Dumb questions - version ?

[desler]

Hey all,

I'm starting to wonder about the gods conspiring against me about getting to see Venus and Jupiter, I've stayed awake all night, got up at 3.30 am and just can't get rid of those clouds!!!!!! I find it amazing how it can be crystal clear at 8.30pm est, and at 4.00am, I cant see anything but clouds.

I'v been spending my time trying to figure out star maps and a planisphere! I ahve wondered at NGC 5139, which I believe is Omega Centauri, and get ver good views, even in me overly light polluted backyard! It's listed on star explorer with a Mag 3.70. Further to the north - east is listed NGC 5128 Galaxy listed with a mag 7.0.

I've been searcing and can't see anything, even remotely, My question is, with the 8 inch GSO am i likely to be able to see a Mag 7.0 object from a light polluted area or am I looking to head to a dark sky area or simply wasting my time and move on to find something else?

Darren:eyepop:

[erick]

Darren, I'm not surprised that you are not seeing NGC 5128 with your 8" under bright Melbourne skies. I haven't. Stick with the Moon, planets, bright stars and a few brighter globulars and nebulae under such skies - that is plenty. Save the fainter objects (eg. galaxies) for darker skies. I know some persist trying to observe under such bright skies, using filters etc. Seems to me it's a struggle not worth pursuing when even half an hour's drive from Melbourne's outskirts can get you into much better skies. Particularly when you have the portability of an 8". Eric :)

[Starkler]

Ngc5128 is for comparison purposes, a large and low surface brightness object. There is another galaxy in centaurus ngc 4945 which should be much easier to spot. A couple of others worth trying would be the spindle galaxy ngc3115, and M104 sombrero galaxy.

If you take your scope to a dark sky site you can see these objects in your finderscope and the difference between suburban viewing and dark site observing has to be seen to be believed.

In short, extended objects with low surface brightness will be the hardest to see where there is light pollution.

[goober]

Quoted for emphasis :)

I had the same with M1 - Crab Nebula. I could never spot this from my backyard. Finally got a much smaller scope I could port to dark sky, and it's as easy as easy.

I have seen Centaurus A with an 8" from Melbourne, but you need transparent skies, with the object at or near the zenith. Now is probably the best time of the year to try it, is it will be at the zenith around 2am and hopefully half of Melbourne's lights are off. I saw it in binoculars from Melbourne at 1:45am on Sunday night - the skies were very clear.

[erick]

OK, Doug, I'll give it a go this weekend. Moon will have set. Weather forecast is promising. See if you spot it first, Darren! But Geoff's suggestion of looking for M104 is a good idea. Much the same time would be best - around 2am after Moon is out of the way. M104 is a nice sight, and fun to find, starting from Corvus!

[desler]

Thanks for all the tips guys.

Just need those clear skies. I am using the snow-forecast.com.au site for cloud predictions, but find them not all together accurate, yes being a prediction I know that they're not meant to perfect, but is there any other sites which give a more detailed view of cloud cover.

Daz:doh:

[MrB]

Hi Darren,
I can only just see NGC5128/Cent.A with averted vision from my backyard with a 6".
If the conditions allow, I can see 5.5mag stars direct and 6.22 averted from the back yard. I suspect Melbourne is far worse.

From a dark sky site however, I can see Cent.A naked eye(averted) with no problems and in 7x50 bin's it's great.

The first pic is of the light pollution over Melbourne:
And for comparison, in the second pic, My house is at the black cross, and the dark sky site I mentioned is roughly where the red cross is.
Both are to the same scale.

BTW, 5128 is listed as mag6.8, but its surface brightness is 13.5! Makes it a bit more difficult :(
The 6.8 is if all its light were coming from a single point, like a star, instead of over a larger area.

[Paddy]

Hey Mr B, where did you get those light pollution maps from? Very interesting!

[edwardsdj]

Hi Darren,

I used to be able to just see NGC 5128 from my backyard in Brisbane. I could easily make out the dark lane running though it with my 8" SCT.

They built a high school down the road a few years ago which is lit up like a Christmas tree at night and I've never seen it since :(

It is an easy target in a dark sky :)

Have fun,
Doug

[erick]

Patrick, check this out:-

http://www.iceinspace.com.au/index.php?id=63,404,0,0,1,0

There is a link to light pollution maps for the whole world. :thumbsup:

[MrB]

Yep, thats it, direct link is: Here (http://www.lightpollution.it/worldatlas/pages/fig9.htm).

