Looking for M83

[Scooter]

Hi Ya Folks,

OK so I am up last night and still have yet to see a galaxy in the 12" dob so as I wanted a look at Saturn at about 1am I reckon M83 should be the target.

It looks great (the photos) so I start the hunt in earnest.......

....and keep looking....

...and looking. Nada - Zippo - naught!!!!

Maybe spent an hour trying to fing the damn thing without luck. Now I had Stellarium on the PC in side (with lights off inside to try and keep dark adaption) and I am back and forth etc. Now I reckon I was looking in the right place (or places ) but I got nothing.

Should I have been able to find it easily last night? What sort of eye peice should I be using? I was mostly using the finderscope and then with either the 32 or 25mm.

Bit disappointed so next time I will have to set the lappy up outside and track from damn star to star

Whats the best way to tell what I could/should be able to see (go off magnitude etc.)?

TIA

[jjjnettie (Jeanette)]

I reckon you should go for M104 first, The Sombrero Galaxy. It's an awesome sight in a 12". The dust cloud that cuts right through it, and the dome of light that glows out of the heart of the galaxy, fantastic.
It's easy to find as there are two large bright asterisms ( Jaws and Stargate ) that almost point right at it.
Here is a step by step guide to finding it.
http://www.backyard-astro.com/deepsky/top100/15.html

[Scooter]

You know Jeanette I have actually tried previously for Sombrero - will give you a guess how I went ......

..well actually maybe it was a faint smudge so at least I vaguely (maybe??) saw something

Just trying to get a handle on city skies vs dark skies (and you have dark skies yeah which explains why Sombrero looks so good for you?). Thanks for the link as they deal with this so I will have a look and see what they say and check out the 20(???) of the top 100.

Early days

[GrahamL]

hi scooter


hope this helps its pretty rough
look for this very distinctive pattern of stars at the northern end of centaurus .I've omitted all others .. make a triangle using the red point as its apex theres no star there it just a point in the sky.

Spot on that red dot theres a faint spiral galaxy..m83 itself is not far to the
east ( i think its east ? ) and should show up easily if you pan across this piece of sky and your skys are dark enough.

[Karlsson]

hi Scooter,

If you were observing from your home in Bris, at 01:00 M83 was at about 48° altitude... and from what I can see you are in in a rather light polluted area there, which makes finding a low-surface brightness object like M83 not so easy, not even in a 12" scope...

While you should be able to see its bright core now following Graham's map, I would suggest you wait until it gets a bit higher up in the sky, say 70° or higher - either between 3 and 4 AM, or from April onwards in the evening

[SkySearcher (Daniel)]

Hi Scooter

It took me several nights of hunting with my 12" to find this one as well. Which puzzled me initially as it is supposed to be fairly easy. However, It wasn't till I ventured out to a darker site that it suddenly popped out of the sky in my field. I realized that I was looking in the right place the whole time but just couldn't see it.

My advice, drive to a darker site, use the eyepieces you have been and you will have no probs.

[ausastronomer (John Bambury)]

Originally Posted by SkySearcher

Hi Scooter

It took me several nights of hunting with my 12" to find this one as well. Which puzzled me initially as it is supposed to be fairly easy. However, It wasn't till I ventured out to a darker site that it suddenly popped out of the sky in my field. I realized that I was looking in the right place the whole time but just couldn't see it.

My advice, drive to a darker site, use the eyepieces you have been and you will have no probs.

Therein are the answers to you problems.

I cannot stress enough, how important dark skies are to observing dim low surface brightness targets. Turning the lights out inside the house doesn't make a suburban or urban location "DARK". It is also worth pointing out that non astronomers and new astronomers have a different perception of "DARK" skies to hardened astronomers. To some 5 mile out of the city is dark. Not so.

Cheers,
John B

[Karlsson]

Originally Posted by ausastronomer

I cannot stress enough, how important dark skies are to observing dim low surface brightness targets. Turning the lights out inside the house doesn't make a suburban or urban location "DARK". It is also worth pointing out that non astronomers and new astronomers have a different perception of "DARK" skies to hardened astronomers. To some 5 mile out of the city is dark. Not so.

Cheers,
John B

Could not agree more - I believe new astronomers who live in the city (and that's most of them) owe it to themselves to head into the sticks at least once, so that they are aware of the difference between 'dark-ish' and really dark. Even if you reckon taking your scope is too cumbersome, just a pair of binos will do: under a dark sky your binos may reveal more than your scope in your backyard...

