9/25/2014 Pinwheel - Wikipedia, the free encyclopedia Coordinates: 14h 03m 12.6s, +54° 20′ 57″ From Wikipedia, the free encyclopedia

The Pinwheel Galaxy (also known as Messier 101, M101 or NGC 5457) is a face-on distanced 21 million light-years (six megaparsecs)[2] away in the , first Pinwheel Galaxy discovered by Pierre Méchain on March 27, 1781, and communicated to who verified its position for inclusion in the Messier Catalogue as one of its final entries.

On February 28, 2006, NASA and the ESA released a very detailed image of the Pinwheel Galaxy, which was the largest and most detailed image of a galaxy by at the time.[7] The image was composed from 51 individual exposures, plus some extra ground-based photos.

On August 24, 2011, a Type Ia , SN 2011fe, was discovered in M101.

Contents

1 Discovery Observation data (J2000 epoch) 2 Structure and composition Constellation Ursa Major 3 Companion Right ascension 14h 03m 12.6s

4 Supernova Declination +54° 20′ 57″ 5 See also 0.000804 6 References Helio 241 ± 2 km/s 7 External links Distance 20.9 ± 1.8 Mly (6.4 ± 0.5 Mpc) Type SAB(rs)cd Discovery Apparent 28′.8 × 26′.9 dimensions (V) Apparent 7.86 http://en.wikipedia.org/wiki/Pinwheel_Galaxy 1/7 9/25/2014 Pinwheel Galaxy - Wikipedia, the free encyclopedia

Pierre Méchain, the discoverer of Messier 101, described it as a " without , very obscure magnitude (V) and pretty large, 6' to 7' in diameter, between the left hand of Bootes and the tail of the great Bear. It Other designations is difficult to distinguish when one lits the [grating] wires."[8] Messier 101, M101, NGC 5457, UGC 8981, PGC William Herschel noted in 1784 that "[M101] in my 7, 10, and 50063, Arp 26 20-feet [focal length] reflectors shewed a mottled kind of nebulosity, which I shall call resolvable; so that I expect my References: [1][2][3][4][5][6] present telescope will, perhaps, render the visible of which I See also: Galaxy, suppose them to be composed."[8]

The Pinwheel Galaxy Lord Rosse observed M101 in his 72-inch diameter Newtonian reflector during the second half of the 19th century. He was the first to make extensive note of the spiral structure and made several sketches.[8]

To observe the spiral structure in modern instruments requires a fairly large instrument, very dark skies, and a low power eye piece. Structure and composition

M101 is a relatively large galaxy compared to the . With a diameter of 170,000 light-years it is seventy percent larger than the Milky Way. It has a disk mass on the order of 100 billion solar masses, along with a small central bulge of about 3 billion solar masses.[9]

M101 is noted for its high population of H II regions, many of which are very large and bright. H II regions usually accompany the enormous clouds of high density molecular hydrogen gas contracting under their own gravitational force where stars form. H II regions are ionized by large numbers of extremely bright and hot young stars; those in M101 are capable of creating hot superbubbles.[10] In a 1990 study, 1264 H II regions were [11] cataloged in the galaxy. Three are prominent enough to receive numbers - NGC Combined infrared, visible, and x-ray 5461, NGC 5462, and NGC 5471.[12] images of M101 showing that both young and old stars are evenly M101 is a asymmetrical due to the tidal forces from interactions with its companion galaxies. These gravitational distributed along the tightly-wound interactions compress interstellar hydrogen gas, which then triggers strong activity in M101's spiral arms. spiral arms that can be detected in ultraviolet images.[13]

http://en.wikipedia.org/wiki/Pinwheel_Galaxy 2/7 9/25/2014 Pinwheel Galaxy - Wikipedia, the free encyclopedia In 2001, the x-ray source P98, located in M101, was identified as an ultra-luminous X-ray source - a source more powerful than any single star but less powerful than a whole galaxy - using the Chandra X-ray Observatory. It received the designation M101 ULX-1. In 2005, Hubble and XMM-Newton observations showed the presence of an optical counterpart, strongly indicating that M101 ULX-1 is an x-ray binary.[14] Further observations showed that the system deviated from expected models - the is just 20 to 30 solar masses, and consumes material (including captured stellar wind) at a higher rate than theory suggests.[15] Companion galaxies

