Observation Notes - 18th December 2015

[MarsG76]

18th December 2015

Equipment: NexStar 8SE

Time: 01:00 - 03:30 AEDT (14:00-16:30UT)

When I arrived home from work I noticed that the sky was crystal clear so I couldn't let this opportunity by without doing two things, 1 to replace the neodymium filter in the 80mm frac and continue to take more subs of Barnard 33... This time 20 minute ISO800 subs through the HBeta filter. I figure that if the HBeta filter helps to find the Horsehead nebula visually, surely 20 minutes subs would show it up as bright as HAlpha.

The second thing I had to do is observe the objects I looked at last outing when there was a little bit of haze around for a comparison in what's visible.

I started with 47Tucana (NGC104). In the 40mm eyepiece it already before full dark adapted eyes started to show some granulation of stars with in the core, as well as a lot of stars becoming more sparse further from the core. The 11mm eyepiece showed a lot of individual stars all the way through the object. The best view came through the 25mm Celestron E-Lux eyepiece, but that's only because the sprinkling of stars was almost to the edge of the FOV, and seeing the whole cluster in one view looked awesome. The view was no brighter than in the 11mm Nagler, just that the whole object was visible. The globular brightness was about the same through all 3 eyepieces used.

On that note, I was expecting the globular cluster to be brighter than it was after reading others descriptions, but it was not disappointing at all, completely the opposite, it was a great view that I spend a fair bit of time on looking at it through various eyepieces and filters. The best way to view the globular was with no filters as even the LPR filter cuts out enough light to take away crucial detail.

NGC362: After looking at 47Tuc for a while, I wanted to see if any of the other two close objects are visible, and to compare them to 47Tuc. NGC362 was a lot smaller and fainter than 47Tuc. There was a sprinkling of external stars visible. This is definitely the globular cluster I was looking at when I was looking for 47Tuc on the first night.

After NGC365 I slewed toward NGC265 but nothing was visible but a couple of stars in the area.

Carina Nebula: NGC3372 was a amazing view like always, this nebula just doesn't disappoint. The UHC filter reveals a lot of obvious and ghostly nebulosity with a lot of detail and structure within. This nebula is one that benefits in being observed in various magnifications, 40mm, 25mm and 11mm with and without the F6.3FR. The LPR & CLR filters show more nebulosity than without any filters but not as much as the UHC. The benefit of the CLR filter in particular is that it retains the star colors as well as enhances the nebula, not as much as UHC but more that LPR and bare. The view not only had star colors but the nebulosity was noticeably a gray ghostly color as opposed to a deep blue/gray hue across the whole view through the UHC. LPR has a similar view but the CLR definitely has the contrast which makes it look better. The OIII filter showed fainter nebulosity and looked like it was revealing different detail in the structure.

NGC3766: After observing the Carina Nebula, I slewed to NGC3766 for a comparison to the previous nights view. It is quite a large dense star field making a oval shape out of the stars. There were a few orangeish stars in the cluster, but most of the stars were white. The cluster resembled a swarm of fireflies.

Orion Nebula: The Orion Nebula showed a distinct shape to the nebulosity as expected. The fishes mouth was obvious but not as clear cut as I have seen in the past. The UHC filter really brings out the nebulosity in M42 and M43. At times through the 25mm eyepiece the upper "loop" adjacent to the fishes mouth and M43, but the "mustache" shape of the nebula stands out with quite a bit of detail showing through.

The OIII filter showed the Orion Nebula a bit fainter but in turn it seemed like there were either different details visible or the details were the same as through the UHC filter only with greater contrast.

The 25mm eyepiece showed an awesome view of M42.

The trapezium of stars at the core were distinctly clear and I decided concentrate to see if I can see any more stars rather than just the 4 famous ones and compare to the last observation nights view. Looking through the 11mm Nagler I quite easily picked out a star about equal distance and a bit out between the two closest stars and in and there was a star coming in and out of view on the other side of the trapezium, very close to the brightest out of the four. Looked like it was in a different spot to last time???!!?

