NGC 3184, the Little Pinwheel Galaxy, is a spiral galaxy approximately 40 million light-years away in the constellation

Ursa Major Ursa Major (; also known as the Great Bear) is a constellation in the northern sky, whose associated mythology likely dates back into prehistory. Its Latin name means "greater (or larger) bear," referring to and contrasting it with nearby Ursa ...

. It has two

HII region An H II region or HII region is a region of interstellar atomic hydrogen that is ionized. It is typically in a molecular cloud of partially ionized gas in which star formation has recently taken place, with a size ranging from one to hundre ...

s named NGC 3180 and NGC 3181. NGC 3184 houses a high abundance of

heavy element upright=1.2, Crystals of osmium, a heavy metal nearly twice as dense as lead">lead.html" ;"title="osmium, a heavy metal nearly twice as dense as lead">osmium, a heavy metal nearly twice as dense as lead Heavy metals are generally defined as ...

s and SN 1999gi, a

magnitude Magnitude may refer to: Mathematics *Euclidean vector, a quantity defined by both its magnitude and its direction *Magnitude (mathematics), the relative size of an object *Norm (mathematics), a term for the size or length of a vector *Order of ...

Type II supernova A Type II supernova (plural: ''supernovae'' or ''supernovas'') results from the rapid collapse and violent explosion of a massive star. A star must have at least 8 times, but no more than 40 to 50 times, the mass of the Sun () to undergo th ...

detected on December 9, 1999. Other supernovae in NGC 3184 include 1921B (mag 13.5), 1921C (mag 11) and 1937F (mag 13.5). The blue color of its spiral arms comes mostly from relatively few bright young blue stars. The bright stars that highlight the arms were created in huge density waves that circle the

center Center or centre may refer to: Mathematics *Center (geometry), the middle of an object * Center (algebra), used in various contexts ** Center (group theory) ** Center (ring theory) * Graph center, the set of all vertices of minimum eccentrici ...

Structure

NGC 3184 has two prominent spiral arms. They have constant pitch angles, which makes them both symmetrical.

SN 2010dn

On May 31, 2010, Koichi Itagaki detected a

17 optical transient 33" east and 61" north of the center of NGC 3184 at coordinates 10 18 19.89 +41 26 28.8. This event may be an outbursting luminous blue variable (LBV) star. Archival Hubble and

Spitzer Spitzer is a surname. Notable people with the surname include: * Andre Spitzer (1945–1972), Israeli fencing coach and victim of the Munich massacre * Bernard Spitzer (1924–2014), American real estate developer and philanthropist, father of Eli ...

images of NGC 3184 seem to show no progenitor for optical transient SN 2010dn. SN 2010dn is just like SN 2008S and NGC 300-OT. On day 2, SN 2010dn had an unfiltered magnitude of 17.1, corresponding to a peak

absolute magnitude Absolute magnitude () is a measure of the luminosity of a celestial object on an inverse logarithmic astronomical magnitude scale. An object's absolute magnitude is defined to be equal to the apparent magnitude that the object would have if it ...

of roughly -13.3. 2010dn-NGC3184-2010Jun01

References

External links

*
Spiral Galaxy NGC 3184 & Supernova 1999gi
(20-inch F/8.1 Ritchey Chretien Cassegrain)

(supernovae.net) * Discovery image o
SN2010dn
(2010-05-31 mag 17.5) / Wikisk
DSS2
an
SDSS
zoom-in of the same region {{Ngc35 Galaxies discovered in 1787 3184 05557 Unbarred spiral galaxies Ursa Major (constellation) 17870318 19991209 030087

Structure

SN 2010dn

See also

References

External links