M101 has five prominent companion galaxies: NGC 5204, NGC 5474, NGC 5477, NGC 5585, and Holmberg IV.[16] As stated above, the gravitational interaction between M101 and its satellites may have triggered the formation of the grand design pattern in M101. M101 has also probably distorted the companion galaxy NGC 5474.[16] M101 and its companion galaxies comprise most or possibly all of the .[17][18][19][20] Supernova

On August 24, 2011, a Type Ia supernova, SN 2011fe, initially designated PTF 11kly, was discovered in M101. The supernova was visual magnitude 17.2 at discovery and reached magnitude 9.9 at its peak.[21][22][23] This was the fourth supernova recorded in M101. The first, SN 1909A, was discovered by Max Wolf in January 1909 and reached magnitude 12.1. SN 1951H reached magnitude 17.5 in September 1951 and SN 1970G reached magnitude 11.5 in January 1970.[24]

Type Ia supernova SN 2011fe

See also

Messier 74 – a similar face-on spiral galaxy – a similar face-on spiral galaxy that is sometimes called the Southern Pinwheel Galaxy Messier 99 – a similar face-on spiral galaxy

http://en.wikipedia.org/wiki/Pinwheel_Galaxy 3/7 9/25/2014 Pinwheel Galaxy - Wikipedia, the free encyclopedia – another galaxy sometimes called the Pinwheel Galaxy

References

1. ^ "NASA/IPAC Extragalactic Database" (http://nedwww.ipac.caltech.edu/cgi-bin/nph-objsearch?objname=Messier+101&img_stamp=yes&extend=no). Results for Messier 101. Retrieved 2006-12-06. 2. ^ a b Shappee, Benjamin; Stanek, Kris (June 2011). "A New Cepheid Distance to the Giant Spiral M101 Based on Image Subtraction of Hubble Space Telescope/Advanced Camera for Surveys Observations". Astrophysical Journal 733 (2): 124. arXiv:1012.3747 (https://arxiv.org/abs/1012.3747). Bibcode:2011ApJ...733..124S (http://adsabs.harvard.edu/abs/2011ApJ...733..124S). doi:10.1088/0004-637X/733/2/124 (http://dx.doi.org/10.1088%2F0004- 637X%2F733%2F2%2F124). 3. ^ R. W. Sinnott, ed. (1988). The Complete New General Catalogue and Index Catalogue of Nebulae and Star Clusters by J. L. E. Dreyer. Sky Publishing Corporation / Cambridge University Press. ISBN 0-933346-51-4. 4. ^ "Distance Results for Messier 101" (http://nedwww.ipac.caltech.edu/cgi-bin/nDistance?name=MESSIER+101). NASA/IPAC Extragalactic Database. Retrieved 2010-05-01. 5. ^ "SIMBAD-M101" (http://simbad.u-strasbg.fr/simbad/sim-id?Ident=M101). SIMBAD Astronomical Database. Retrieved 2009-11-29. 6. ^ Armando, Gil de Paz; Boissier; Madore; Seibert; Boselli; et al. (2007). "The GALEX Ultraviolet Atlas of Nearby Galaxies". Astrophysical Journal Supplement 173 (2): 185–255. arXiv:astro-ph/0606440 (https://arxiv.org/abs/astro-ph/0606440). Bibcode:2007ApJS..173..185G (http://adsabs.harvard.edu/abs/2007ApJS..173..185G). doi:10.1086/516636 (http://dx.doi.org/10.1086%2F516636). 7. ^ HubbleSite – NewsCenter – Hubble's Largest Galaxy Portrait Offers a New High-Definition View (02/28/2006) – Introduction (http://hubblesite.org/newscenter/newsdesk/archive/releases/2006/10/) 8. ^ a b c SEDS Historical Notes (http://messier.seds.org/Mdes/dm101.html) 9. ^ Comte, G., Monnet, G., & Rosado, M.; Monnet; Rosado (1979). "An optical study of the galaxy M 101 - Derivation of a mass model from the kinematic of the gas". Astronomy and Astrophysics 72: 73–81. Bibcode:1979A&A....72...73C (http://adsabs.harvard.edu/abs/1979A&A....72...73C). 10. ^ Immler, Stefan and Wang, Q. Daniel (2001). "ROSAT X-Ray Observations of the Spiral Galaxy M81" (http://iopscience.iop.org/0004-637X/554/1/202/). The Astrophysical Journal 554 (1): 202. arXiv:astro-ph/0102021 (https://arxiv.org/abs/astro-ph/0102021). Bibcode:2001ApJ...554..202I (http://adsabs.harvard.edu/abs/2001ApJ...554..202I). doi:10.1086/321335 (http://dx.doi.org/10.1086%2F321335). Retrieved 12 May 2014. 11. ^ Hodge, Paul W. et al; Gurwell, Mark; Goldader, Jeffrey D.; Kennicutt, Robert C., Jr. (August 1990). "The H II regions of M101. I - an atlas of 1264 emission regions". Astrophysical Journal Supplement Series 73: 661–670. Bibcode:1990ApJS...73..661H (http://adsabs.harvard.edu/abs/1990ApJS...73..661H). doi:10.1086/191483 (http://dx.doi.org/10.1086%2F191483).