Running Man nebula was starting to be visible, but it was nothing more than a haze around the brightest stars and within the general area but no hint of the running an shape.

Barnard33: The Horsehead and Flame nebulae were still undetectable through UHC or bare.

The Hbeta filter was used for exposing Barnard33. Looking at the exposures so far, the subs show very little of the Horsehead nebula compared to the HAlpha exposures. I don't understand how does this filter supposed to help show Horsehead when viewing through the eyepiece if 20 minute exposures shows less than a HAlpha 5 minute exposure???

Tarantula Nebula: right from the time I framed up the Tarantula Nebula it was obvious that the view was noticeably more detailed and visible than the last time I looked at it through the slight haze. The best view was using the 25mm eyepiece and through the Lumicon UHC filter. The central part of the nebula was noticeably brighter with a star just off center in it, bright enough not to be cut out by the UHC filter. There were fainter but nonetheless obvious visible loops extending from the brighter nebula core that made the tarantula or cartoon flower shape. In the 25mm eyepiece the nebula fit in nicely, not too small but also not edge to edge of the FOV and was comfortable to observe. The CLR and LPR filters also showed the outer nebulous loops with the benefit of a more natural gray color with star brightness standing out more than through the UHC. The UHC showed most easily visible outer nebulous loops there the CLR was next best with natural colors and the LPR had less contrast. The OIII filter showed faint loops but I preferred the views through the UHC and CLR filters using the 25mm eyepiece. Nebulosity is visible with no filters but filters do help a lot.

Jewel Box: The Jewel Box star cluster looks best with no filters through 25mm and 11mm eyepieces. There are perhaps over two hundred stars visible in the star cluster with various colors to the stars, with the orange star standing out. Very nice view through the eyepiece, one of the objects with a view that no photograph can do it justice compared seeing it through a eyepiece.

Omega Cluster: Toward the end of my observing session I decided to checkout if the Omega Cluster was visible, it would be good to compare it to 47Tuc as Omega Cen is the brightest and biggest Globular cluster in the sky.

Luckily it was above the horizon and toward the brightest sky glow area from the CBD, nonetheless the view was still clear and full of detail.

Omega Cluster is bigger than 47Tucana and it definitely has a bigger core with dense stars clustered together, even the outer edges have a lot more stars than 47Tuc. The overall brightness of Omega Cen was about the same as 47Tuc but it was low in the south eastern sky where there was a lot of sky glow from the CBD, so the view will most likely be a considerable amount clearer with the added contrast when the Globular cluster is higher in the southern sky away from the city sky glow, definitely a object to be visited in a month or two.

During the observation through the 40mm eyepiece there was a meteorite that streaked top-down through the FOV at 01:06 AEDT.

Best view of this globular was through the 25mm eyepiece as the glob fit into the FOV but the 11mm made it easier to see the individual star granulation in the core.

Crab Nebula: M1 was low, about 20 degrees above the north-western sky and was visible nothing more as a smudge barely visible through the Lumicon UHC filter, and was harder to spot without the filter, the only way I spotted it was when I tapped the eyepiece to introduce some vibration and the eye picked up the contrast due to the movement with no filters. The crab was not visible at all when using the OIII, LPR or Orbinar CLR filters.

Alpha Centauri: As a test and comparison to the view I remember I had of Rigel Kent, I framed up on Alpha Centauri which was just barely coming above my pergola, I actually had to wait about 10 minutes for it to completely clear the obstruction, so it was low in the sky. The double star was barely resolvable, it was more like a fuzzy elongated star. After experimenting with various combinations of eyepieces and filters I had to use the 11mm eyepiece, 185X, and the 15% ND filter to resolve it as a double star. After the disappointing view compared to a 60mm refractor!!!, I thought that was because of it low altitude. I decided to have a look at Acrux and Canopus which were both much higher in the sky.

Acrux was much easily resolvable with the 11mm eyepiece, it showed the two distinct stars close together as well as the third a bit further out to the left and was showing a hint of diffraction rings, but it was still fuzzy/soft looking.

