USER OBSERVATIONS Last updated: 20 August 2006

Subject:	North America Nebula in ETX70
Sent:	Friday, August 18, 2006 13:54:52
From:	fnr@mail.dk (fnr@mail.dk)
North America Nebula in ETX70
Dr. Clay Sherrod writes about NGC 7000, the North America Nebula: "It is
so large that the brightness is spread over a surface area more than 90
times that of the entire moon! So you are lucky to see it once in a
lifetime.   This object is one in which the ETX 60 and 70 can beat the
rest of them hands down." He is right, but you can beat them more than
once in a lifetime with an OIII filter! I recently acquired "The
Celestial sampler" by Sue French, 2005. The author recommends a short
tube refractor with OIII filter to see NGC 7000. Knowing I was going to
thinly populated "Smaaland" in Southern Sweden for the weekend I packed
the trusty ETX 70, some wide field eyepieces and the "Astronomik" OIII
filter I normally use with my 8" SCT. It was indeed very dark in
Smaaland; I could hardly see the scope in front of me. M31, the
Andromeda galaxy, was clearly visible with the naked eye and the North
America Nebula was unmistakable in the ETX 70 with a 32 mm Televue
ploesll, and even better with 20 mm Meade 4000QX (field of view 4 deg).
I guess it would have looked nice in the 25 mm Meade MA provided with
the scope as well, although the field would have been narrower. North
America was mirror imaged, being brightest in Quebec and Mexico. Florida
was rather faint, but could be seen with averted vision.  Some glow
could be seen even without the OIII filter, but with no definite shape.
The nearby Pelican nebula (IC 5070) was visible too as a diffuse glow
with OIII, but it was difficult to make out any form.

It is often stated that OIII filters are only useful with 8" or bigger
scopes, but that is in fact not true!   - Finn Rasmussen, Copenhagen.

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