Merrill 2-1
Planetary Nebula
aka Me 2-1, PNG 342.1+27.5, PK 342+27.1, He 2-126, ARO 88, ESO 514-12
Integrated Visual Magnitude: 11.6
Apparent Diameter: 6"
Magnitude of Central Star: 17.3
Mean Surface Brightness: 15.2 mag/arc-sec2
Distance: 16,000 ly

Minimum requirements to detect: 6-inch scope under country skies


Merrill 2-1 is an obscure planetary nebula in Libra -- a constellation with remarkably few deep sky objects of note.  This planetary is bright, but very, very small.  An experienced observer should be able to pick it out as a sort of "funny looking star", but only at 150x or more.  So don't be shy about using high magnification. 

One thing that really helps in finding this tiny planetary is that it lies about an arc minute to the east of a 9.8 magnitude star, SAO 183407.  This is a rather red (K2) star with a B-V color of 1.2.  The nearby star makes finding this one easy and provides an excellent opportunity to experience the subtle difference in appearance between a tiny planetary nebula and a star.  Even if the subtle blue-green hue of a planetary nebula is not readily apparent, your eye will still tell you that something is "funny" about the planetary nebula.  This is a good instinct to hone because it can help you quickly pick out a tiny planetary in a crowded star field.

In my 18-inch f/4.5 at 97x I was easily able to pick out the apparent pair of stars, the fainter of which I knew would be Me 2-1.  But it wasn't until I applied more magnification that I was able to pick up the "funny" appearance of the planetary.  Even at 270x, it still appeared nearly starlike.  The slight blue-gray color was becoming quite apparent.  It wasn't until I applied 430x that the oval shape appeared, with a faint star at its center.  The faint star would pop in and out of view as I watched. 

There is a little 13th magnitude, face-on barred spiral galaxy in the field to the west.  It appeared to me as a very faint, extraordinarily diffuse oval.  This galaxy is so diffuse that no brightening at all could be detected toward the center and the entire oval could only be described as "almost not there."


The field in an 8-inch f/8 at 75x.  North is down and east is to the right.
Millennium Star Atlas Vol II Chart 860
Sky Atlas 2000 Chart 21
Uranometria 2000 Vol II Chart 334

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