Nebulae

[OzStarGazer]

Hello,

Are there any nebulae visible from our skies at the moment? I checked in Starry Night, but the label "nebulae" is greyed out at all times, which means no nebulae are visible? I thought it was a bit strange...

Thanks!

[JJDOBBER79 (Jas)]

There are many. M42 in orion is the best place to start. (The middle star in the handle of the saucepan). The other big ones are eta carinae (in carina, very close to southern cross) and tarantula (you will find this in the Lmc)
All of these are visible to the naked eye. There are also many many others visible at the moment, some more challenging than others. The ghost of Jupiter is a good planetary nebula at the moment as is the Eskimo or clown face nebula. Sorry don't know the messier or Ngc numbers for these, just google them. I also recommend star walk app if you have an iPhone or iPod. Easy to locate objects and will cost you $2.99. Have fun and good luck.

[OzStarGazer]

Thank you. I did see the M42 some time ago and actually yes, I see that if I search for it SN goes there but the Nebulae option is still greyed out. I wonder if there is something wrong with Starry Night; I might contact support. Until recently it did label nebulae, so I am not sure what happened. I can't reboot my computer right now, but if it still can't identify nebulae after rebooting I will either reinstall it or contact support.
I also saw something like a nebula around Saturn not too long ago. It was nice.
(Unfortunately I don't have an iPod or an iPhone...)

[mental4astro (Alexander)]

There's a lot to be said for a hard copy star atlas. Many of these also have descriptions of objects with different apertures. Couple this information with a computer or smart phone and you will be more productive.

Eta Carina, NGC 3372 - not just a nebula, but an entire cross section of stellar evolution. Drak pillars hide massive protostars, huge young clusters illuminate & ionise the surrounding gas, with their combined stellar wind push out this same gas and dust, producing massive 'bubbles' around the clusters. The protostars' gravity manages to keep a cloke of gas and dust around themselves that resists the erosion of these stellar winds, producing their black, skeletal like pillars. On the other end of stellar life is the massive stsr that lends its name to the nebula - Eta Carina. This star's hydrogen fuel is becoming depleted, & now the balance between its crushing gravity and its massive fusion energy pushing out is failing. It's experiencing 'shudders' & 'trembles' as precursor eruptions to its ultimate supernova explosion which could outshine the entire Milky Way. The precursor ejecta material can be seen around Eta Carina as the Homunculous Nebula. Even small apertures can spot it, its distinct orange colour, and ovoid shape. Larger apertures will show the filamentary structure it has. Eta Carina is expected to go supernova in the next 10,000 years.

Busy place, eh!

In M42, the dark wedge that cuts into its 'base' is the easiest dark pillar to see in the whole sky. A cluster of massive protostars is resisting the erosive power of the stellar wind from the Trapezium. The shape of the nebula is that of a giant bubble blown out by the massive power of the stellar wind of the Trapezium. The Trapezium itself is a small cluster made up of more than the four stars most readily seen. Good conditions & high magnification will show Trap E & F. Exceptional conditions & a bit of aperture can push things along to Trap G, H, I & J.

Take your time with nebulae. They tell mire stories than first glance will suggest.

Mental.

[barx1963 (Malcolm)]

And don't forget NGC 2070 (the Tarantula Nebula) in the LMC. This is the largest star forming region in the Local Group of Galaxies and is a spectacular sight it the moment in any size scope as it is high in the sky at around 11 or 12 at night.

I second what Alex said about hard copy atlases. No need to worry about how much charge is available, even in redlight mode most phones and tablets are still way too bright for effective observing and not much can go wrong with a chart!

What may be happening with Starry Night, and I have no idea for sure as I have never used it, is that "nebula" is not specific enough, maybe try emission nebula, reflection nebula or planetary nebula?

Malcolm

[Tony_ (Tony)]

I always recommend a site called www.messier45.com

You can search for all types of objects and it will give information including an image. (and maps).

eg. BN m<11 in orion
will list all bright nebulae in Orion with magnitude<11

BN m<10 size>2' dec<30
will list all bright nebula larger than 2' and south of dec 30n

You can also search ngc, ic, and nearly every other catalogue - even more obscure ones.

