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View Full Version here: : Got it! NGC 3918


erick
11-02-2008, 05:59 PM
OK, I know it's not a particularly challenging target, but I was very happy to locate it after a few previous unsuccessful attempts! :thumbsup:

After the last three occasions I've been out with scope were 1) mostly showing visitors the sights, 2) clouded out at night, 3) clouded out during the day (eclipse); I finally had a good evening Sun 10th Feb.

Headed for my not-so-darksky, sort-of-close to home site, for a few hours. Ended up spending too long and heading to work with too little sleep! :zzz2: Took what is now my grab (and pack and grab more and pack some more etc :D) and go scope - the 8".

Clouds stayed away. Wind settled down to a non-irritating gentle breeze then died after 11pm. Cool - I nearly put my scarf on! It was mitten weather (Just checked the reports and it was probably down below 6 overnight there). Seeing - well I'm still not much good at estimating but the stars were dancing happily just in and out of focus and I couldn't clearly see the E and F stars in the M42 Trapezium. Not so good, I think.

Quick summary of the evening targets - mostly the favourites, as the whim took me:-

Two day old crescent Moon, M42, Tarantula and Eta Carina Nebulae (experimenting with nebula filters), M1 (filters didn't help this target at all).

Open star clusters from Crux, Centaurus and Carina.

Globular clusters in the area, Omega Centauri, 47 Tuc, NGC 362, NGC 2808. I think I saw, for the first time, a globular or two in the SMC? I'll have to come back to these later.

I located and bid final farewell to 8P/Tuttle. Don't think I'll look for it again.

Galaxies - Couldn't pull NGC 253 out of the Melbourne-bright western sky. But NGC 5128, M104, the Leo Triplet were all available for the taking.

Planets - Mars, featureless orange blob for me. Saturn later at night - nice, three moons visible to me.

Back to that nice double star x Velorum. That sure is nice and seems to be placed in a dark bit of sky, so they do stand out. Practiced finding the double in my 12x60s - easy.

Now to the challenge I had set myself - the Blue Planetary, NGC 3918 - in Centaurus. I had tried a few previous times to star hop to find it, but got lost. I think I expected it to be more distinctive to the newbie eye, but it's not - until you find it! So this time I had Stellarium running beside me to guide me, used my inverting adapter with 32mm TV plossl to give me a view I could correlate to the screen, and away I went from delta Crucis. Taking it steadily, I got there. Distinct colour and non-pinpoint object. Yep that's surely it. Pushed up the magnification to see the angular size, compared to adjacent stars. An aqua colour, it seemed to me.

Today I went looking for a picture of it in its local starfield to be absolutely sure. It seems one Scott Adler has a photo of NGC 3918 and adjacent stars here:-

http://www.blackskies.org/images15a.htm

Yes, that's it, that is what I saw, many thanks Scott!

Happily packed up around 12:30am. A hint of dew starting to form on the scope. Laptop battery had died, didn't bother swapping to the spare!

The future. Well, to get serious with the 12" and, apart from also getting serious with Glen's 95 DSO list, I want to locate and observe VY Canis Majoris - just to say I've see the largest known star (so far!). It looks like a challenging starhop to a non-descript 9.5 apparent mag star.

You know what I like about this hobby? You can see with your own eyes what it is all about. Most other things, you have to rely on others, or photos, videos etc. For this hobby, just wait until the object is above you in clear skies at night and look at it yourself, with perhaps no more that a bit of glass between you and it! I think that is exciting and a real feeling of achievement! :clap:

Eric :)

goober
12-02-2008, 02:30 PM
Nice report, Eric. I also love that little tingle of pleasure when you track something down and can see it naked eye.

Question time :)

What is an "inverting adapter"? Is it like an Amici prism for getting a right side up view through the eyepiece? I struggle a bit star hopping without a finderscope, but I'm trying to train myself to do the L/R flipping with my brain.

