Fireworks (galaxy)

NGC 6946
NGC 6946
	Galaxy
Research history
Discoverer	William Herschel
opening date	September 9, 1798
Designations	NGC 6946 , PGC 65001 , UGC 11597 , MCG 10-29-6 , ZWG 304.6 , Arp 29 , IRAS20338 + 5958
Observational data; ( Age J2000.0 )
Constellation	Swan
Right ascension
Declination
Visible dimensions	11.5 '× 9.8'
Apparent magnitude m V	9.0
Photographic magnitude m B	9.7
Specifications
Type of	Sbc
Redshift	+0.000150 ± 0.000023
Distance	22.5 ± 7.8 million, St. years (6.9 ± 2.4 M pc )
Angular position	57 °
Surface brightness	14.0

NGC 6946 (other designations - PGC 65001 , UGC 11597 , MCG 10-29-6 , ZWG 304.6 , Arp 29 , IRAS20338 + 5958 , Caldwell 12) - a spiral galaxy with a jumper ( SBc ), which is located at a distance of approximately 22 million light-years ^[1] in the constellation Cygnus , on the border with Cepheus . Opened by W. Herschel on September 9, 1798 .

This object is one of those listed in the original edition of the New General Catalog , and is also included in the atlas of peculiar galaxies .

Content

Features

The diameter of the galaxy is about 40 thousand light years across. ^[2] This is more than half the diameter of our Galaxy , which is approximately 100 thousand light years. It is rich in gas and dust clouds, in which intense star formation occurs. In 2015, using the Hubble and Spitzer orbital telescopes, a candidate for stars of the η Kiel type was discovered in the galaxy. ^[3] It is an extremely large and massive star (weighing more than 100 solar masses ).

Upon observation, the image of the galaxy in the sky is very cloudy with the interstellar medium of the Milky Way, since NGC 6946 is close to the galactic plane .

As of May 2017, 10 supernova explosions were detected in this galaxy: SN 1917A , SN 1939C , SN 1948B , SN 1968D , SN 1969P , SN 1980K , SN 2002hh , SN 2004et , SN 2008S ^[4] and SN 2017eaw ^[5] ^[6] . This is a record number of outbreaks that occurred over 100 years. For comparison, in our Galaxy over the past thousand years, only 4 catastrophic explosion of stars were recorded. ^[7] Star N6946-BH1 was discovered in the galaxy , which may have formed a black hole without a supernova burst. ^[eight]

Notes

↑ ¹ ² Distance Results for NGC 6946 (neopr.) . NASA / IPAC Extragalactic Database . Date of treatment June 18, 2010. Archived February 14, 2012.
↑ Fireworks Galaxy NGC 6946 APOD (January 1, 2011). Date of treatment June 10, 2016.
↑ NASA Telescopes Find 'Twins' of Superstar Eta Carinae . NASA (2016-061-01). Date of treatment June 10, 2016.
↑ NGC 6946 (unopened) (unreachable link) . Date of treatment April 3, 2006. Archived April 3, 2006.
↑ ATel # 10372: Confirmation of AT 2017 eaw, a Probable Supernova in NGC 6946 (unspecified) . ATel. Date of appeal May 14, 2017.
↑ ATel # 10376: Spectroscopic Classification of SN 2017 eaw in NGC 6946 as a Young Type IIP Supernova (neopr.) . ATel. Date of appeal May 15, 2017.
↑ Gemini Observatory Welcomes 2005 with Release of Galactic Fireworks Image . Gemini Observatory (December 31, 2005). Date of treatment June 10, 2016.
↑ Collapsing Star Gives Birth to a Black Hole . NASA (May 25, 2017). Date of appeal May 27, 2017.

