Messier 91 is a barred spiral galaxy in Coma Berenices, 53 million light-years away
Messier 91 (M91, NGC 4548, Herschel 400 no. 257, PGC 041934, UGC 07753) is a barred spiral galaxy in the constellation Coma Berenices , 53 million light-years away. It shines at magnitude 11.0 and spans 5.4′ × 4.3′ of sky, about 83,100 light-years across. It is best in a small telescope, 4 to 6 inches, and it is highest in the evening sky in May.
Galaxy: a system of billions of stars, gas and dust held together by gravity, far outside the Milky Way. Spiral galaxies have a disk with arms; elliptical galaxies are smooth, round or oval swarms of older stars.
Finding Messier 91 from Vindemiatrix
Vindemiatrix
Messier 91
COMA BERENICES
Messier 91 lies 7.4° northwest of Vindemiatrix , the magnitude 2.9 star. Three fingers held at arm's length cover about 5°.
Messier 91 is highest in the evening in May
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60°N
JAN at 60°N: -1° high at 9 pm FEB at 60°N: 13° high at 9 pm MAR at 60°N: 27° high at 9 pm APR at 60°N: 39° high at 9 pm MAY at 60°N: 44° high at 9 pm JUN at 60°N: 40° high at 9 pm JUL at 60°N: 28° high at 9 pm AUG at 60°N: 13° high at 9 pm SEP at 60°N: -2° high at 9 pm OCT at 60°N: -12° high at 9 pm NOV at 60°N: -16° high at 9 pm DEC at 60°N: -12° high at 9 pm 50°N
JAN at 50°N: -6° high at 9 pm FEB at 50°N: 12° high at 9 pm MAR at 50°N: 29° high at 9 pm APR at 50°N: 47° high at 9 pm MAY at 50°N: 54° high at 9 pm JUN at 50°N: 47° high at 9 pm JUL at 50°N: 31° high at 9 pm AUG at 50°N: 11° high at 9 pm SEP at 50°N: -7° high at 9 pm OCT at 50°N: -20° high at 9 pm NOV at 50°N: -26° high at 9 pm DEC at 50°N: -20° high at 9 pm 40°N
JAN at 40°N: -12° high at 9 pm FEB at 40°N: 10° high at 9 pm MAR at 40°N: 31° high at 9 pm APR at 40°N: 53° high at 9 pm MAY at 40°N: 64° high at 9 pm JUN at 40°N: 54° high at 9 pm JUL at 40°N: 33° high at 9 pm AUG at 40°N: 10° high at 9 pm SEP at 40°N: -12° high at 9 pm OCT at 40°N: -29° high at 9 pm NOV at 40°N: -36° high at 9 pm DEC at 40°N: -29° high at 9 pm 30°N
JAN at 30°N: -17° high at 9 pm FEB at 30°N: 8° high at 9 pm MAR at 30°N: 32° high at 9 pm APR at 30°N: 58° high at 9 pm MAY at 30°N: 74° high at 9 pm JUN at 30°N: 59° high at 9 pm JUL at 30°N: 34° high at 9 pm AUG at 30°N: 7° high at 9 pm SEP at 30°N: -17° high at 9 pm OCT at 30°N: -37° high at 9 pm NOV at 30°N: -46° high at 9 pm DEC at 30°N: -37° high at 9 pm 20°N
JAN at 20°N: -21° high at 9 pm FEB at 20°N: 6° high at 9 pm MAR at 20°N: 32° high at 9 pm APR at 20°N: 60° high at 9 pm MAY at 20°N: 84° high at 9 pm JUN at 20°N: 61° high at 9 pm JUL at 20°N: 34° high at 9 pm AUG at 20°N: 5° high at 9 pm SEP at 20°N: -22° high at 9 pm OCT at 20°N: -44° high at 9 pm NOV at 20°N: -56° high at 9 pm DEC at 20°N: -45° high at 9 pm 10°N
JAN at 10°N: -25° high at 9 pm FEB at 10°N: 4° high at 9 pm MAR at 10°N: 30° high at 9 pm APR at 10°N: 60° high at 9 pm MAY at 10°N: 85° high at 9 pm JUN at 10°N: 61° high at 9 pm JUL at 10°N: 32° high at 9 pm AUG at 10°N: 3° high at 9 pm SEP at 10°N: -26° high at 9 pm OCT at 10°N: -51° high at 9 pm NOV at 10°N: -66° high at 9 pm DEC at 10°N: -52° high at 9 pm 0°
