ICEINSPACE
Moon Phase
CURRENT MOON
Waning Gibbous 91.1%
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28-06-2009, 05:04 PM
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Registered User
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Join Date: Jun 2009
Location: Jane Brook, Australia
Posts: 306
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Centaurus A
Hello,
I'm New to These Forums
My Names Nicholas, I'm 16 Years old and have been into astronomy for about 1yr and a half now, I got my first telescope at Christmas it is a NexStar 130 SLT. I still use this telescope its a great scope. But I was wondering if some of you pro astronomers can give a youngling some tips on how to view and image Cent A. I have tried a bit of astroimaging using both my EOS 300D and Neximage.
Thank you heaps in advance
nick
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28-06-2009, 05:07 PM
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Registered User
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Join Date: Jun 2009
Location: Jane Brook, Australia
Posts: 306
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btw i do know that for best imaging results i require a GM Mount where as the standard NexStar Mount is Alt-Az
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28-06-2009, 07:02 PM
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Registered User
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Join Date: Mar 2009
Location: Melbourne, Australia
Posts: 793
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Welcome to the forum Nick!
I don't know anything about imaging but there's plenty of great folk here who do, so you should be getting help very soon.
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28-06-2009, 07:02 PM
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kids+wife+scopes=happyman
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Join Date: Jun 2008
Location: sydney, australia
Posts: 4,979
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Hello pickelsrules, to IIS.
I can't help with the imaging, I'll leave that to those Gurus.
Visually, there are two tips I have:
1, learn to use 'averted vision'. Don't look directly at the object in the EP (eyepiece). The most sensitive area of your eye to light lies immediately surrounding your central vision. Our central vision is equiped for fine detail in colour, sacrifising light sensitivity. The area surrounding the central contains either more rods or cones (I can't exactly remember which) which are sensitive to 'black & white' light. In looking to the side (doesn't matter left, right, up or down, your preference) take time to allow the light to stimulate. You will be surprised at the detail that reveals itself. Omega Centuri will leap out of the EP with the scope you have.
This is a skill that you will develop with practice. With practice you will see more and more. Even when you revisit Omega Cen. over the years.
2, don't concern yourself with magnification. Most observing is done with low to medium power. You have probably already noticed how the image dims with increased power. Leave the power stuff for the planets and for speciallized DSO (deep sky object) inspections for when you want to increase contrast. I rarely use my 5mm. 80% is done with my 35 & 30mm and 19.5% with 15mm. That's me though.
Good luck and enjoy,
Mental.
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28-06-2009, 07:06 PM
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Registered User
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Join Date: Jun 2009
Location: Jane Brook, Australia
Posts: 306
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Will it pop out at me like if im viewing Orion nebula or will it be as dim as i have to use averted vision
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28-06-2009, 07:10 PM
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It's about time
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Join Date: Nov 2005
Location: Melbourne
Posts: 1,221
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As well as using averted vision, you must be in a dark place. You don't say where you are, but if you are in the suburbs with light pollution around you wont have a hope of finding it. However, if you can get to a suitable dark place, even your scope should pick it up. After all, I've seen it in just binoculars, and I've known others who have seen it naked eye, but we were all in dark places miles away from light pollution! The waxing moon wont help you either, for the next week or so.
No, it wont pop out. If its your very first galaxy you may miss it several times before you see it. It will be subtle, a faint smear of light, and much smaller than you expect.
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28-06-2009, 07:15 PM
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Registered User
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Join Date: Jun 2009
Location: Jane Brook, Australia
Posts: 306
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yer it is my first galaxy, ive tried to fidn others i just cant seem to see them can u tell me whats the best one to start with. I live in perth
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28-06-2009, 07:24 PM
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It's about time
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Join Date: Nov 2005
Location: Melbourne
Posts: 1,221
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I would try the Sombrero, M104, on the Corvus/Virgo border or M65 & M66 in Leo. It is still very important that you get away from light pollution. I can't emphasise that enough, particularly for a beginner. But now the moon is waxing you may have to wait a few weeks before trying again (unless you like to stay up late and try after the moon has set.)
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28-06-2009, 11:18 PM
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Registered User
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Join Date: Oct 2006
Location: Bright, Vic, Australia
Posts: 2,158
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All good advice Nick - you need dark skies and low magnification, and averted vision will be your friend!. I observe with smaller aperture than yours in good dark skies, and there will be hundreds if not thousands of galaxies within your reach! But practice is very important, and don't expect to see more than faint smudges when you start out.
