Nearly looking like twins,these two Leo-Galaxies really resemble each other.Each is sized about 3,2′ × 2,5´ and shining with 13mag visual brightness.
Their structure is a bit different:NGC3684 is SA(rs)bc-typed galaxy,NGC3686 a barred spiral of type SB(s)bc.Their real distance is equal: 49 mio light-years away.
Both galaxies have a lot of starburst regions,which emitt a lot of Halpha-light.
Quite different are their discovery-dates;NGC3684 was first seen by John Herschel in 1831,while NGC3686 was discovered 47 years earlier by William Herschel.
position (epoch 2000):
Ra.: 11h 27m 11,2s
Decl.: +17° 01′ 49″
Ra.: 11h 27m 44.0s
Decl.: +17°13′ 27″
LRGB image with L = 21x1200s, RGB = 6x1200s each,a total of 13.0 hours
80cm f/7 AstroOptik Keller corrected cassegrain FLI Proline 16803 Astrodon LRGB Gen-II filters
Prompt 7 CTIO/UNC Chile,remote controlled
image processing: Bernd Flach-Wilken
Here you see the two Leo-GXs (the upper one NGC3686,the lower one NGC3684) in a 21.8´ squared FOV.
For full resolution click HERE