Messier 86 (M 86) is a lenticular or elliptical galaxy located in the constellation Virgo. It is a prominent member of the Virgo Cluster of galaxies.
Discovery and Designation
- Discovered by Charles Messier on March 18 1781, it was added to his catalogue as the 86th entry.
- Alternative catalogue designations include NGC 4406, PGC 40639, and UGC 7536.
Location and Distance
- Right ascension (J2000): 12h 26m 11.7s
- Declination (J2000): +12° 56′ 46″
- Estimated distance from the Milky Way: approximately 52 million light‑years (≈16 Mpc), based on surface‑brightness fluctuation and Cepheid‑independent methods.
Physical Characteristics
- Morphological type: S0(1) or E3 (lenticular/elliptical)
- Apparent visual magnitude: 8.9 mag (visible with small telescopes)
- Absolute magnitude: −21.9 mag, indicating a luminosity comparable to that of the Milky Way.
- Major axis diameter: roughly 5.2 arcminutes, corresponding to a physical size of about 77 kly.
- Stellar mass: on the order of 10¹¹ M☉.
Kinematics
- Radial velocity relative to the Sun: –244 km s⁻¹, implying it is moving toward the Milky Way at a modest speed, a notable exception among Virgo Cluster members which generally exhibit recession velocities.
- Internal stellar velocity dispersion is high, typical for massive early‑type galaxies.
Interstellar Medium and Activity
- X‑ray observations reveal a hot gaseous halo extending several kiloparsecs, with temperatures around 0.7 keV.
- The galaxy shows evidence of ram‑pressure stripping, likely due to its rapid motion through the intracluster medium of Virgo.
- A low‑luminosity active galactic nucleus (AGN) has been detected in radio and X‑ray bands, suggesting a central supermassive black hole of mass ≈ 1–2 × 10⁸ M☉.
Nearby Objects and Environment
- Lies within 0.5 degrees of the bright Virgo Cluster core galaxy M 87.
- Several dwarf satellite galaxies have been identified in its vicinity, though the dense cluster environment makes definitive association challenging.
Observational Notes
- Visible to the naked eye under exceptional dark‑sky conditions; easily observed with binoculars and modest telescopes.
- In long‑exposure astrophotography, its bright core and extended halo are prominent, especially in red‑filtered images that accentuate the ionized gas.
References
- Messier Catalogue, Charles Messier (1781).
- de Vaucouleurs, G., de Vaucouleurs, A., Corwin, H. G., et al. “Third Reference Catalogue of Bright Galaxies.” (RC3, 1991).
- NASA/IPAC Extragalactic Database (NED) – entry for NGC 4406.
- Böhringer, H. et al. “X‑ray observations of the Virgo Cluster.” Astron. Astrophys., 1994.
All data presented are derived from established astronomical surveys and peer‑reviewed literature.
