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Old 10-03-2014, 01:48 AM
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Weltevreden SA (Dana)
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I see it because I know where it is (?)

Is there such a thing as doing too much research before going after a tough visual object? By the time eyepiece hour begins, I've read every report and technical paper about the thing. I know what to look for, and where. I'm wondering if this is such a good idea. This past dark moon cycle was the best harvest of difficult objects ever, all faint globulars or dwarfs. Among the former was a half hour looking for Pal 3 at the exact spot near Alpha Sextans where observer images showed it. Warmer-uppers such as nearby Sextans A and B were easy. The ten remote LMC globulars in Mensa required patience but all showed up with enough looking, down to mag 14.2 IC 2158. But Pal 3? Now I dunno. I was sure I saw it, but Barbara Wilson & Doug Snyder's observations call it tough in their 18" and 20" gear. My best deep sky hunter is only 8 inches, though my skies add another 4 inches to the effective limit.

So have any of you ever fooled yourself into thinking you saw a tough object that other observer reports indicate that we may be seeing what we want to?

=Dana in S Africa
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Old 10-03-2014, 03:31 AM
glend (Glen)
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Wishful seeing, the horsehead fooled me a few times until I unexpectedly ran over it. Yes i would agree being over prepared creates a mindset or expectation.
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Old 10-03-2014, 09:46 AM
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Wishful seeing....
Love it Glen! I have quite a few 'wishful seeing' occurrences too. Suppose it's something you can't avoid because you really need a high level of preparation to attempt very faint objects, including precise position. I apply a rough rule:

*If you think you saw it, you didn't.*

It takes a lot of work to tease out an extremely faint one (limit of vision stuff) and a positive sighting has to pass a lot of individual tests along the way!

Cheers -
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Old 10-03-2014, 10:09 AM
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Weltevreden SA (Dana)
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Positive sighting before logging

Thanks for the caveat, Rob K. My usual criterion is three repeats of a sighting on the same night on three different occasions. If possible, on two different scopes, 180mm and 200mm in my case. Many times the 180 won't reveal what the 200 does, even though the 180 has superior optics.

I'm going to start a new thread on the Cloudy Nights DSO forum, 'What confirms a"confirm"?' and watch what turns up.

=Dana
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Old 10-03-2014, 05:18 PM
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Gravitationally lensed by intervening black hole?

Seriously, it can't hurt to investigate further if something seem odd. Plenty of interesting things have been found that way.
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Old 10-03-2014, 08:40 PM
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A very good question Dana. One I often ask myself poring over some faint GC. SNR Henize nebula N70 in the LMC was one I would only count as having seen when I'd been able to see it 3 times on different occasions. Some of those faint globs, I just never am sure.
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Old 10-03-2014, 09:43 PM
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madbadgalaxyman (Robert)
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Quote:
Originally Posted by Weltevreden SA View Post

So have any of you ever fooled yourself into thinking you saw a tough object that other observer reports indicate that we may be seeing what we want to?
Yes, I think the phenomenon of "averted imagination" is common enough;
.......not that I would ever accuse the "eagle-eyed globular hunter of the Karoo" of such a thing.

(Though certain other observers definitely have got bad reputations for this sort of thing.)

As I mentioned in the (really excellent) sticky on how to optimize visual deep sky observations, if I am not sure I am seeing something, then I try to convince myself that I am not seeing the object.
If an object is still stubbornly detected despite my attempts to prove that I am not seeing it, this tends to increase my confidence that I am seeing it.

Object/sky Contrast (strictly Object+Sky minus Sky) is everything in deep sky observing, so maybe your observation is not so far-fetched! Maybe you just have much better skies than the rest of us.

Also, You are so single-mindedly and totally/completely/absolutely obsessed with observing globulars and dwarf galaxies that it is quite within the bounds of possibility that you are simply expanding the boundaries of what is possible in visual deep sky observation.

In my day (I was a regular visual observer for 25 years), I also definitely detected objects that few other people or no other people could see at the time.
(e.g. when I was in my 20s, my sensitivity on faint HII regions was very definitely greater than that of most other observers.....to the degree that I used to idly boast that no nebula could escape me and my OIII filter)

I don't know if anyone has ever tested the actual relative abilities of various Deep Sky observers to detect vanishingly faint light.
I do know that this sort of testing has been tried for angular resolution....and large differences were found between various observers!
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Old 11-03-2014, 05:12 AM
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03/10/2014:

I think it’s best to just wait till next dark cycle before logging Pal 3. I broke my own rule by reporting something based on only one night’s viewing instead of three.