Centaurus A can be difficult, especially because it's such a familiar object to us Southerners, with images of it all over the place. I couldn't see it at first, until I realised that the faintest of smudges I kept passing over must have been it. With more views, I began to notice that it appeared truncated on one side - this was the dark lane starting to register on my eyeballs/mind! Even now, I need the very best of skies to see the 'dim side' of the galaxy, but it is rewarding when I do.
You will find many other galaxies much easier to see than Centaurus A. NGC 253 is probably the stand-out Southern galaxy for new observers when it is around in our skies, but there are several others almost as good. As stated before, Sombrero galaxy is a good one, although very small.
If you can join a local astronomy club, you will get access to a wealth of knowledge and experience. Good luck with your viewing!
Cheers -
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29-06-2009, 04:48 AM
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Rod
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Join Date: Jun 2009
Location: Melbourne
Posts: 129
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Hi Picklesrules,
I've just taken delivery of my first scope and I've been blessed with clear skys both Saturday and Sunday nights. Actually last night was great because of the low dew factor. I had a plan to see my first galaxy through the scope so I chose the sombrero up near corvus. I was very surprised at its small size, but it was clearly visible with my 25mm. The best thing is there is a very easy roadmap available to help you get to it.
Here is one article that gives a map:
http://www.space.com/spacewatch/0905...ro-galaxy.html
Its almost as though someone decided to stick some signs for beginners up there.
Good luck!!
Rod
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29-06-2009, 07:53 AM
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star-hopper
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Join Date: Jun 2005
Location: Terranora
Posts: 4,311
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Well done Rod.
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29-06-2009, 12:08 PM
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Registered User
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Join Date: Apr 2009
Location: Brisbane Australia
Posts: 18
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I found Sombrero by using a laptop with stellarium installed, I basically zoomed in on stellarium to match the view I was seeing through the scope and edged my way to the target.
This Saturday I had no laptop (I forgot to charge it), and failed to find centaurus A, perhaps the quarter moon was too bright. (using paper maps and a red torch is a lot more fiddly that the laptop).
I had 3 or 4 different sets of maps and they all have different lines for the constellation centaurus, very annoying!
I was expecting centaurus A to be easier than sombrero.
Mike.
(8 inch dob, Brisbane suburbs)
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29-06-2009, 05:38 PM
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Rod
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Join Date: Jun 2009
Location: Melbourne
Posts: 129
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Now that brings up a question that has been bugging me for many years. Why do different maps have their own interpretation of the lines for constellations? I've seen about 15 different versions of virgo. Is there no definitive constellation lines authority?
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30-06-2009, 04:16 PM
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Registered User
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Join Date: Apr 2008
Location: Broken Hill NSW Australia
Posts: 4,104
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Hi Nicholas,
Cent A or NGC 5128 is quite easy to find.
Coming from Beta Cent or Hadar and heading northish at a PA of +332 degrees you will run into the bright magnitude 2.3 star HIP 66657 about 7 1/2 degrees from Hadar. Continue on in the same direction for just about the same distance that HIP 66657 is from Hadar and you have arrived at Omega Cent or NGC 5139.
Having arrived at Omega Cent, which is clearly naked eye, if you place it on the southern edge of the field of view of a 8 x 50 finder, then Cent A or NGC 5128 will be within the fov of the finder, pretty well due north of Omega Cent.
Although it is visible in the finder, it helps to gently rock the scope, as Cent A will be very small and dim in the finder. The gentle rocking movement of the scope will make Cent A more apparent and easier to pick from the stars in the field.
Regards
Trevor
Last edited by Quark; 30-06-2009 at 04:17 PM.
Reason: Name
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04-07-2009, 08:02 PM
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kids+wife+scopes=happyman
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Join Date: Jun 2008
Location: sydney, australia
Posts: 4,979
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Hi Rod66,
The stars forming the pattern of the constelations is not important. Some charts donot show the faintest stars, hence missing out on some component stars. What is important is the boundaries dividing them. These boundaries define the nomeclature of the component stars, objects, events occuring within, etc.
I have mentioned before how I can see less today with a 10" f/5 scope than I could 15 yrs ago with a 5" f/10 here in central Sydney. However, I can still find Cent A, but it's a struggle. Having seen it often I am familiar with the star patterns which surround it, making locating it easier. This doesn't help you find it, but it does show how familiar you can become with the sky.
M104 & M83 are also bright enough to be seen from suburbia at this time of year.
Be patient.
Most details through a scope a subtle. Learn to use your scope. Learn to star hop. Very soon you will be seeing more and more with your own eyes.
Mental.
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