http://en.wikipedia.org/wiki/Pinwheel_Galaxy 4/7 9/25/2014 Pinwheel Galaxy - Wikipedia, the free encyclopedia 12. ^ Giannakopoulou-Creighton, J.; Fich, M.; Wilson, C. D. (1999). "Star formation in the giant HII regions of M101". The Astrophysical Journal 522: 238. arXiv:astro-ph/9903334 (https://arxiv.org/abs/astro-ph/9903334). Bibcode:1999ApJ...522..238G (http://adsabs.harvard.edu/abs/1999ApJ...522..238G). doi:10.1086/307619 (http://dx.doi.org/10.1086%2F307619). 13. ^ Waller, William H. et al; Bohlin, Ralph C.; Cornett, Robert H.; Fanelli, Michael N.; Freedman, Wendy L.; Hill, Jesse K.; Madore, Barry F.; Neff, Susan G.; Offenberg, Joel D.; O'Connell, Robert W.; Roberts, Morton S.; Smith, Andrew M.; Stecher, Theodore P. (20 May 1997). "Ultraviolet Signatures of Tidal Interaction in the Giant Spiral Galaxy M101" (http://iopscience.iop.org/0004-637X/481/1/169). The Astrophysical Journal 481 (1): 169. arXiv:astro-ph/9612165 (https://arxiv.org/abs/astro-ph/9612165). Bibcode:1997ApJ...481..169W (http://adsabs.harvard.edu/abs/1997ApJ...481..169W). doi:10.1086/304057 (http://dx.doi.org/10.1086%2F304057). Retrieved 12 May 2014. 14. ^ Kuntz, K.D. et al (10 February 2005). "The Optical Counterpart of M101 ULX-1" (http://iopscience.iop.org/1538-4357/620/1/L31/fulltext/19014.text.html). The Astrophysical Journal 620 (1): L31–L34. Bibcode:2005ApJ...620L..31K (http://adsabs.harvard.edu/abs/2005ApJ...620L..31K). doi:10.1086/428571 (http://dx.doi.org/10.1086%2F428571). Retrieved 12 May 2014. 15. ^ Liu, Jifeng; Bregman, Joel N.; Bai, Yu; Justham, Stephen; Crowther, Paul (2013). "Puzzling accretion onto a black hole in the ultraluminous X-ray source M101 ULX-1". Nature 503 (7477): 500. arXiv:1312.0337 (https://arxiv.org/abs/1312.0337). Bibcode:2013Natur.503..500L (http://adsabs.harvard.edu/abs/2013Natur.503..500L). doi:10.1038/nature12762 (http://dx.doi.org/10.1038%2Fnature12762). 16. ^ a b A. Sandage, J. Bedke (1994). Carnegie Atlas of Galaxies. Carnegie Institution of Washington. ISBN 0-87279-667-1. 17. ^ R. B. Tully (1988). Nearby Galaxies Catalog. Cambridge University Press. ISBN 0-521-35299-1. 18. ^ P. Fouque, E. Gourgoulhon, P. Chamaraux, G. Paturel; Gourgoulhon; Chamaraux; Paturel (1992). "Groups of galaxies within 80 Mpc. II – The catalogue of groups and group members". Astronomy and Astrophysics Supplement (2nd ed.) 93: 211–233. Bibcode:1992A&AS...93..211F (http://adsabs.harvard.edu/abs/1992A&AS...93..211F). 19. ^ A. Garcia (1993). "General study of group membership. II – Determination of nearby groups". Astronomy and Astrophysics Supplement 100: 47–90. Bibcode:1993A&AS..100...47G (http://adsabs.harvard.edu/abs/1993A&AS..100...47G). 20. ^ G. Giuricin, C. Marinoni, L. Ceriani, A. Pisani; Marinoni; Ceriani; Pisani (2000). "Nearby Optical Galaxies: Selection of the Sample and Identification of Groups". Astrophysical Journal 543 (1): 178–194. arXiv:astro-ph/0001140 (https://arxiv.org/abs/astro-ph/0001140). Bibcode:2000ApJ...543..178G (http://adsabs.harvard.edu/abs/2000ApJ...543..178G). doi:10.1086/317070 (http://dx.doi.org/10.1086%2F317070). 21. ^ Nugent, Peter et al (24 August 2011). "Young Type Ia Supernova PTF11kly in M101" (http://www.astronomerstelegram.org/?read=3581). The Astronomer's Telegram. Retrieved 25 August 2011. 22. ^ Nugent, Peter et al. "Supernova Caught in the Act" (http://www.nersc.gov/news-publications/science-news/2011/supernova-caught-in-the-act/). Retrieved 7 September 2011. 23. ^ Hartmut Frommert and Christine Kronberg (15 Sep 2011). "Supernova 2011fe in M101" (http://messier.seds.org/more/m101_sn2011fe.html). Retrieved 17 Sep 2011. http://en.wikipedia.org/wiki/Pinwheel_Galaxy 5/7 9/25/2014 Pinwheel Galaxy - Wikipedia, the free encyclopedia 24. ^ Stoyan, Ronald Atlas of the Messier Objects, Cambridge University Press 2008 page 329

