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Pleaides Nebulosity

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#1 Slow Astronomer

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Posted 09 December 2012 - 03:24 PM

Can the nebulosity associated with the Pleaides be observed visually or is it only visible via AP? If it can be visually observed is the a particular filter that may help? I observe mostly under light polluted skies so I don't see it from here but I'd like to try from a real dark site.

Thanx, Dave

Dave

#2 Bill Weir

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Posted 09 December 2012 - 03:41 PM

No filter is required. This object requires dark transparent skies and clean optics. Many who claim to have observed the nebulosity have been fooled by moisture in the air.

Bill

#3 Slow Astronomer

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Posted 09 December 2012 - 04:27 PM

Thanx for the quick info Bill! :bow: I'm trying to plan a real dark site visit while they are still in the night sky.

#4 LivingNDixie

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Posted 09 December 2012 - 04:45 PM

No filter is required. This object requires dark transparent skies and clean optics. Many who claim to have observed the nebulosity have been fooled by moisture in the air.

Bill


This.

I have never seen it and I have tried several times.

#5 blb

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Posted 09 December 2012 - 05:44 PM

No filter is required. This object requires dark transparent skies and clean optics. Many who claim to have observed the nebulosity have been fooled by moisture in the air.

Bill

I have seen it about once a year from the clubs dark sky site in a yellow zone. I also agree that seeing this object requires dark transparent skies and clean optics. I have also thought that it looked like my optics were fogging up, because it resembles fogged up optics a lot, but after comparing the Pleaides with other bright stars nearby and looking at my objective lens, the only conclusion is that this is how the nebula appears. So if you think you see the nebula, check out the Hyades and other bright stars in the neighborhood, if they do not appear to look foggy, then I guess you have seen the nebula.

#6 Feidb

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Posted 09 December 2012 - 06:36 PM

I've seen the nebulosity without filters plenty of times.

I've also tried filters. As often as not, especially with the O-III, the filter actually hurt the nebulosity, cutting it down to almost nothing. Not so much with the UHC, but I've only tried it once and it enhanced the nebulosity just a tad.

#7 LivingNDixie

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Posted 09 December 2012 - 07:12 PM

I've seen the nebulosity without filters plenty of times.

I've also tried filters. As often as not, especially with the O-III, the filter actually hurt the nebulosity, cutting it down to almost nothing. Not so much with the UHC, but I've only tried it once and it enhanced the nebulosity just a tad.


Which LVAS site did you see it? I can't imagine Echo Bay or Nelson's Landing are dark enough. I have tried for it up at Cathedral Gorge, I couldn't really convince myself I was seeing it vs the glare of the stars.

#8 Feidb

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Posted 09 December 2012 - 07:58 PM

I've seen it at Redstone Picnic Area, Lee Canyon Weather station, Death Valley, Cathedral Gorge, Desert Springs Preserve, and a few other places I can't remember. All of them were dark enough. Plus I've seen it (the Merope nebula, I think it's called) at lots of other sites where I've lived. Of course, I'm using a 16-inch aperture... One home-made, the other commercial. That makes a difference.

#9 starrancher

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Posted 09 December 2012 - 08:04 PM

Pretty easy from a green / blue zone with an 8 inch . Low power wide field . Say 25x to 30x works good .

#10 Feidb

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Posted 09 December 2012 - 08:57 PM

Now that I remember, I had no idea the nebulosity existed until I completed my 16-inch f/6.4 in 1987. Before that, I had an 8-inch f/9.44 and never saw a thing except the bright blue stars so don't feel bad for not seeing anything. Of course, at the time I was using either a .965" Kellner 20mm eyepiece left over from my Sears refractor or my good old war surplus Edmund Scientific 32mm Erfle through a mirror that hadn't seen a new coating since 1968.

#11 Ira

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Posted 09 December 2012 - 09:34 PM

I have seen it easily in my 5" APO under the dark, desert skies of Israel. It doesn't look like a veil, as it appears in images. It looks more like your optics are slightly fogged. It requires excellent contrast because of this. Once you see it it becomes quite unmistakeable.

/Ira

#12 MikeBOKC

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Posted 09 December 2012 - 09:43 PM

Foggy optics describes it. I have seen it faintly but unmistakably from dark sites in my 11 inch SCT, mostly around the cluster's brightest central star.

#13 Tom Polakis

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Posted 09 December 2012 - 11:03 PM

Aperture is not as important as contrasty sky and optics. A good 6-inch should easily show the nebulosity south of Merope. On the best nights, you can see some of the paint brush stroke structure that shows up in images.

Tom

#14 BrooksObs

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Posted 09 December 2012 - 11:44 PM

While on the subject of the Pleiades nebulosity and taking the question a bit further perhaps it would be interesting to ask at this point, and possibly to the astonishment to some here, how many have been able to catch sight of the exceedingly faint nebulosity that totally envelops the entire cluster by using only the naked eye? Admittedly, it does require skies that I would guess few of us have access to these days, but there must be some other old-timers among us.

BrooksObs

#15 GlennLeDrew

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Posted 10 December 2012 - 12:47 AM

The Merope nebula, which extends far enough south to make it unambiguously not just scattered starlight, has been seen by me routinely in 10X50 binos, and is dead easy in 25X100s.

#16 David Knisely

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Posted 10 December 2012 - 01:37 AM

Can the nebulosity associated with the Pleaides be observed visually or is it only visible via AP? If it can be visually observed is the a particular filter that may help? I observe mostly under light polluted skies so I don't see it from here but I'd like to try from a real dark site.

