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(IAAC) Netastrocatalog! [Obj: M76 (Little Dumbbell) - Inst: Newt 20" f/5]
[
One of the email mailing lists I administer is for the Internet Amateur
Astronomers Catalog or "netastrocatalog", a volunteer list that is aimed at
sharing and archiving the deep-sky observations of amateurs at all levels
of experience, with the aim of helping newer observers "learn how to see"
better, and allowing more experienced amateurs to share their memorable
observing experiences with other. Below is a sample of an entry I submitted
from a session on Friday night. The IAAC is open to anyone on the Internet,
and your contributions to it would be VERY WELCOME! Let me know if any of
you are interested, and clear skies!
-Lew
]
Observer: Lew Gramer
Your skills (Beginner, Intermediate, Advanced): Intermediate
Date and UT of Observation: 1997-1-10/11, 03:30 UT
Location: Topsfield, MA, USA (42N)
Site classification (urban, suburban, rural): semirural
Limiting magnitude: 5.9 visual
Seeing: 2 - good
Moon up: no
Instrument: Newt Reflector 20" f/5 (dob)
Magnification: 70x, 210x, 360x (all Nagler designs)
Filters used: None, OIII
Object: M76 (Little Dumbbell)
Category: Planetary nebula
Constellation: Per
Data: mag 12.2 size 65" (halo: 5')
RA/DE: 1h42m +51o34m
Description:
This planetary is easily found from Theta Per using a wide-field
eyepiece, presenting its beautiful, bright two-lobed shape very
clearly at 70x. Higher power (210x) shows some fainter areas of
nebulosity at each end, forming the classic shape from photos.
At 210x and 360x, the WNW is noticeably the brighter of the two
lobes, and also more smoothly sperical than its counterpart to S.
The ESE lobe is a little less than 0.5 mag dimmer in surface
brightness, with the strong impression of a peaked "anvil" shape
pointing NE on its long axis. With an OIII filter at the higher
magnifications, still more nebulosity is apparent on both sides,
and especially beyond and S of the fainter ENE lobe, apparently
also streaming off (into outer halo?) from the central region.
The central "connecting" region is often missed for some reason,
but on this night was clearly defined between the lobes.
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Karen Simmons & Lew Gramer dedalus@alum.mit.edu http://www.tiac.net/users/lewkaren
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