Spiral Galaxy · Coma Berenices

M99 NGC 4254

Magnitude
9.9
Season
Spring
Difficulty
Hard
Star-hop chart
M990.0° field0° rotation
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Imaging reference
NGC 4254 (M99) Spiral Galaxy

Observer's guide

About NGC 4254

NGC 4254 (M99) is catalogued as a spiral galaxy in Coma Berenices. Its J2000 position is RA 12:18:49.60, Dec +14:24:59.4, corresponding to 184.7068 degrees RA and 14.4165 degrees Dec. The local catalogue places it about 60,000,000 light-years away. Its referenced angular extent is approximately 4.6 by 4.28 arcminutes.

Observing tips

StarWatchr rates this as a hard target at magnitude 9.9. It is associated with spring observing, with midnight placement typically strongest around March. From 52 degrees north its theoretical meridian altitude is about 52.4 degrees; local horizons and the live altitude chart determine the practical window.

Because it is faint, use a larger aperture where possible, avoid bright Moon conditions, and use averted vision.

What to expect

The SIMBAD classification for the matched source is H2G. SIMBAD records the morphology as SA. A published radial velocity value is 2418 km/s. The SIMBAD record currently connects it to 1019 bibliographic references.

At roughly 4.6 arcminutes across, it benefits from a narrower field and adequate image scale. Use the listed 4.6 by 4.28 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 M99 are kept separate from practical observing guidance.

Coordinates (J2000/ICRS)
RA 184.706771° · Dec 14.416489°
SIMBAD classification
H2G
Morphology
SA
Angular extent
4.6′ × 4.28′
Position angle
63°
Surface brightness
21.76 mag/arcsec²
Radial velocity
2,418 km/s
Redshift
0.00809837
Linked bibliography
1,019 references
Best midnight placement
March
Observable latitude range
-75.6° 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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