Thanx, Dave

Dave


The nebulosity requires a good sky, but is slightly enhanced by the use of a broad-band LPR filter (Lumicon Deep-sky, Orion Skyglow, etc.). I find that with my 100mm f/6 refractor from my driveway in-town, I can't see the nebulosity in the Pleiades very often, but using my Orion Skyglow filter, it starts to become visible on most any good dark night from my home, although it is still pretty faint (requires averted vision). Outside of town at my dark sky site (ZLM 6.5), a filter isn't usually needed. Indeed, even in my 80mm f/5 refractor at low power, the nebulosity isn't all that difficult. The part that usually shows up more prominently is the area around and south of the star Merope, where a faint broad fan of diffuse light can sometimes be seen extending away from that star. The other areas of nebulosity are much harder to detect visually, although they can be imaged fairly easily in long time exposures of the cluster. In my 14 inch, I can sometimes see hints of a wispy structure to the nebula, but overall, it is more of just a diffuse glow of slightly varying brightness than anything else. Clear skies to you.

#17 timokarhula

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Posted 10 December 2012 - 05:18 AM

The nebula that stretches southward from Merope (NGC1435) is not difficult to see from dark skies once you know how it looks like. The smallest instruments that I have seen it was with a 8x50 finder and with hand-held 10x50 binoculars. It is clearly not fog in the optics since there is no "nebulosity" north of Merope and the nebula is therefore asymmetric.

/Timo Karhula

#18 Rich (RLTYS)

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Posted 10 December 2012 - 08:53 AM

Can't say I've ever seen it. :(

Rich (RLTYS)

#19 Tony Flanders

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Posted 10 December 2012 - 01:23 PM

Can the nebulosity associated with the Pleaides be observed visually


For me, the problem is my eyes. I see halos around all bright light sources, which makes it essentially impossible to see the (numerous) cases of faint nebulosity around bright stars.

I can see the southern edge of the Merope Nebula, but only if I put Merope itself outside the field of view.

You can tell if you're seeing the real thing if the nebulosity is strongest (or present only) around Merope. If it's caused by fogged optics, it will be strongest around Alcyone.

#20 Dave Mitsky

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Posted 10 December 2012 - 02:08 PM

I've observed said nebulosity a number of times from dark sites. Under excellent conditions, it's been fairly easy to see, especially the Merope Nebula (NGC 1435), through various binoculars and rich-field telescopes such as my 101mm Tele Vue refractor.

http://messier.seds....045_merope.html

http://martingermano.com/N1435.htm

Dave Mitsky

#21 JasonBurry

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Posted 10 December 2012 - 02:26 PM

I see the Merope nebula fairly regularly from my blue/green back yard. Living adjacent to a large body of water, it's very reminiscent of atmospheric haze, except as noted above, it doesn't concentrate around the brightest star in the cluster.

The Pleaides can fool an observer into thinking the skies are less transparent than they really are. Compare them to other nearby bright blue stars, and the nebula becomes more clear.

J

#22 Starman1

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Posted 10 December 2012 - 03:09 PM

The nebulosity the Pleiades sits in seems to be visible to the naked eye.
Several observers one night noted that there was a glow associated with the Pleiades that was absent in the Hyades, when looking at both with the naked eye.
So, we did a few averted-vision drawings of the shape of the glow surrounding the Pleiades, and found a good match to photographic exposures that were long enough to see most of the nebulosity (REALLY long exposures show the Pleiades is toward one end of a nebula running more than 3 degrees, but I'm only talking about the nebulosity close to the stars).
I always thought the glow from the area was a little too high to be accounted for solely by the stars.
On this night, I counted 9 Pleiads, as I usually do, and one teenager up on the mountain for his astronomy class drew a map locating about 16 stars. Oh to have his eyes!

No such glow, by the way, shows up around any group of stars other than the Pleiades. Try drawing the shape of the outer edges of the glow and you'll be surprised.

As for the Merope nebula, I recall seeing it for the first time in 1963 with a 4.25" reflector. In my 12.5", it's not as "comet-shaped", but filled with striations. Such is the advantage of aperture.

#23 JasonBurry

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Posted 10 December 2012 - 03:29 PM

Yes, I'd agree with that! I've never attempted to sketch the nebulosity, but there is never a night when the sisters don't seem bathed in haze, even naked eye.

I've seen long exposure widefield shots that show that area of the sky to be extremely "dusty", from Pleaides to Hyades and beyond, great sheets and filiments of gas and dust....

J

#24 Dave Mitsky

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Posted 10 December 2012 - 03:48 PM

Here's one of my favorite shots. It was done with a Tele Vue NP-101is and an SBIG STL-11K camera.

M45 "The Pleiades" and IC353 + IC1995 by Tony Hallas

http://apod.nasa.gov...d/ap071122.html

#25 Carol L

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Posted 10 December 2012 - 06:43 PM

So if you think you see the nebula, check out the Hyades and other bright stars in the neighborhood, if they do not appear to look foggy, then I guess you have seen the nebula.


You beat me to it Buddy! :grin:
I always tell folks to decide by comparison... that's the sure-fire test as far as i'm concerned.

Dave, thanks for the APOD link... what a beauty!! I hope none of the tinfoil-hat gang reads this,
but those lines in M45 bear a striking resemblance to really big contrails. :lol:






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