Be aware though, while the download is only 1.2Meg, the extracted file is 280 Meg!!!
Why they didn't just provide a GIF version I don't know.....
While you're there, check their thumbnail images and compare the difference in light pollution between us Aussies and the US and Europe!
Boy have we got it good!

[Paddy]

Thanks guys. My main interest was to see that my place is in the grey, not the black - I thought it was pretty dark! But then again I can see the loom of Melbourne over 100km away. So, not perfect, but still very good.

[erick]

Don't the folks at Siding Spring state that Sydney's light pollution is now detectable from there! That's some 350km away, isn't it?

[MrB]

Spare a thought for the Perth Observatory... it's in the orange zone now :(
Time they made a move methinks.

I'm now looking at land in the central wheatbelt on the border of the grey/black(below and to the right of the red X in the Perth image above), possibly to live, but maybe just as a getaway.
Decent acerages and fair prices considering the state of the boom over here, will still have to wait a while tho...

[desler]

Hey all,

Let me premise this by saying that I've been on leave from work for the last four and a half weeks, and by renovating the bathroom during the day the wife has left me and the telescope alone at night which has seen me put in some hours in both, good to very bad seeing conditions.

What I hadn't beenable to do was manage to see Jupiter or Venus, (cloud cover) or clearly identify a galaxy (to my own satisfaction).

So thus following advice I packed up last night and headed for darker skies at Daylesford (rain) then the road to Catlemaine. I eventually found an area just past Mount Franklin, the sky looked great with the naked eye, but the wind was the kicker, blew a gale, or what felt like a gale on the side of a Mountain.

To top it off I find that one of the pivot points attached to the OTA has worked loose???? and after about an hour intermittant cloud kept annoying me.

Now some may say this was a waisted trip, not so, I learnt that it isn't as easy to navigate through a dark sky as there are just so many more objects visible to the naked eye. I also learnt that I will definately be heading away from Melbourne more in the future, however a bit more research on a good site, out of the wind is a must.

Ah well, back to work tonight, Dark clear skies to you all!:hi:

[MrB]

Hehe, good stuff. If you're driving away from the lights... you've got the bug!
Shame about the frustrations though :(
Stick with it and you will be rewarded.

[erick]

OK, I had a go tonight to see what I could get from the backyard under Melbourne light pollution. Transparency appeared good. M104 in the 12", high in the sky - easy. NGC5128 (Centaurus A that we were discussing) with the 8" scope - I could just make it out direct vision. I needed to use averted vision and movement of the scope to pick up the broad dust lane. So, I agree, it can be done. :thumbsup:

I pointed the 12" towards the Leo Triplet. M65 and M66 were faint, but visible with direct vision. The third member of the triplet, NGC 3628, I couldn't see. I wanted to try M83, but tree in the way.

That is interesting. I hadn't expected to see them that easily. Plenty of light in the sky at my place - can work without need of any redlight torch most of the time.

[desler]

Finally got them at 5.20est yesterday morning. Venus and Jupiter.

As an observation report, I'm probably not the best at describing things but Venus sat lower in the eastern sky and was (as my wife put it) ((yes I was brave enough to wake her)) the brightest object she's ever seen in the sky. As for detail, I really can't say that I had that much time to sit and stare, but I didn't really notice anything.

Higher in the sky and just slightly north, was the prize, Jupiter. Even from my light polluted back yard, it was awesome!!! I could clearly see the four moons, the more orange of the moons appears to be just off the southern edge of the planet. Jupiter itself was clear and bright and I could make out two caramel stripes running across the planet surface.

Saturday night, I attended a ASV, How to use your telescope evening and had a brilliant time, learnt heaps, and had a great time in excellent company. From a park in southern Melbourne, saw omega centauri, 47 Tucana, Ngc 2516, the jewel box and pleiades. Spent a fair bit of the evening getting the hang of averted vision. I've read about alot of people here doing it, but I've always found personalised instruction easier.

After getting home at a very reasonable hour, I just couldn't stand the idea of going to bed when there were clear skies!!!!!!!!!!!!!so staright out into the backyard and put a few of the things I'd learnt during the evening into practice.

After, 2.15am or so, with the moon disapearing in the west, Scorpius was visible in the east and I managed to see M4 straight view, and M80 with averted vision. Then M6 and M7 and a little later, Jupiter again.

All in all, a great weekend of viewing.

Darren:whistle:

[erick]

Darren, you're "cookin' with gas"! Sounds good to me! :thumbsup:

[goober]

Good stuff, guys. Erick, sounds like we were looking at the same things at the same time. I'm about to post a report.