Flocculent spiral galaxy

A flocculent spiral galaxy is a type of spiral galaxy. Unlike the well-defined spiral architecture of a grand design spiral galaxy, flocculent (meaning "flaky") galaxies are patchy, with discontinuous spiral arms.^[1][2] Self-propagating star formation is the apparent explanation for the structure of flocculent spirals.^[3] Approximately 30% of spirals are flocculent, 10% are grand design, and the rest are referred to as "multi-armed".^[4] The multiple-arm type is sometimes grouped into the flocculent category.^[5]

NGC 2775, a prominent flocculent spiral galaxy

The prototypical flocculent spiral is NGC 2841.^[6]

List of flocculent spiral galaxies

Example	Class	Image	Constellation	Notes
NGC 1325	SBbc		Eridanus
NGC 1353	SBb		Eridanus
NGC 2775	SA(r)ab		Cancer	[7]
NGC 2841	SA(r)b		Ursa Major	[6]
NGC 3521	SAB(r s)bc		Leo	[6]
NGC 4298	SA(r s)c		Coma Berenices
NGC 4414	SA(r s)c		Coma Berenices	[8]
NGC 7793	SA(s)d		Sculptor	[6]
Sunflower Galaxy (Messier 63)	SAB(r s)cd		Canes Venatici	[9]

References

1. COSMOS – SAO Encyclopedia of Astronomy, "Grand Design Spiral" (Retrieved 23 April 2010)
2. COSMOS – SAO Encyclopedia of Astronomy, "Flocculent Spiral" (Retrieved 23 April 2010)
3. Masters, Karen (September 2002), What is the Origin of Spiral Structure in Galaxies, archived from the original on 9 June 2007, retrieved 30 May 2007
4. Case Western Reserve University, Chris Mihos, ASTR222 – Spring 2008, "Spiral Structure" (Retrieved 23 April 2010)
5. University of Virginia, Mark Whittle, ASTR 553/554 : Extragalactic Astronomy (2007), "Lecture 5: Spiral Galaxies" Archived 7 July 2010 at the Wayback Machine (Retrieved 23 April 2010)
6. "A Near-Infrared Atlas of Spiral Galaxies", Debra Meloy Elmegreen, "CH3. Discussion" (Retrieved 23 April 2010)
7. "Hubble Spots Feathered Spiral". NASA. 2 July 2020. Retrieved 3 July 2020.
8. Nemiroff, R.; Bonnell, J., eds. (3 April 2002). "NGC 4414: A Flocculent Spiral Galaxy". Astronomy Picture of the Day. NASA. Retrieved 23 April 2010.
9. NASA (2015). . Retrieved 2 March 2017

Sources

• PDF A Near-Infrared Atlas of Spiral Galaxies, Debra Meloy Elmegreen, 1981, doi:10.1086/190757, Bibcode:1981ApJS...47..229E

External links

• COSMOS astronomy encyclopedia – Flocculent Spiral