[Rob_K]

Originally Posted by OzStarGazer

Thank you. I did see the M42 some time ago and actually yes, I see that if I search for it SN goes there but the Nebulae option is still greyed out. I wonder if there is something wrong with Starry Night; I might contact support. Until recently it did label nebulae, so I am not sure what happened. I can't reboot my computer right now, but if it still can't identify nebulae after rebooting I will either reinstall it or contact support.

Unfortunately Starry Night searches don't seem to work like that. You can search for an NGC number, or the name of an object. So if you type in "taran" it will bring up Tarantula Nebula but if you type in "Nebula" it won't bring up anything as there is no name "Nebula Such&such". Typing in "NGC 2070" will also bring the Tarantula Nebula up. "Orion" will bring up Orion's Sword and several other things. Starry Night will not recognise some common names, and some of the names it does recognise might be unfamiliar!

If you want to see nebulae, tick the "Finest NGC objects" or "NGC/IC database" boxes in the Options tab, then zoom in and scroll around. You can untick all of the sub-boxes except nebulae.

With comets, searches have to be in the comet name (eg Lovejoy) - designations (eg C/2013 R1) don't work.

All the above applies to the version I use (SN Pro Version 5.0.1), others might be different!

EDIT: By the way, I'd be more than happy if someone chimed in and said I was an idiot, and that there's simple ways to adjust the search criteria in the settings!

Cheers -

[OzStarGazer]

Thank you all for the replies! I will check out those nebulae as well as the messier45 site.

Concerning SN, I was just trying the tab "Labels" and the nebulae are greyed out (I didn't specifically search for "nebula"). I am positive it worked in the past, just a few weeks ago when I bought my scope. When you "label" something in SN basically it shows all names on the screen. I don't always label everything of course because otherwise it becomes too crowded (it is a laptop, so the screen is not huge...)

Thanks again!

[OzStarGazer]

OK, I think it works now after being brave and resetting to factory defaults. I had not changed anything and it was working only recently, so I don't know what happened... Now I just have to change a few things back to have it as it was before resetting and then it should all be fine. I cannot wait to observe the nebulae you have mentioned. I just got my nebula filter the other day!
PS: I realize a nebula filter is for nebulae, but some people say they also see more stars. I didn't, maybe because it is not a large scope.
It is a Celestron filter, and it should work fine with a 5" scope, and even a 4" one, but probably only for nebulae:
http://www.celestron.com/astronomy/c...r-1-25-in.html

[barx1963 (Malcolm)]

The filter is a light pollution reduction filter that filters out the light created by common sources of LP, eg streetlights etc.
As stars usually emit light on a very broad band, they will dim stars. As it will darken the sky background the contrast with stars is improved but they mainly improve contrast for dim objects such as nebulae.

[OzStarGazer]

Thanks, yes, the filter should be fine. I hope I will be able to test it on a nebula soon (clouds permitting). I might be able to see the Clown Nebula tonight. Maybe also NGC 2264 and M42.

[OzStarGazer]

Well, I saw the Beehive Cluster (M44) pretty clearly, I think also the Christmas Tree Cluster (NGC 2264), but I could not find the Clown Nebula. Unfortunately I think it might have been hidden behind a tree. I tried to find it based on Jupiter's and Procyon's locations, but no trace of it.
This morning I saw Saturn's nebula though.
I guess it is normal that with a UHC filter objects have something like a red rim?

[ZeroID (Brent)]

Saturn does not have a nebula, it is a planet. You are possibly seeing the rings but based your your latter comment ' red rim' maybe you are seeing the affects of chromatic abberation which is the colour shift that achromatic refractors exhibit due to their design.