The thread raises an idea I’ve toyed with over the years. Planetary and lunar lovers will look for hours awaiting that one second or so of perfect seeing that reveals Jupiter’s mid-belt festoons or see Rima Birt resolve into craterlets on the Moon. Atmospheric optics go from the glass equivalent of 1/4wave to 1/8 wave for a moment and then Pfft, back to ho-hum. I wonder if the same doesn’t apply to limiting magnitude. I know I see to mag 15.5 in the 180mm and 200mm scopes because I’ve got a seasonal set of standard objects that I clipped from WikiSky and annotated the star magnitudes down to 16.5. M67 is this season’s. If it’s a really good night I’ll look at M67 awhile to determine the faintest star I can see. To gauge seeing I use doubles from 0.7” to 2.0” in the Trumpler clusters in the Carina Neb. The Pal 3 session was a mag 15.1 night, and seeing was around 1.1 arcsec.

I wonder if the moments of near-perfect clarity that planetary folks get frostbite over also work for transparency. A moment comes along when the atmospheric lenses turn briefly into a big flat with no aberration, putting sub-arcsec faintnesses into the Airy disc instead of the rings. I certainly have seen plenty of objects much fainter than the rule books allow. I like globulars so much because they can resolves into at-the-limit spangles of glory as splendid as 47 Tuc. The same happens with the mag 14 galaxies in the Centaurus cluster. During this last session I logged the very reddened (12.9 mag!!) Westerlund I cluster in Ara, three separate times a night across three nights. If ever an object required patience and perfect skies, it’s that one. (Look it up on WikiSky if you want to see what reddening can do.)

Purry as I am over Robert’s esteem for my eyes, they are still 70 years old. Dark adaptation takes an hour and a half instead of ten minutes. Oh youth, youth, where art Thou?

=Dana
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Old 14-03-2014, 06:08 AM
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Gem (Grant)
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Dark adaption takes more than 10 minutes regardless of age! While most of the adaptation can be achieve in 20 mins, full adaptation takes over an hour. Usually spoiled by a neighbour at some stage... Unless you live in a remote area. I miss doing astro in rural Zambia! Except for jumping at every noise...
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Old 14-03-2014, 06:58 AM
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Weltevreden SA (Dana)
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You got that right about sounds in the night. A slithering snake sound nearby at 3 am whilst observing near a frog pond is spine-chilling. I get dive-bombed by night raptors at least once a night, probably checking to see if my stocking hat is edible. A jackal tribe howls to high heaven once or twice a night, probably consoling each other because the kudu are just too darn tough to chew. And nothing is so unearthly as the midnight arrival of a flock of spoonbills, calling like a carillon at the far end of a tunnel. With neighbours like these, I'm glad I'm too big to eat.

Where were you in Zam? I have friends who teach in remote villages. It's still a wonderful place to live. The mozzies agree, unfortunately.

=Dana
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Old 15-03-2014, 04:09 PM
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Quote:
Originally Posted by Weltevreden SA View Post
Where were you in Zam? I have friends who teach in remote villages. It's still a wonderful place to live. The mozzies agree, unfortunately.

=Dana
Kalende Village in the Mufumbwe district in NW Province for two years plus three years in town (Ndola). Rural Zambia is great, just no electricity. Even the local Boma might lose it for 5-6 weeks at a time.
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Old 16-03-2014, 05:49 AM
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Weltevreden SA (Dana)
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Remote rural Africa is a bit light on the amenities, true enough, but it's sure a great place to learn how to star-hop. Under skies like these, who needs pricey electronics if you've got a solid alt-az and a good set of eyes?
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Old 16-03-2014, 06:56 AM
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Gem (Grant)
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Originally Posted by Weltevreden SA View Post
Remote rural Africa is a bit light on the amenities, true enough, but it's sure a great place to learn how to star-hop. Under skies like these, who needs pricey electronics if you've got a solid alt-az and a good set of eyes?
I learnt to star hop in rural NSW with my old 10" dob. While in Zambia I only had an 80mm refractor. In hindsight, I wish I had a good pair of binoculars.
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