What is "Glen's 95 DSO list"?

erick
12-02-2008, 03:18 PM
Here:- http://www.iceinspace.com.au/forum/showthread.php?t=25920

Real name of mine:- "Vixen Erect Image Adapter"

To update, I sure wouldn't use it for anything other than finding the object of interest, then get it out of the train. I was too busy starhopping to check carefully, but it must be constricting the FOV - I certainly sensed that I was looking down a long pipe, which I am! One day I'll compare more carefully. Also I must try it for it's main intended purpose - terrestrial viewing.

I'm getting the feeling that using it, then not using it, will just confuse my brain further (is it possible?), but it is handy on those long starhops through starfields which have few good signposts!

Edit: I should have said - it works for a reflector, not a refractor (or the appropriate combination of lenses and surfaces that is equivalent to a reflector, I guess.) With a refractor, I expect you'll have a right way up, but mirror image.




Here:- http://www.iceinspace.com.au/forum/showthread.php?t=18551

From your reports so far, I think you are well beyond this list. I'm only a third of the way through.

§AB
12-02-2008, 04:11 PM
That's a quality write up Erick, thanks for posting :) NGC 3918 is one of my favorite objects, just love its apparent perfect shape and aqua blue colour. My mum was quite intrigued by it aswell.

Hmm I'm surprised NGC 253 is still around, thought it was gone long ago!

erick
12-02-2008, 04:27 PM
Should be around 30 deg elevation around 9:30pm from Melbourne.

goober
12-02-2008, 08:03 PM
Unless it's brighter than mag. 2 anything that low in the west is gone for me :)

Gargoyle_Steve
18-02-2008, 01:23 AM
Eric I'm glad to hear you conquered the star hop to the Blue Planetary. :thumbsup:
I have some personal history with that object, and I know how frustrating / satisfying an object it can be to search for.

When I started out in practical stargazing (near 2 years ago) I pretty much knew only Crux & Orion by sight, so I very slowly learned to star hop around from those known markers.

First thing I learned to do was star hop to Omega Centauri - until I realised it was a naked eye object anyway, but I'd been steadfastly doing it the hard way by looking only through the scope! :lol:

Anyway ... shortly thereafter I heard about this "Blue Planetary", and as it was right in "my" neck of the woods decided it had to be done! I had my 10" dob back then, which was still plenty of aperture to find it, and yet I failed dismally on the first 3 (?) attempts!

I remember the night I first found it, I was so pleased I just didn't want to let it slip out of my field of view so I studied it for ages. :rolleyes:

I made sure I revisited it during each subsequent observing session, and yet even though I knew where to find it, and what to expect in terms of size and apearance, there were still occasions where it eluded me!

All I can say is that I always look for it manually first, and still get a faint tingle of satisfaction from finding it - but it's good to know the Argo Navis is always there as a backup - just in case!

;)

PhilW
18-02-2008, 11:18 AM
Erick, now you've hopped to 3918, you should be able to hop down a bit to 5189 in Musca. It is a fascinating visual contrast, being highly disturbed. It should be easy in your 12". Also responds well to a nebula filter.

Phil

erick
18-02-2008, 11:57 AM
OK, I'm on it! I've just found a description of it that runs to 12 pages off my printer!!! I've checked the image - be interesting to see what I can see.

I have worked around the globulars in Musca previously.

In fact, this morning at 5:25 before I jumped in the car to head to the gym/work, I stopped in the front yard, found a spot shaded from the streetlight and marvelled at the sky. I know the seeing has been up and down and dust is building up, but it was a beautiful sight. Crux high overhead, Jupiter and Venus blazing from the eastern sky. The orange glow of Arcturus in the North - lovely. Omega Centauri popping out readily on slightly averted vision. And I particularly picked out Musca, easily.

goober
18-02-2008, 12:16 PM
I like Musca - nice and distinctive. Musca to be quite useful for getting to Apus and Chameleon too.