[Prev][Next][Index][Thread]
(IAAC) Re: Pothier naked-eye objects
Brian is not a current IAAC subscriber. If you follow up, please MANUALLY put
'bas@lowell.edu' in the "Cc:" line of your reply! Forwarded sans permission.
Lew Gramer <owner-netastrocatalog@jovian.com>
------- Forwarded Message
Date: Sat, 1 Jan 2000 13:44:13 -0700 (MST)
From: Brian Skiff <bas@lowell.edu>
To: WebbSoc@listbot.com
Subject: Re: Pothier naked-eye objects
The Webb Society - http://www.webbsociety.freeserve.co.uk
Several weeks ago Yann Pothier posted a list of presumed naked-eye
objects visible from northern latitudes. This is something I've thought about,
too, and having ready access to true-dark sky I have spent several years making
observations to test various candidates. I append below Yann's list (with all
but the names trimmed out), with added comments. Several objects in Yann's
list are shown twice under different names, and many of the Collinder clusters
simply are not real or much too sparse to be considered "deep-sky objects".
Some objects are simply too faint, and published total magnitudes for some
clusters include a single bright star or two, but one would not see these as
clusters visually.
Following from discussions elsewhere, I have posted an all-sky list of
certain or near-certain naked-eye objects at the Lowell ftp area:
ftp://ftp.lowell.edu/pub/bas/deepsky/naked.dso
...to which I may add a few new ones based on Yann's suggestions.
Although many of the objects are easy or straightforward from a true-dark
site, in the marginal cases one must be very careful to sort out neigbouring
mag. 7 and 8 stars in order to make sure you've found the correct object. It
makes one's claim more useful if such details are provided as well. I can post
a discussion of what was necessary to identify M81, for example, if desired.
I was pleased to see that Yann included Sharpless 264 (Sh2-264), the
very large nebula surrounding the lambda Orionis group. I find this readily
visible from the Lowell Anderson Mesa site, but I don't think anyone's ever
mentioned it in print being a naked-eye object. On the other hand I have
never convinced myself that I could see Barnard's Loop because there are so
many faint stars strung along it that can mimic nebulosity. Still again, the
Rosette Nebula is pretty easy to see even from a somewhat light-polluted
site when using a UHC or [OIII] filter. This is a good target to start your
challenging naked-eye viewing with, since the change in the size of the object
going from unfiltered to filtered is dramatic.
\Brian
==================================
Blanco 1 too sparse
Cr 065 not real
Cr 069 lambda Ori cluster, easy
Cr 070 Belt of Orion, easy
Cr 089 not real
Cr 106 not real
Cr 121 too sparse
Cr 132 too sparse
Cr 135 too sparse
Cr 140 too sparse
Cr 316 = Trumpler 24 (preferred name)
Cr 399 easy; Brocchi's cluster = Coathanger
Cr 464 not real
IC 0348 too faint
IC 1396 nebula readily visible
IC 1805 nebula too faint
IC 1848 nebula too faint
IC 4665 straightforward
IC 4725 = M25; easy
IC 4756 readily visible
IC 4996 too faint, too small
M002 probably visible
M003 straightforward
M004 easy
M005 straightforward
M006 easy
M007 easy
M008 easy
M011 easy
M012 probably visible
M013 easy
M015 straightforward
M016 straightforward
M017 straightforward
M018 too faint
M020 easy
M021 straightforward
M022 easy
M023 easy
M024 = IC 4715; easy
M025 = IC 4725 above
M028 background too bright?
M029 too small/faint
M031 easy
M033 straightforward
M034 easy
M035 easy
M036 straightforward
M037 straightforward
M038 straightforward
M039 straightforward
M041 easy
M042 easy
M044 easy
M045 Pleaides
M046 straightforward
M047 straightforward
M048 straightforward
M050 straightforward
M052 maybe too faint
M062 background too bright?
M067 straightforward
M081 tough but visible
M092 faint
M093 straightforward
Mel 020 = alpha Persei cluster
Mel 022 = Pleiades
Mel 111 = Coma Berenices cluster
NGC 0253 reportedly visible from the south
NGC 0281 too faint
NGC 0752 easy
NGC 0869 easy
NGC 0884 easy
NGC 1499 visible with filter
NGC 1746 straightforward
NGC 1981 straightforward
NGC 2232 brightest star only
NGC 2237 Rosette Nebula, visible with filter
NGC 2244 Rosette cluster, easy
NGC 2264 brightest star only
NGC 2451 easy
NGC 2546 easy
NGC 5128 reportedly visible from south
NGC 6124 straightforward
NGC 6231 easy
NGC 6530 = M 8
NGC 6633 easy
NGC 6871 too small/faint
NGC 7000 North America Nebula; straightforward
NGC 7243 background too bright?
NGC 7293 several reports (without filters!)
Sh2-264 lambda Ori nebula, straightforward (much easier than Barnard's Loop!)
Sh2-276 Barnard's Loop; often confused with encircling mag 5-7 stars
Steph 01 delta Lyr cluster; brightest star only
Stock 02 bright background, barely discernable
Tr 10 probably visible, but in very crowded area
______________________________________________________________________
Start Your Own FREE Email List at http://www.listbot.com/links/joinlb
------- End of Forwarded Message
To UNSUBSCRIBE from the 'netastrocatalog' lists, use the Web form at:
http://www.tiac.net/users/lewkaren/netastrocatalog/subscribe.html