[OzStarGazer]

Thanks, Brent. I meant the halo around Saturn. I could also see the rings (separately and much sharper than the halo). The halo was huge all around Saturn and its rings. The contrast was even bigger with the UHC filter. The red rim only appears with the UHC filter. It is very thin and like an outline (not a complete outline though - it resembles an arc in spherical objects for example, not the complete circumference). Sometimes I also see some green with the UHC filter. I have found other people who mention this problem with UHC filters on the net (if it is a problem).
PS: I think the term "planetary nebula" had confused me a bit because I thought one could call the halo around certain planets "nebula".

[OzStarGazer]

Ok, I read that it is normal to see colours when viewing objects with a UHC filter because a nebula filter is for viewing nebulas and not other objects... The colours are apparently the effects of the multi-layer dielectric coatings which are used to create interference filters.

[barx1963 (Malcolm)]

The term Planetary nebula can be very confusing. It has nothing to do with planets. They are the atmosphere of dying stars like our sun will be in 5 billion years that has been cast off and is expanding. The best filter to use with these is an OIII as that is the light band that is emitted strongly by most PNs. A UHC filter will help with dim ones (NGC 7293 the Helix for example) but most are reasonably bright. Many are however quite small and appear as stars rather than discs, so "blinking" an OIII can help pick them out.
The "halo" around Saturn is most likely light scatter from a bright object, maybe excerbated by haze in the atmosphere or condensation on optics?

Not sure about the "clown" nebula? Do you have a catalogue number (NGC for example) for it?
As a rule it is often a good idea to use catalogue numbers followed by a popular name as some "popular" names are not well known and there are duplicates. For example the "Saucepan" refers to Orions belt and sword here is Austrlia but to the Big Dipper in the northern hemisphere (or at least it did when I was a child in the UK) and that is also known as the Plough. There are at least 2 galaxies called the Hamburger that I know of.

Actually I have just had a thought! maybe you mean the "Clown Face" nebula? That is more popularly known as the Eskimo nebula and properly as NGC 2392 (see http://en.wikipedia.org/wiki/Eskimo_Nebula )
Yes you should be able to find it if the Twins (the stars Castor and Pollux) are visible. Finding it is really easy but remember it is small!

First locate Wasat or Delta Geminorum in your finder, then move your scope about 2 degrees roughly east until you see another bright star with a dimmer companion just west of it, scan the area within 1 degree south of that star (to move south move your scope up in that part of the sky) with your main scope and you should find a "fuzzy"star with a dimmer star just north of it.
As I said it is small and you will need good seeing to tease much detail out at higher power. The central star is an easy get in my old 12".

Cheers

Malcolm

[OzStarGazer]

Thank you, Malcolm! I might buy an OIII filter too in the near future.
Yes, I agree that the term "planetary nebula" is confusing.

I think I found the Clown Face Nebula yesterday. (For some reason Starry Night omits the "Face" in its definition.) It was "just" before it disappeared behind a tree and it was very small, as you said. I was using the 25mm eyepiece by itself and didn't have time to change it because it was really just disappearing. I will try a bit earlier tonight (weather permitting). If I use the filter even if the sky is not dark yet it should be fine.

Later I looked at the sky again with the LPR filter and it was beautiful so dark, even if the stars were a bit dimmer of course.

[barx1963 (Malcolm)]

Originally Posted by OzStarGazer

I think I found the Clown Face Nebula yesterday. (For some reason Starry Night omits the "Face" in its definition.)

Another good reason to use the correct designation for objects!!

Malcolm

[barx1963 (Malcolm)]

The term "planetary nebula" originated with Herschel who discovered the first one and noted their resemblance to planets, eg round and often coloured. Of course many are not round but still come within that class of objects.

Malcolm

[OzStarGazer]

Yes, the NGC designation is better.

I had indeed heard of a "Saturn nebula". Now I know it is something else and doesn't have anything to do with the planet , but it does resemble Saturn (from a distance).

http://www.nckas.org/images/objects/ngc7009.jpg

More details and colours:
http://upload.wikimedia.org/wikipedi...009_Hubble.jpg

(Not my photos!)