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(IAAC) Obj: Markarian 421 - Inst: Vixen 80mm f/15 achromat on GP mount

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Observation Poster: Thomas Jensen <Thomas_Jensen@jubiipost.dk>

Observer: Thomas Jensen
Your skills: Advanced (many years)
Date/time of observation: Feb 20 2004,  21.30 UT
Location of site: Gudhjem, Bornholm, Denmark (Lat 55.14, Elev 70 m.)
Site classification: Rural
Sky darkness: ~6 <Limiting magnitude>
Seeing: IV <1-10 Seeing Scale (10 best)>
Moon presence: None - moon not in sky
Instrument: Vixen 80mm f/15 achromat on GP mount
Magnification: 96X, 133X
Filter(s): None
Object(s): Markarian 421
Category: External galaxy.
Class: BL lacertae object
Constellation: UMa
Data: mag  <12  size ~10"
Position: RA 11:04'  DEC +38:12'
Description:
Markarian 421 is the brightest Active Galactic Nucleus (AGN). It is also classified as a BL Lacertae object (S&T May 1993 p.75). Invisible in a 80mm, right? Wrong!

 This object is incredible easy to locate, mere arcminutes from 6-magnitude 51 UMa. But the close neighborhood with the bright star makes the galaxy difficult to see. The situation reminds me of NGC 404/Beta Andromedae. Nevertheless Markarian 421 has a high surface brightness making it easily visible at 96X (12.5mm ortho) and 133X (9mm ortho) in my 80mm achromat. In fact it was surprisingly easy. It is known to vary in brightness between around 12 to 14 and it surely must have been much closer to 12 than 13 this night.
 133X proved to be best, increasing the distance to the star without dimming Mar 421 to invisibility. I was surprised to see it as a small fuzz since others call it "starlike". A very exciting observation!

Thomas Jensen, Denmark 
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