M82
Key Astrophysical Data
Catalog Designations
M82, NGC 3034, Cigar Galaxy
Position in the Sky
Ursa Major (RA 09h 55.8m / Dec +69° 40′)
Apparent Size
11.2′ × 4.3′ (Distinctly elongated shape)
Apparent Magnitude
8.41 mag (Well visible in small telescopes)
Discovery Date
December 31, 1774 (by Johann Elert Bode)
Object Type
Starburst Galaxy (Originally Spiral, now I0 / Irregular)
Estimated Stars
~30 Billion Stars
Mass (vs Milky Way)
~5 × 10¹⁰ M☉ (Roughly 5% of our galaxy's mass)
Distance from Earth
~12 Million Light Years
Physical Size
~37,000 Light Years across
Object Overview & Facts
Discovered in the Shadow of a Giant: M82 was first discovered by German astronomer Johann Elert Bode on New Year's Eve in 1774, alongside the brighter M81. Charles Messier added it to his catalog on February 9, 1781, based on an independent observation by Pierre Méchain. Visually, it appears as a narrow, elongated smudge, earning it the popular nickname the "Cigar Galaxy."
Galactic Collision & Starburst: In astronomical terms, M82 recently—about 300 million years ago—experienced a very close flyby with the massive M81 galaxy. The strong gravitational tides from M81 ripped apart M82's original spiral arms and funneled a tremendous amount of hydrogen gas straight into its core. This shock triggered a "starburst." Stars are being born in M82's center up to ten times faster than in our entire Milky Way.
The Galactic Superwind: As a result of this frantic star formation, massive, hot stars are born, quickly burn through their fuel, and explode as supernovae. The combined pressure from the stellar winds of young stars and hundreds of exploding supernovae creates a massive "superwind." This wind drives giant plumes of ionized hydrogen (visible in deep red on images) outward at millions of kilometers per hour, perpendicular to the galactic disk. These jets extend up to 10,000 light-years into deep space.
The Famous Supernova SN 2014J: In late January 2014, Supernova 2014J flared up in M82, discovered by astronomer Stephen Fossey and his students at University College London. It was a Type Ia supernova (a thermonuclear explosion of a white dwarf) and became the second-closest supernova to Earth in 25 years. Peaking at a magnitude of 10.5, this "standard candle" critically helped scientists measure the universe's expansion rate and study the interstellar dust within M82.
Narrowband Imaging Target: M82 presents a unique challenge for astrophotographers. In standard broadband (RGB) imaging, the galaxy looks merely like a mottled, yellowish cigar bisected by dark dust lanes. The real magic happens when using an H-alpha filter. The extremely narrow passband (transmitting only 656 nm photons) reveals the dramatic, chaotic eruptions of material blasting from the core, giving the galaxy its signature "exploding" look.
Deep Sky Objects Size Comparison Laboratory
Interactive Scaling Explanation: This panel acts as a dynamic comparator of angular sizes in the night sky. All selected objects are rendered exactly over each other from a common center, allowing an immediate, direct comparison. The Full Moon (diameter 31') serves as a permanent baseline reference. You can clearly see how tiny M82 is even compared to its giant neighbor M81.
Cosmic Time Machine: M82 vs. Earth's History
The Photon Arrives: Right now, the light captured in this photograph is ending its ~12-million-year journey across the intergalactic void, hitting your camera's digital sensor. Move the slider back in time to see what humanity was doing while these precise photons were rushing towards Earth.
Cosmic Scale: Distance Map Laboratory
Dynamic Linear Scaling & Manipulation: This view builds an interactive, deep-space linear cosmic coordinate system. When swapping objects, the line auto-calculates its limit. Notice how M81 and M82 occupy virtually the same spot—they are physically interacting on a cosmic scale. Use your mouse wheel to zoom in and drag to pan across the axis!