M 100
Scientific overview
M 100 is a barred spiral galaxy in the constellation Coma Berenices. It shines at apparent magnitude 9.47 and spans about 6.1 arcminutes of sky.
Observation guide
Guidance follows standard observing practice, derived from the object's real magnitude and position. A dark, moonless sky always helps.
Location in the sky
Precision measurements
Distances and velocities from SIMBAD and redshift from NED · M 100
| Distance | 4.6640e+7 ly | SIMBAD · catalogued |
| Physical size (major axis) | 82,760 ly | SIMBAD · derived |
| Physical size (minor axis) | 76,247 ly | SIMBAD · derived |
| Redshift (z) | 0.00524 ± 3.0000e-6 | NED · catalogued |
| Radial velocity | 1,566 ± 3 km/s | SIMBAD · measured |
| Right ascension (ICRS) | 185.728875 deg | SIMBAD · measured |
| Declination (ICRS) | 15.822305 deg | SIMBAD · measured |
Full field-level provenance
- Distance: Centre de données astronomiques de Strasbourg (CDS) · SIMBAD · mesDistance · dist · 2018ApJ...861...49H · distance indicator: kin · catalogued value · source value 14.3 Mpc · retrieved 2026-07-11
- Physical size (major axis): Centre de données astronomiques de Strasbourg (CDS) · derived (OpenNGC angular size × SIMBAD distance) · physical size = angular size × distance (small-angle); angular size from OpenNGC, distance from SIMBAD mesDistance · derived · retrieved 2026-07-11
- Physical size (minor axis): Centre de données astronomiques de Strasbourg (CDS) · derived (OpenNGC angular size × SIMBAD distance) · physical size = angular size × distance (small-angle); angular size from OpenNGC, distance from SIMBAD mesDistance · derived · retrieved 2026-07-11
- Redshift (z): NASA/IPAC Extragalactic Database · NED · ObjectLookup · Redshift · 2014MNRAS.440..696A · catalogued value · NED quality UUN · retrieved 2026-07-11
- Radial velocity: Centre de données astronomiques de Strasbourg (CDS) · SIMBAD · basic · rvz_radvel · 2022ApJS..261...21Y · direct catalogue measurement · retrieved 2026-07-11
- Right ascension (ICRS): Centre de données astronomiques de Strasbourg (CDS) · SIMBAD · basic · ra · 2020yCat.1350....0G · direct catalogue measurement · retrieved 2026-07-11
- Declination (ICRS): Centre de données astronomiques de Strasbourg (CDS) · SIMBAD · basic · dec · 2020yCat.1350....0G · direct catalogue measurement · retrieved 2026-07-11
Physical size is derived from the OpenNGC angular size and the catalogued distance (small-angle: size = angle × distance). Redshift is the object's measured redshift — a negative value is a blueshift (the galaxy is approaching, its motion dominated by local rather than cosmic expansion). Fields a source did not provide are omitted, never invented.
Other objects in Coma Berenices
| Object | Type | Mag | Size (′) |
|---|---|---|---|
| M 53M 53 · NGC 5024 | Globular cluster | 7.79 | 9 |
| Black Eye GalaxyM 64 · NGC 4826 | Barred spiral galaxy | 8.52 | 10.52 |
| M 85M 85 · NGC 4382 | Lenticular galaxy | 9.05 | 6.95 |
| NGC 4725NGC 4725 | Barred spiral galaxy | 9.38 | 9.71 |
| NGC 4494NGC 4494 | Elliptical galaxy | 9.8 | 4.35 |
| Coma PinwheelM 99 · NGC 4254 | Spiral galaxy | 9.84 | 5.04 |
| NGC 4559C 36 · NGC 4559 | Spiral galaxy | 9.92 | 10.57 |
| NGC 5053NGC 5053 | Globular cluster | 9.96 | 4.8 |
Sources
The primary and reference sources this topic draws on.
- OpenNGCOpenNGC (M. Verga) — NGC/IC, Messier, and Caldwell catalogue data
Openly-licensed deep-sky catalogue: object types, positions, magnitudes, sizes, morphology, and cross-identifiers.