Canopus showed tiny solid star with diffraction rings, nearly how I remember Alpha Centauri through the 60mm Tasco... But I remember it to be much sharper through the Tasco, perhaps refractors better for stars or Alpha Centauri is too low in the atmosphere and my Tasco views were at the highest point... Or a combo of both? The only way I can work that out is to use both my 80mm and the 8SE and compare views when I'm not imaging with one scope during a observing session.

25mm Celestron eyepiece is very good for mid ranger magnification, seemed better than 40mm at a lot of instances and it's starting to look like between the 25mm and 11mm TV all deep sky observation can be done. Even when looking at Carina using the f6.3FR. The 40mm magnified less and showed perhaps more of the nebula, but the 25mm had a wider FOV, so almost showed as much, just with greater magnification and more detail, especially through CLR or UHC filter. Overall it gave a more pleasing view, especially through the CLR filter that retained the orange star color and grayish nebulosity hue, instead of like through the UHC, which showed a lot more contrast and detail in the nebulosity but made the view deep blue monotoned. Hopefully the 31mm TV will be even better.

Toward the end of the observing session when I looked up at the sky with night adapted eyes, the sky was very still and clear but also very bright and actually had a blue hue to it. This is when I realized that I don't have as dark of a sky as I though I had, yes when my eyes are not night adapted the sky looks black and still on a clear night but with night adaption the skyglow is very prominent. What I really need to do is pack my gear and head off to a dark sky location, same place I went to a while back where I actually saw structure in the triffid nebula, where here at best I see a faint fuzz.

No doubt the skyglow limits to how far my dark adaption will become as well as what the faintest objects I will be able to see, that includes the Horsehead nebula and would explain my lack of success.

So far the OIII filter did not show me any more detail or better view compared to the UHC filter. I don't think that the OIII showed anything more other than the same detail at a greater contrast that can give the illusion of different detail.

Another point is that all brightest stars in the view are fuzzy, as if they can not be focused properly. Looks like a collimation issue but on looking at unfocused stars the obstruction shadow seems to be dead center. This needs to be investigated and is definitely the cause of fuzzy bright stars and softish look to mid brightness stars in the eyepieces. Worst effect is on bright stars tho. Corrector plate and mirror are clean so that is not the cause of it.

MG

[michael.h.f.wilkinson]

Great report of superb session! Some stunning objects there that I have only ever seen through binoculars

[MarsG76]

Yes it was a awesome observing night... now I'm planning on going to a totally dark site during the next new moon... hopefully we will have a clear sky...

[estwing]

Great read of great night! Lovely list there..well done...

[Scott]

Yes it was a awesome observing night... now I'm planning on going to a totally dark site during the next new moon... hopefully we will have a clear sky...

Very interesting read mate (you'll give us imagers a bad name ). Where abouts is your dark sky and what suberb do you live? I'm origionally from nr sutherland myself

[MarsG76]

Very interesting read mate (you'll give us imagers a bad name ). Where abouts is your dark sky and what suberb do you live? I'm origionally from nr sutherland myself

I spent most of my time imaging rather than observing until recently, I simply thought that perhaps from my location I wont see much. But boy was I wrong and I was missing out... I certainly do not see anywhere near as much detail or clarity as I do from the mountains but I still have had some awesome views.

Both activities have their benefits, with photos you see the colors and way WAY more detail in the objects than looking through the eyepiece, as I'm sure you know, but than there is something about seeing it in real life that photos can not match... especially from a dark location. I remember that the time I went to a flat area quite high up half way between Sydney and Wollongong. The other place is Kangaroo valley... if you don't have people with bright lights around the area has virtually zero light pollution.

[Scott]

I spent most of my time imaging rather than observing until recently, I simply thought that perhaps from my location I wont see much. But boy was I wrong and I was missing out... I certainly do not see anywhere near as much detail or clarity as I do from the mountains but I still have had some awesome views.

