velocity
243.03 km/s
Redshift
0.000811
Linked bibliography
3,160 references
Best midnight placement
April
Observable latitude range
-35.7° to 90°

Source: SIMBAD astronomical database (CDS, Strasbourg) (ODbL; checked 2026-08-09). Catalogue values may change when new measurements are published.

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