Basic object information

Name: M 51
Popular name: Whirlpool Galaxy
Type of object: Galaxy
Magnitude: 8.9
Surface brightness: 12.5 mag/sq arcmin
Size: 10.8'x6.6'
Position angle: 163°

Position (epoch of date)

Right ascension: 13h 29m 59s
Declination: +47° 10' 35"
Constellation: Canes Venatici

Local information

Altitude:  16° 51' 44"
Azimuth: 40° 57' 10"

Rise: 20h 32m 11s  
Transit: 7h 39m 16s
Set: 18h 42m 26s  

Star atlas chart numbers:

Herald-Bobroff Astroatlas, Chart C-29
Millennium Star Atlas, Charts 589-590 (Vol II)
Sky Atlas 2000.0, Chart 7
Uranometria 2000 Chart 76, Vol 1


Revised NGC/IC Catalog Data

Wolfgang Steinicke, Feb 2001

Names and designations

M 51
PGC 47404
NGC 5194
UGC 8493
MCG 8-25-12
IRAS13277+4727
KCPG 379A
ZWG 246.8

Type of object: Galaxy

Catalog position for epoch J2000.0

Right ascension:	13h 29m 52.6s
Declination:		+47° 11' 42"


Object information

Magnitude: 8.9
Size: 10.8'x6.6'
Position angle: 163°

Object classification: Sbc     
Remarks: Whirlpool galaxy

Saguaro Astronomy Club v7.2 Catalog Data

Saguaro Astronomy Club, August 2000

Names and designations

M 51
NGC 5194

Type of object: Galaxy

Catalog position for epoch J2000.0

Right ascension:	13h 29m 53.3s
Declination:		+47° 11' 48"

Constellation: Canes Venatici

Object information

Magnitude: 8.4
Size: 10.8'x6.6'
Position angle: 163°

Object classification: Sbc
Description: !!!,Great spiral nebula
Notes: Whirlpool Gal;interacting pair;classic spiral

LEDA Catalog Data

Lyon-Meudon Extragalactic Database (LEDA) supplied by the LEDA team at the CRAL-Observatoire de Lyon (France)

Names and designations

PGC 47404
MESS 51
NGC 5194
UGC 8493
MCG 8-25- 12
CGCG 246- 8
IRAS13277+4727
(ARP 85 )
KCPG 379A
(VV 1 )
VV 403

Position information

Right ascension (J2000.0):	13h 29m 53.3s
Declination (J2000.0):		+47° 11' 48"
(Coordinates have high accuracy)

Galactic longitude:	104.85°
Galactic latitude:	68.56°

Supergalactic longitude:	70.95°
Supergalactic latitude:	17.33°

Size and shape information

Apparent major isophotal diameter (D25): 9.9'
Mean error in log10 diameter: 0.095
Ratio of major to minor axes (R25): 1.44
Mean error in log10 R25: 0.101
Major axis position angle: 163°
Inclination between line of sight and polar axis: 47.542°
Apparent corrected diameter: 10.3'
Lyon galaxy group membership number: 347

Morphological information

Morphological type: Sbc   
Object is multiple
Morphological type code: 4.032
Error in morphological type code: 0.349
Luminosity class code: 1.043
Error in luminosity class code: 0.226

Magnitude and colour index information

Total B magnitude: 8.943
Error in B magnitude: 0.168
Mean surface brightness: 21.368 mag/sq arcsec
Error in surface brightness: 0.490 mag/sq arcsec
Total B-V colour index: 0.600
Effective U-B colour index: -0.010
Effective B-V colour index: 0.680
21cm line width at 20% of peak (w20): 199.886 km/sec
Error in w20: 12.342 km/sec
21cm line width at 50% of peak (w50): 145.500 km/sec
Error in w50: 19.326 km/sec
Central velocity dispersion: 100 km/sec
Error in log10 velocity dispersion: 0.097
21cm line flux in magnitude: 11.624
Error in 21cm line flux in magnitude: 0.255
Far infrared magnitude: 7.857
Galactic extinction in B mag: 0.261 mag
Extinction in B mag due to inclination: 0.256 mag
21cm self-absorption in magnitude: 0.022 mag
Luminosity index: 0.516
Total apparent corrected B mag: 8.422
Mean surface brightness within isophote 25: 22.367 mag/sq arcsec
Maximum rotational velocity: 97.3 km/sec
Error in log10 rotational velocity: 0.103
Corrected 21cm line flux in magnitude: 11.602
21cm index bt-am21c in magnitude. 3.180

Radial velocity information

Heliocentric RV from radio measurements: 461.0 km/sec
Error in radio measurements: 13.1 km/sec
Heliocentric RV from optical measurements: 462.1 km/sec
Error in optical measurements: 29.4 km/sec
Mean heliocentric RV: 461.2 km/sec
Error in mean measurements: 12.0 km/sec
RV with respect to local group: 537.9 km/sec
RV with respect to GSR: 548.8 km/sec
RV corrected for infall of LG onto Virgo: 672.1 km/sec
RV with respect to the 3K CMB: 638.0 km/sec
Kinematic distance modulus: 29.762
Absolute B magnitude: -19.825