Both activities have their benefits, with photos you see the colors and way WAY more detail in the objects than looking through the eyepiece, as I'm sure you know, but than there is something about seeing it in real life that photos can not match... especially from a dark location. I remember that the time I went to a flat area quite high up half way between Sydney and Wollongong. The other place is Kangaroo valley... if you don't have people with bright lights around the area has virtually zero light pollution.

I think the area between Sydney and The Gong you speak of is maddens plains (two golf courses). It is quite dark if you can find somewhere thats not hit with car lights from the F6. Kangaroo valley is loads better imho. I've got an uncle with a farm in the Riverina (Temora) and it;s so dark that the milkyway creates it's own lp . I don't get home often now, but when I do, I always head down there. either that or a mates farm outside Mudgee.

I do agree that visual ads something that imaging can't catch. I've a few mates with bigdobs and I always enjoy when I get a chance to look through them

[MarsG76]

I think the area between Sydney and The Gong you speak of is maddens plains (two golf courses). It is quite dark if you can find somewhere thats not hit with car lights from the F6. Kangaroo valley is loads better imho. I've got an uncle with a farm in the Riverina (Temora) and it;s so dark that the milkyway creates it's own lp . I don't get home often now, but when I do, I always head down there. either that or a mates farm outside Mudgee.

I do agree that visual ads something that imaging can't catch. I've a few mates with bigdobs and I always enjoy when I get a chance to look through them

Yeah, it is Maddens Plains... you know the area??... I did find a sneaky spot where I can setup and it away from lights of all sorts, the road or houses, all that's visible is a bit of a glow on the horizon north and south from Wollongong and Sydney, but its much better than back yard. I have never been hit by lights from F6 there either.

What size & type scope are you using for observation?

[Scott]

My own newt is only an 8" but Steve (Swamp Thing on here) has a 20" and Calv (Estwing) has a tiny 18" (he'll love that ). There are others too like faulksy.

I know Maddens Plains well. I grew up in Loftus and when married moved to the gong. There used to be a track just past boomerang golfcourse (on the east) that led to an open bit of ground. Don't know if they've blocked it off or not now with those mounds of dirt they use.

[MarsG76]

I can imagine what would be seen through a 18 or 20" scope.... even my 8" SCT gives me wow moments.... and that's tiny in comparison.

There is a flat bit on the western side that's not too far from the golf course. It's a large flat bit or ground surrounded by trees blocking all light from cars going past.

[estwing]

kangaroo valley...boomerang golf course...your making these names up!....Scott please stop tell us about the milky way giving off its own LP....!

[estwing]

 tiny 18"......? stay tuned

[MarsG76]

The names are very real, although kangaroo valley should be renamed to Wombat Valley... Much more wombats than Roos...

Your 18" seems tiny compared to my 200mm... I mean 200 is bigger than 18.. ;-) ha ha

[estwing]

I find the same at dark sky mate, the detail of objects when observing are truly wonderful.....have a read of this for a chuckle..http://stargazerslounge.com/topic/228371-the-night-the-terminagler-was-terminated/?hl=terminagler....terminated

[swamp thing]

Nice report.

We keep telling the flaming galah to get rid of all that imaging junk and buy a proper scope.

[laudropb]

Very nice report of a super observation session. You certainly have got me green with envy.

[Piero]

Wow! Really nice writing up of a wonderful night! Thanks for sharing your comments on the beauties of the southern hemisphere! Very appreciated!

[neural]

Wonderful report, thanks for sharing it. I saw some of the objects when we were in NZ in November, though only in binoculars and sadly not Alpha Cen.

Sounds like you bagged the E and F stars of the Trapezium - I've been doing my homework on these, hoping to catch them in the next few weeks.

[MarsG76]

Wonderful report, thanks for sharing it. I saw some of the objects when we were in NZ in November, though only in binoculars and sadly not Alpha Cen.

Sounds like you bagged the E and F stars of the Trapezium - I've been doing my homework on these, hoping to catch them in the next few weeks.

Definitely bagged E... As with the F, I might have but it was quite difficult to split... I would like to have another crack at it from a dark location.... Stay tuned.