Literature

Boomsma, R. The disk-halo connection in NGC 6946 and NGC 253 . - Ph.D. thesis . - University of Groningen, 2007.
Joel K. Fridriksson, Jeroen Homan, Walter HG Lewin, Albert KH Kong, and David Pooley. The Long-Term Variability of the X-Ray Sources in NGC 6946 and NGC 4485/4490 (Eng.) // The Astrophysical Journal Supplement Series. - 2008 .-- DOI : 10.1086 / 588817 . - arXiv : 0804.1411 .
Fumi Egusa, Kotaro Kohno, Yoshiaki Sofue, Hiroyuki Nakanishi, and Shinya Komugi. Determining Star Formation Timescale and Pattern Speed in Nearby Spiral Galaxies (Eng.) // The Astrophysical Journal . - 2009. - DOI : 10.1088 / 0004-637X / 697/2/1870 . - arXiv : 0904.3121 .
John Kormendy, Niv Drory, Ralf Bender, and Mark E. Cornell. Bulgeless Giant Galaxies Challenge Our Picture of Galaxy Formation by Hierarchical Clustering // The Astrophysical Journal . - 2010. - DOI : 10.1088 / 0004-637X / 723/1/54 . - arXiv : 1009.3015 .
Rubab Khan, KZ Stanek, JL Prieto, CS Kochanek, Todd A. Thompson, and JF Beacom. Census of Self-obscured Massive Stars in Nearby Galaxies with Spitzer: Implications for Understanding the Progenitors of SN 2008S-like Transients // The Astrophysical Journal . - 2010. - DOI : 10.1088 / 0004-637X / 715/2/1094 . - arXiv : 1001.3681 .
Philip Kaaret, Hua Feng, Diane S. Wong, and Lian Tao. Direct Detection of an Ultraluminous Ultraviolet Source (Eng.) // The Astrophysical Journal . - 2010. - DOI : 10.1088 / 2041-8205 / 714/1 / L167 . - arXiv : 1003.4257 .
EJ Murphy, G. Helou, JJ Condon, E. Schinnerer, JL Turner, R. Beck, BS Mason, R.-R. Chary, and L. Armus. The Detection of Anomalous Dust Emission in the Nearby Galaxy NGC 6946 (Eng.) // The Astrophysical Journal . - 2010. - DOI : 10.1088 / 2041-8205 / 709/2 / L108 . - arXiv : 0912.2731 .
EJ Murphy, JJ Condon, E. Schinnerer, RC Kennicutt, D. Calzetti, L. Armus, G. Helou, JL Turner, G. Aniano, P. Beirão, AD Bolatto, BR Brandl, KV Croxall, DA Dale, JL Donovan Meyer, BT Draine, C. Engelbracht, LK Hunt, C.-N. Hao, J. Koda, H. Roussel, R. Skibba, and J.-DT Smith. Calibrating Extinction-free Star Formation Rate Diagnostics with 33 GHz Free-free Emission in NGC 6946 // The Astrophysical Journal . - 2011. - DOI : 10.1088 / 0004-637X / 737/2/67 . - arXiv : 1105.4877 .
George H. Heald. Magnetic Field Transport from Disk to Halo via the Galactic Chimney Process in NGC 6946 (Eng.) // The Astrophysical Journal . - 2012. - DOI : 10.1088 / 2041-8205 / 754/2 / L35 . - arXiv : 1206.6569 .
Jennifer Donovan Meyer, Jin Koda, Rieko Momose, Masayuki Fukuhara, Thomas Mooney, Sarah Towers, Fumi Egusa, Robert Kennicutt, Nario Kuno, Misty Carty, Tsuyoshi Sawada, and Nick Scoville. Resolved Measurements of X CO in NGC 6946 (Eng.) // The Astrophysical Journal . - 2012. - DOI : 10.1088 / 0004-637X / 744/1/42 . - arXiv : 1109.6272 .
CT Berghea and RP Dudik. Spitzer Observations of MF 16 Nebula and the Associated Ultraluminous X-Ray Source // The Astrophysical Journal . - 2012. - DOI : 10.1088 / 0004-637X / 751/2/104 . - arXiv : 1203.4276 .

Links

Information in English and French from the original “ New General Catalog ”
Information (Eng.) From the Revised New General Catalog
SIMBAD
VizieR (English)
NASA / IPAC Extragalactic Database
List of NGC 6946 publications

[ned-dist-1] ¹ ² Distance Results for NGC 6946 (neopr.) . NASA / IPAC Extragalactic Database . Date of treatment June 18, 2010. Archived February 14, 2012.

[2] Fireworks Galaxy NGC 6946 APOD (January 1, 2011). Date of treatment June 10, 2016.

[3] NASA Telescopes Find 'Twins' of Superstar Eta Carinae . NASA (2016-061-01). Date of treatment June 10, 2016.

[4] NGC 6946 (unopened) (unreachable link) . Date of treatment April 3, 2006. Archived April 3, 2006.

[5] ATel # 10372: Confirmation of AT 2017 eaw, a Probable Supernova in NGC 6946 (unspecified) . ATel. Date of appeal May 14, 2017.

[6] ATel # 10376: Spectroscopic Classification of SN 2017 eaw in NGC 6946 as a Young Type IIP Supernova (neopr.) . ATel. Date of appeal May 15, 2017.

[7] Gemini Observatory Welcomes 2005 with Release of Galactic Fireworks Image . Gemini Observatory (December 31, 2005). Date of treatment June 10, 2016.

[8] Collapsing Star Gives Birth to a Black Hole . NASA (May 25, 2017). Date of appeal May 27, 2017.