NGC 2964
Intermediate spiral galaxy in Leo with a weak bar and four spiral arms.
NGC 2964 is an intermediate spiral galaxy located in the constellation of Leo. It lies at a distance of about 60 million light years from Earth and spans roughly 60,000 light years across. Discovered by William Herschel on December 7, 1785, it is the brightest member of the NGC 2964 group.
Quick Facts
- Epoch
- J2000
- Ra
- 09 · 42 · 54.2
- Dec
- 31 · 50 · 51
- Dist Ly
- 18.7 ±
- Z
- 0.0044300.000040
- Appmag V
- 11.2
- Constellation Name
- Leo
Facts from the source article.
Lore & Background
NGC 2964 shows evidence of a weak bar running across the galaxy's minor axis. It has four spiral arms: two emerge from ansae at each end of the bar, and two emerge near the center of the bar; the arms from the bar ends have higher surface brightness. All arms except the west arm have a knotty appearance. The outer parts exhibit twisted stellar kinematics, but the rotation is otherwise regular.
Spiral dust lanes run toward the center, where star formation may occur. A circumnuclear ring observed in [OIII]/H-beta could be a site of active star formation, and double-peaked carbon monoxide emission lines also suggest a nuclear star-forming ring. The central region hosts a young-intermediate age stellar population, likely from constant starburst activity lasting about 5 billion years. The total star formation rate is estimated at about 4 solar masses per year.
The nucleus appears to feature HII region activity. Spectrographic study reveals double-peaked emission lines, possibly from an ionization cone created by an active galactic nucleus. At the center lies a supermassive black hole with an upper mass limit between 1.4 and 24 million solar masses.
Reader's Guide
NGC 2964 is significant as the brightest galaxy in its namesake group, which includes NGC 2968, NGC 2970, NGC 3003, NGC 3011, and NGC 3021. It forms a non-interacting pair with NGC 2968, separated by 5.8 arcminutes, yet a hydrogen bridge connects the two galaxies, and a tail extends toward NGC 2970. Other nearby galaxies include NGC 3118, NGC 3067, NGC 3032, and NGC 3026, along with their respective groups.
The galaxy's legacy lies in its complex structure: a weak bar, four spiral arms with differing surface brightness, and a knotty appearance in most arms. The central region's ongoing star formation, possibly fueled by a circumnuclear ring and dust lanes, combined with evidence of an active galactic nucleus and a supermassive black hole, make NGC 2964 a valuable object for studying galaxy evolution, bar dynamics, and nuclear activity. Its non-interacting yet connected pair with NGC 2968 also offers insight into galaxy interactions without direct collision.
Did You Know?
- NGC 2964 has four spiral arms, two emerging from ansae at each end of the bar and two near the bar's center.
- A hydrogen bridge connects NGC 2964 to NGC 2968, though they form a non-interacting pair.
- The galaxy's central supermassive black hole has an upper mass limit between 1.4 and 24 million solar masses.
- The total star formation rate of NGC 2964 is estimated at about 4 solar masses per year.
Frequently Asked Questions
What is NGC 2964?
NGC 2964 is an intermediate spiral galaxy roughly 60 million light years from Earth, spanning about 60,000 light years in diameter. It features a faint central bar with four spiral arms winding outward from it.
In which constellation can you find NGC 2964?
This galaxy sits in the constellation Leo, making it accessible during northern-sky summer viewing. It is also the brightest member of the small NGC 2964 group of galaxies.
Who first observed NGC 2964 and when?
William Herschel recorded the galaxy on December 7, 1785, as part of his sweeping surveys of faint deep-sky objects. His observations later fed into the New General Catalogue of nebulae and clusters.
What structural features distinguish NGC 2964?
It shows a weak bar at its core from which four spiral arms extend, placing it between tightly wound barred spirals and loosely wound unbarred types. That intermediate classification gives it a moderately wound, open appearance.
Why do astronomers and stargazers consider NGC 2964 noteworthy?
As the brightest galaxy in its small group, it serves as a handy reference point for studying that cluster's dynamics. Its relatively clear arm structure also makes it a rewarding target for amateur observers with moderate-aperture telescopes.
More in NGC Objects, Part 5 1-24
Spotted an error? Know more?
Reader corrections go straight into our review queue. Suggest an edit · How this site is sourced