JAN at 0°: -28° high at 9 pm FEB at 0°: 1° high at 9 pm MAR at 0°: 28° high at 9 pm APR at 0°: 56° high at 9 pm MAY at 0°: 75° high at 9 pm JUN at 0°: 57° high at 9 pm JUL at 0°: 30° high at 9 pm AUG at 0°: 0° high at 9 pm SEP at 0°: -29° high at 9 pm OCT at 0°: -57° high at 9 pm NOV at 0°: -75° high at 9 pm DEC at 0°: -57° high at 9 pm 10°S
JAN at 10°S: -31° high at 9 pm FEB at 10°S: -1° high at 9 pm MAR at 10°S: 25° high at 9 pm APR at 10°S: 51° high at 9 pm MAY at 10°S: 65° high at 9 pm JUN at 10°S: 52° high at 9 pm JUL at 10°S: 26° high at 9 pm AUG at 10°S: -2° high at 9 pm SEP at 10°S: -32° high at 9 pm OCT at 10°S: -60° high at 9 pm NOV at 10°S: -85° high at 9 pm DEC at 10°S: -60° high at 9 pm 20°S
JAN at 20°S: -32° high at 9 pm FEB at 20°S: -4° high at 9 pm MAR at 20°S: 21° high at 9 pm APR at 20°S: 44° high at 9 pm MAY at 20°S: 55° high at 9 pm JUN at 20°S: 45° high at 9 pm JUL at 20°S: 22° high at 9 pm AUG at 20°S: -5° high at 9 pm SEP at 20°S: -33° high at 9 pm OCT at 20°S: -61° high at 9 pm NOV at 20°S: -84° high at 9 pm DEC at 20°S: -61° high at 9 pm 30°S
JAN at 30°S: -32° high at 9 pm FEB at 30°S: -6° high at 9 pm MAR at 30°S: 16° high at 9 pm APR at 30°S: 37° high at 9 pm MAY at 30°S: 45° high at 9 pm JUN at 30°S: 37° high at 9 pm JUL at 30°S: 18° high at 9 pm AUG at 30°S: -7° high at 9 pm SEP at 30°S: -33° high at 9 pm OCT at 30°S: -58° high at 9 pm NOV at 30°S: -74° high at 9 pm DEC at 30°S: -58° high at 9 pm 40°S
JAN at 40°S: -32° high at 9 pm FEB at 40°S: -8° high at 9 pm MAR at 40°S: 11° high at 9 pm APR at 40°S: 29° high at 9 pm MAY at 40°S: 35° high at 9 pm JUN at 40°S: 29° high at 9 pm JUL at 40°S: 13° high at 9 pm AUG at 40°S: -9° high at 9 pm SEP at 40°S: -32° high at 9 pm OCT at 40°S: -53° high at 9 pm NOV at 40°S: -64° high at 9 pm DEC at 40°S: -53° high at 9 pm
below horizon
low
20-40°
40-60°
overhead-ish
The chart gives its height above the horizon at 9 pm through the year, from 60°N to 40°S. It can be seen from the whole northern hemisphere and south to about 76°S, and never sets north of 76°N.
Messier 91 is 53 million light-years away
The light seen from Messier 91 tonight left it about 53 million years ago, long before modern humans existed. It ranks 98 of 109 by distance among the 110 Messier objects. Distance source: Cepheids, Anand 2021.
Objects within 6° of Messier 91
M88, spiral galaxy, 50′ M90, spiral galaxy, 1.4° NGC 4477, galaxy, 1.6° NGC 4459, galaxy, 1.6° NGC 4473, galaxy, 1.7° M89, elliptical galaxy, 1.9° NGC 4419, galaxy, 2.1° NGC 4550, galaxy, 2.3°
Messier 91 catalog data
Field Value
Designations M91, NGC 4548, Herschel 400 no. 257, PGC 041934, UGC 07753 Type barred spiral galaxy Constellation Coma Berenices Right ascension (J2000) 12h 35.4m Declination (J2000) +14° 30′ Magnitude 11.0 Surface brightness 23.2 mag/arcmin² Apparent size 5.4′ × 4.3′ True size 83,100 light-years Distance 53 million light-years (Cepheids, Anand 2021) Best month May Best with Small telescope Messier marathon order 59 Herschel 400 number 257