External links

The Pinwheel Galaxy on WikiSky: DSS2 (http://www.wikisky.org/? Wikimedia Commons has object=Pinwheel+Galaxy&img_source=DSS2), SDSS (http://www.wikisky.org/? media related to Pinwheel Galaxy. object=Pinwheel+Galaxy&img_source=SDSS), GALEX (http://www.wikisky.org/? object=Pinwheel+Galaxy&img_source=GALEX), IRAS (http://www.wikisky.org/?object=Pinwheel+Galaxy&img_source=IRAS), Hydrogen α (http://www.wikisky.org/?object=Pinwheel+Galaxy&img_source=HALPHA), X-Ray (http://www.wikisky.org/? object=Pinwheel+Galaxy&img_source=RASS), Astrophoto (http://www.wikisky.org/?object=Pinwheel+Galaxy&img_source=IMG_all), Sky Map (http://www.wikisky.org/?object=Pinwheel+Galaxy), Articles and images (http://www.wikisky.org/starview?object=Pinwheel+Galaxy) Messier 101, SEDS Messier pages (http://messier.seds.org/m/m101.html) Extremely detailed picture of the Pinwheel Galaxy at HubbleSite.org (http://hubblesite.org/newscenter/newsdesk/archive/releases/2006/10/image/a) Pinwheel Galaxy at ESA/Hubble (http://www.spacetelescope.org/images/html/heic0602a.html) Spiral Galaxy Messier 101 (Pinwheel Galaxy) (http://ryutao.main.jp/english/st2k_m101_mt200.html) Picture of the day on APOD on April 14, 2009 (http://apod.nasa.gov/apod/ap090414.html) Harutyunyan, Avet; Merrifield, Mike; Dhillon, Vik. "M101 – Pinwheel Galaxy" (http://www.deepskyvideos.com/videos/messier/M101_pinwheel.html). Deep Space Videos. Brady Haran. Pinwheel Galaxy (Messier 101) at Constellation Guide (http://www.constellation-guide.com/pinwheel-galaxy-messier-101/) Pinwheel Galaxy, Messier 101 (http://www.astrodwarf.com/deep-sky/detail/9355)

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Categories: Spiral galaxies Intermediate spiral galaxies M101 Group Ursa Major (constellation) Messier objects NGC objects UGC objects PGC objects Arp objects Astronomical objects discovered in 1781 Objects within 100 Mly of Earth http://en.wikipedia.org/wiki/Pinwheel_Galaxy 6/7 9/25/2014 Pinwheel Galaxy - Wikipedia, the free encyclopedia

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