In order to look for dark places this work by Kal and Erick may be of help:
http://www.iceinspace.com.au/index.p...63,404,0,0,1,0
Believe me - it's worth the trip. You won't believe your eyes

[Scooter]

Thanks for all the replies and the links etc. folks Heaps to the astronomy lark

Damn the big city lights of Brisvegas . I guess the problem is going to be knowing what objects are just not going to be worth chasing due to the light polution hence my original comment regarding magnitude. Its it fair to say if I can't see something of mag X then don't bother looking for anything less or equal? Also what role does seeing play (should I be working out what the seeing is first and then if it is x I could target these objects vs y only bother with these?

Thanks for the personal clarification Daniel - as above that was what i was trying to establish. Guess I really need to see how bad things are from this location )and as the sky is fairly barren to the naked eye I guess probably not good )

Hey karlsson at the moment early starts haven't been an option so far (I am not a morning person) and I know higher = better so I am targeting with that in mind but last nights main target was to Check saturn out at it highest point so the search for M83 was killing time as it were.

Plan is definatley at some stage to go bush to see what the scope can do in better conditions

Hey John, wasn't trying to make it dark just dark adapt my eyes to be able to best see with the given conditions. I mentioned it in another thread but I spent some months backpacking in South America and when crossing from Bolivia into Chile across the altiplano you are at 4K+ in altitude hundreds of K's from anything so I know what truely great skies look like (I think it would be safe to say that no location in Oz could compare).

I think the best course for me is gonna be joing a club and then getting out on a dark sky night/s

As I said still early days

[Terry B]

It is much easier to use a finder chart at the scope rather than trying to use a relatively bright computer outside. If you can print a few charts- one with about 90deg width as a naked eye finder and then print a more magnified chart with the object you want to see and hopefully a bright star on the chart that you can identify from your other chart. I tended to make my charts 8deg across and printed them reversed like the image in the eyepiece. This will depend on the type of scope.
You can then star hop when sitting at the scope with the chart and a dim red light.
Charts can be printed from any planetarium software and some are free like CDC.

[Karlsson]

Originally Posted by Scooter

I guess the problem is going to be knowing what objects are just not going to be worth chasing due to the light polution hence my original comment regarding magnitude. Its it fair to say if I can't see something of mag X then don't bother looking for anything less or equal? Also what role does seeing play (should I be working out what the seeing is first and then if it is x I could target these objects vs y only bother with these?

CdC, as mentioned by Terry, gives surface brightness for extended objects (M83:12.8). While you were looking in the right place for M83 I'm sure you must have seen stars fainter than M83's mag of 7.6 - but the light M83 emits is spread out over a larger area than a star's pinprick. M33 is an infamous example: mag 5.7, surface brightness 14.2. In Coonabarabran I can see it with my naked eye - not even trying... but here in Sydney my 8" has trouble finding it, unless there is Absolutely No Cloud (for whomever can remember those days.)

Seeing does not so much decide whether or not we can see some object, but rather how much detail we can discern - or in simple terms, how sharp things are. Whilst darkness does not change much over time, seeing may vary on a scale of seconds (provided your mirror is at thermal equilibrium), so patience is often rewarded.

There is no hard and fast formula to decide what objects to try for under any given set of conditions - even after many years I do a lot of trial and a lot of error, too. The surprises are the best, though!

I cannot judge whether Australian skies can compare to the altiplano - but one thing many Australians underestimate is how easily accessible our dark skies are - and how much of it there still is.

[Paddy (Patrick)]

The other thing to remember when looking at deep sky objects, especially galaxies, is not to look directly at them. When you look directly at something, you use a part of your retina which has only cone type photoreceptors which need high light levels and which code for colour. The more sensitive rod type photoreceptors are distributed away from the fovea (the centre of your visual filed). They don't encode colour, so you will only see in shades of grey. So to see galaxies, point your scope at where you think they will be, but rove your eyes around the field and pay attention to what may pop up away from the centre of your gaze. You may find that if you look directly at a galaxy, it simply disappears (even fairly bright ones).

Of course dark skies are of great importance - I wouldn't be expecting too much in an urban environment. But even living in a perfect spot for dark skies, if I look directly at a galaxy or planetary nebula, it will disappear.

Good luck

[ausastronomer (John Bambury)]

Hi Scooter,

Patrick's comments re averted version are something to keep in mind when chasing dim targets like galaxies. That having been said the two galaxies you are chasing in this case (M83 and M104) are very bright galaxies compared to most other galaxies. From dark skies you will see them very easily with direct vision in a 12" scope at low power. They are both in fact easily visible in my 10X42 binoculars from dark skies.

Cheers,
John B