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Digitized Sky Survey (DSS) Image Information for NGC 6946 | |||
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DSS Acknowledgement , DSS Copyright Notice | DSS Image Generation: 1st Generation DSS Image | ||
Image Center (2000): 20h 34m 52.7s; +60º 09' 11" | Image File Name: n6946.jpg | ||
Image Size (arcminutes): 20' x 20' | Image Size (pixels): 353 x 353 | ||
Original NGC Catalogue Data for NGC 6946 | |||
General Catalogue Designation: 4594 | William Herschel Designation: IV 76 | ||
John Herschel Designation: 2084 | Other Observers: ... | ||
Right Ascension (Equinox 1860): 20h 31m 57s | Annual RA Precession (Equinox 1880): +1.27s | ||
North Polar Declination (Equinox 1860): 30° 20.3' | Annual DEC Precession (Equinox 1880): -12.4" | ||
Summary Description: vF, vL, vg, vsbM, rr | |||
Notes: † | Comments: … | ||
Discovered by: Friedrich Wilhelm Herschel (1738 - 1822) | Year of Discovery: 1798 | ||
Telescope Aperture (Inches): 18.7 | Telescope Type: Reflector | ||
Understanding the 'Summary Description': Summary Description Abbreviations List | |||
Contemporary/Current Data for NGC 6946 | |||
Right Ascension (2000): 20h 34m 52.7s | Declination (2000): +60º 09' 11" | ||
Object Type: Galaxy | Object Classification: Sc I | ||
Constellation: Cygnus | Position Angle: … ° | ||
Visual Magnitude: 9.1 | Surface Brightness: 14.1 | ||
Blue Magnitude: 9.6 | Object Size: 11.5'X9.8' | ||
Also Cataloged As: | UGC 11597, MCG+10-29-006, PGC 65001, H IV-76, h 2084, GC 4594, CGCG 304.006, ARP 29, IRAS 20338+5958 | ||
Catalogue Notes: --------------- | |||
Book / Chart References for NGC 6946 | |||
Luginbuhl & Skiff (Page): 99 | Burnham's (Volume : Page): 1:615 | ||
Uranometria 2000: 32,56 | Herald-Bobroff Astroatlas: C-05,C-06 | ||
Microsky: 145 | GSC Small Region Number: 4246 | ||
POSS Blue Plate #: 598 | POSS Red Plate #: 598 | ||
Database Update Level: 2 (Complete) | |||
Contemporary Visual Observation(s) for NGC 6946 | |||
NGC 6946 = UGC 11597 = MCG +10-29-006 = CGCG 304-006 = Arp 29 20 34 52.3 +60 09 14 V = 08.8; Size 11.5x9.8; SB = 13.8 18" (10/9/04): viewed type II supernova 2004e, discovered 9/27/04 (13 days ago) and appeared at approximately mag 12.8. It was easily identified using a photographic finder chart. The supernova is located 4.1' E and 1.9' S of the nucleus, just west of a pair of mag 13/13.5 stars at 12" separation and was comparable to the brighter star of this pair. A fainter mag 14.4 star is close WSW and the three stars plus supernova form a small wedge of Sagitta shaped group. This is the 8th supernova discovered in N6946 since 1917. 17.5" (8/29/92): bright, very large, 6' diameter to main body, elongated 3:2 ~E- W. Three arms are visible. A long bright arm is attached at the north side of the core and trails to the east. This eastern arm splits; a short fainter branch bends south following the core and a long curving bright arm terminates with a very faint, very small HII knot. On the west side a fainter arm shoots sharply to the north from the core. These outer arms significantly increase the diameter of the main body. The galaxy has a very large brighter middle but the core is just a very small brighter region close SW of the geometric center. A very faint stellar nucleus was seen with direct vision. Observation from 12,000' in the White Mountains. 17.5" (8/13/88): main spiral arm very prominent and easily seen to split. 17.5" (9/14/85): bright, large, brighter central core. A prominent arm attached on the NE side of the core and trailing to the east. This arms splits - the shorter arm is close to the core and a brighter region or arm to the west. 13" (7/27/84): bright arm on the east side highly suspected to branch or split into two arms. Also an arm or brigter region seen on the opposite side of the galaxy pointing W a short way. | |||
Data Sources Used to research NGC 6946 | |||
[NGC] New General Catalogue / [IC] Index Catalogue (Dreyer - 1888, 1895, 1908) [OHCDSO] Observing Handbook and Catalog of Deep-Sky Objects (Luginbuhl & Skiff - 1990) [RE-NGCDDB] NGC Discoverer's Database (Erdmann 1990 - 2006) [UGC] Uppsala General Catalog of Galaxies (Nilson - 1973) [ARP] Atlas of Peculiar Galaxies (H. Arp) [CGCG] Catalog of Galaxies & Clusters of Galaxies (Zwicky - 1968) [MCG] Morphological Catalog of Galaxies (Vorontsov-Velyaminov et al - 1962 thru 1968) [RE-AZDB] The Arizona Database®, V15.5 (Erdmann - 1987 thru 2006) [HC-PPL] NGC/IC Accurate Positions List Database (Corwin - 1996 thru 2006) [SG-NGCO] NGC/IC Observations Database (Gottlieb - 1998 thru 2006) [PGC] Principle Galaxy Catalog (Paturel et al. - 1989, 2003) [DSS] Digitized Sky Survey - 1st (102 CD-ROM) and 2nd (Web Site) Generation (STScI - 1994) [NED] NASA's Extragalactic Database (NED) located at http://nedwww.ipac.caltech.edu/ | |||
Additional Notes | |||
• 1st generation images were generated from the 102 CD-ROM version of the Digitized Sky Survey (DSS) • 2nd generation images were generated at the DSS web site located at http://archive.stsci.edu/cgi-bin/dsswin • Luginbuhl & Skiff page numbers are from 'Observing Handbook and Catalogue of Deep-Sky Objects' by Christian B. Luginbuhl and Brian A. Skiff, produced by Cambridge University Press • Burnham's refers to 'Burnham's Celestial Handbook' in three volumes produced by Dover Publications, Inc. • Uranometria 2000 chart numbers are for those printings authored by Tirion, Rappaport & Lovi, and are not for the most recent printings authored by Tirion, Rappaport & Remaklus in which the charts were re-numbered, all of which were and/or are produced by Willmann-Bell, Inc. • The Herald-Bobroff Astroatlas is by D. Herald and P. Bobroff of Canberra, Australia and is produced by HB2000 Publications • Microsky® is the microfiche rendition of the Palomar Observatory Sky Survey (POSS) produced by Deen Publications (P.O. Box 867088; Plano Texas 75086) • POSS refers to the Palomar Observatory Sky Survey produced by The National Geographic Society in conjunction with The California Institute of Technology • All DSS image annotation was performed by Robert E. Erdmann, Jr., and is ©Copyright 1996 through 2008 by Robert E. Erdmann, Jr. - All rights reserved • All product names, trademarks, and copyrights are the property of their respective owners • Contemporary/Current Data for this object was hand collected and entered from the data sources listed in the "Data Sources Used" section of this table above.- Robert E. Erdmann, Jr. |
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