Constellation of the Month: April
Ursa Major (The Great Bear)

by: John Mirtle.
Page last updated: May 3, 2004

Contents
Naked Eye Objects    Small Scope Objects    Big Scope Objects    Challenge Objects    Maps    Photos

Naked Eye Objects:

Name R.A. Decl. Details
  Ursa Major Moving Cluster . . "The Big Dipper" - the nearest open cluster, 70LY distant, 17 stars, possibly including a Corona Borealis.
  z UMa (Mizar) . . The middle star in the handle of the dipper, magnitude 2.5. Forms an optical double with Alcor 11.8 arc minutes away in P.A. 72° and has been used for centuries as an eyesight test. Zeta is a true double with a mag 4.0 companion 14.4 arc seconds away in P.A. 151°.
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Small Scope Objects:

Name R.A. Decl. Details
  M40 12hr 22.4m +58° 05' "Winnecke 4" - a double star, components are mag. 9.0 and 9.3. Separation of 50.1 arc seconds in P.A. 83°. The most disappointing of the Messier objects.
  M81!
(NGC 3031)		 09hr 55.6m +69° 04' A bright mag 7.9 Sb spiral galaxy, 2.3 megaparsecs distant. Covers 10 x 18 arc minutes and is visible in binoculars from a good viewing site.
  M82!
(NGC 3034)		 09hr 55.8m +69° 41' Another bright galaxy, only 38 arc minutes from M81. An edge-on irregular galaxy, mag 9.3, 8 x 3 arcminutes in size. Look for dark patches with larger 'scopes.
  M101!
(NGC 5457)		 14hr 03.2m +54° 21' The "Pinwheel Galaxy" - a large, face-on Sc spiral , 22 x 20 arc minutes, mag 8.2. Difficult to observe due to low surface brightness. Sky conditions more important than aperture.
  M108
(NGC 3556)		 11hr 11.5m +55° 40' A bright, near edge-on Sc galaxy. Mag 10.7, 7.8 x 1.4 arc minutes. Very high surface brightness, shows dark patches and mottling in larger scopes. Near b UMa.
  M109
(NGC 3992)		 11hr 57.6m +53° 23' An SBb barred spiral galaxy 40 arc minutes SE from g UMa. Mag 10.6, 6.4 x 3.5 arc minutes. Shows spiral structure easily in larger scopes.
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Big Scope Objects:

Name R.A. Decl. Details
  M97!
(NGC 3587)		 11hr 14.8m +55° 01' The "Owl Nebula" - a magnitude 12 planetary nebula, 180 arc seconds in diameter, giving low surface brightness. Central star is 14th mag. Responds well to UHC or OIII filters, look for two dark patches in larger scopes which give it it's nickname. 48 arc min SE of M108.
  NGC 2976 09hr 47m +67° 54' Small, bright Sb/Sd galaxy near M81. Mag 10.9, 3.4 x 1.3 arc minutes.
  NGC 3953 11hr 54m +52° 20' A bright SBb spiral, south of M109. Mag 10.8, 6 x 2.8 arc minutes
  NGC 2841!! 09hr 22.0m +50° 58' A near edge-on Sb spiral. Mag 9.3, 8.1 x 3.8 arc minutes. (110NGC)
  NGC 3079! 10hr 02.2m +55° 41' A mag 10.6 edge-on Sb spiral, 7.6 x 1.7 arc minutes. (110NGC)
  NGC 3184! 10hr 18.3m +41° 25' A low surface brightness face-on Sc spiral. Mag 9.7, 6.8 x 6.8 arc minutes. (110NGC)
  NGC 3877! 11hr 46.1m +47° 30' Edge-on Sb spiral. Mag 10.9, 5.4 x 1.5 arc minutes. (110NGC)
  NGC 3941! 11hr 52.9m +36° 59' A small bright E3 elliptical, mag 9.8, 3.8 x 2.5 arc min. (110NGC)
  NGC 4026! 11hr 59.4m +50° 58' Lens shaped S0 galaxy near g UMa. Mag 10.7, 5.1x1.4 arc min (110NGC)
  NGC 4088! 12hr 05.6m +50° 33' Sc galaxy, mag 10.5, 5.8 x 2.5 arc minutes. Unusual mottling in larger scopes. Look for NGC 4085 in the same low power field. (110NGC)
  NGC 4157! 12hr 11.1m +50° 29' Edge-on Sb spiral, near NGC 4088. Mag 11.9, 6.9x1.7 arc min. (110NGC)
  NGC 4605! 12hr 40.0m +61° 37' Near edge-on SBcp spiral, mag 9.6, 5.5 x 2.3 arc min. (110NGC)
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Challenge Objects:

Name R.A. Decl. Details
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Constellation Maps:

Lines No Lines Reverse Reverse No Lines


Lines No Lines Reverse Reverse No Lines No Map

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Photos:


 
Photo 1
South is at top to match the view in an inverting telescope.
Photo credit: John Mirtle.
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