Galaxies Messier 99, NGC 4298, NGC 4302

M 98 + M 99
M 98 + M 99: Galaxies M 99 (left) and M 98 (right) in Coma Berenices; TS Triplet APO 90, Reducer Photoline 0.79 (f=490mm / f5.44), SBIG ST-8300; 14L x 900sec 1×1; Bernese Highlands; © 2020 Bernhard Blank, Dragan Mihajlovic

History

The galaxy M 99 was discovered by Pierre Méchain on March 15, 1781 and cataloged by Charles Messier on April 13. He wrote: «Nebula without a star, of very weak light, but somewhat clearer than the previous one [M 98], above the northern wing of the Virgin and next to the same star No. 6 of Berenice's hair. The nebula lies between two stars of seventh and eighth magnitude. M. Méchain sighted them on March 15, 1781.» [281]

Physical Properties

M 99
M 99: Image taken with the Hubble Space Telescope [215]

M 99 is a spiral galaxy of the morphological type SA(s)c and the brightness class LC III. It is moving away from us at about 2400 km/s and the distance is about 15 Mpc (49 million light years). [194] It has a somewhat asymmetrical appearance with one normal-looking arm and one elongated, less twisted arm. The reason for this could have been a close and rapid encounter with the galaxy NGC 4262 about 280 million years ago. The distance from M 99 to the center of the Virgo cluster (M 87) is about 1 Mpc. [293]

«Catalogue of Principal Galaxies (PGC)», Paturel et al. 1989 [144]
DesignationsPGC 39578: NGC 4254, UGC 7345, MCG 3-31-99, M 99, CGCG 99-11, CGCG 98-144, VCC 307, IRAS 12162+1441
Right Ascension (J2000.0)12h 18m 49.3s
Declination (J2000.0)+14° 25' 07"
Morphological TypeS
Dimensions5.3' x 4.6'
Visual Magnitude10.4 mag
Radial Velocity (HRV)2407 km/s
Position Angle°

Further Galaxies in that Area

The small galaxy NGC 4262 was discovered by William Herschel on April 8, 1784. A morphological type of SB_a can be found here at Simbad. Measured values from the last 20 years show speeds of 1359 km/s to 1367 km/s and distances of 15.4 Mpc to 19.5. She is member No. VCC 355 of the Virgo Cluster. [145, 196]

The galaxy IC 781 is even more inconspicuous. It was discovered on May 10, 1888 by Guillaume Bigourdan. Morphological type dS0, heliocentric speed 1356 km/s and distance 14 Mpc. Virgo Cluster member number VCC 389. [145, 196]

NGC 4298, NGC 4302
NGC 4298, NGC 4302: NGC 4298 (right) and NGC 4302 (left): Image taken with the Hubble Space Telescope [294]

The beautiful galaxy pair NGC 4298 and NGC 4302 was discovered by William Herschel on April 8, 1784. Although they look very different because we look at them from different angles, they are quite similar in structure. Although both galaxies are right next to each other from our perspective, they are far enough apart that no gravitational interaction can be observed between them.

NGC 4298 is of morphological type SA(rs)c and about 16 Mpc (52 million light years) away. We see them at an angle of about 70°. Their size is estimated to be around 45'000 light years, roughly a third of our Milky Way. With 17 billion solar masses, it is less than two percent as heavy as our Milky Way.

Of NGC 4302, which we see directly from the edge, only the central dust band is visible. It is about 20 Mpc (65 million light years) away. A large blue area in the southern area is evidence of recent star formation. Its diameter is estimated to be around 87'000 light years, which is around 60% of that of our Milky Way. It contains about 110 billion solar masses, about a tenth of our Milky Way. [194, 196, 294]

«Catalogue of Principal Galaxies (PGC)», Paturel et al. 1989 [144]
NameRA [hms]Dec [dms]mTypeDim [']Btot [mag]HRV [km/s]PA [°]
NGC 426212 19 30.6+14 52 44LB1.8 x 1.612.51360
IC 78112 20 02.8+14 57 39L1.1 x .914.5
NGC 429812 21 32.6+14 36 25S3.2 x 1.912.11140140
NGC 430212 21 42.4+14 36 05S5.3 x 1.012.61108178

Finder Chart

The galaxies are located in the constellation Coma Berenices between the stars Vindemiatrix (ε Virginis) and Denebola (β Leonis). The best time for observation is January to July.

Chart M 99
Chart created using SkySafari 6 Pro and STScI Digitized Sky Survey. [149, 160]

References

144Catalogue of Principal Galaxies (PGC); Paturel G., Fouque P., Bottinelli L., Gouguenheim L.; Astron. Astrophys. Suppl. Ser. 80, 299 (1989); cdsarc.unistra.fr/viz-bin/cat/VII/119 (2021-02-18)
145SIMBAD astronomical database; simbad.u-strasbg.fr/simbad
149SkySafari 6 Pro, Simulation Curriculum; skysafariastronomy.com
160The STScI Digitized Sky Survey; archive.stsci.edu/cgi-bin/dss_form
194NASA/IPAC Extragalactic Database (NED); ned.ipac.caltech.edu (2020-12-27)
196Celestial Atlas by Curtney Seligman; cseligman.com/text/atlas.htm (2020-12-28)
215Explore - The Night Sky | Hubble’s Messier Catalog; nasa.gov/content/goddard/hubble-s-messier-catalog (2020-12-31)
281«Catalogue Nébuleuses et des Amas D'Étoiles» Observées à Paris, par M. Messier, à l'Observatoire de la Marine, hôtel de Clugni, rue des Mathurins. «Connoissance des temps ou connoissance des mouvements célestes, pour l'année bissextile 1784 » Page 227; gallica.bnf.fr/ark:/12148/bpt6k6514280n/f235 (2021-02-21)
293«NGC 4254: a spiral galaxy entering the Virgo cluster»; B. Vollmer, W. Huchtmeier, W. van Driel; A&A Volume 439, Number 3, September I 2005; DOI:10.1051/0004-6361:20041350
294Spiral Galaxy Pair NGC 4302 and NGC 4298; hubblesite.org/image/4019/gallery (2021-03-10)