Got my 4" dob - Anything interesting to see?

fauxpas (Tony) · #1 19-09-2012, 09:16 PM

Got my 4" tabletop beginner's dob... Lined up the viewfinder on a yellow sparkling star I believe was antares. Checked the alignment with a few other stars and it's lined up 100%...

I wanna see if I can view saturn, jupiter and see what the moon looks like but they're all gone by the time the light fades... I imagine I'll get limited views of the planets through the 4" but hope it tickles my interest enough to get a bigger one...

Anything else interesting to check out at this time?

drylander (Peter) · #2 19-09-2012, 10:37 PM

I started with a 4" Newt and loved the moons of jupiter. I also have been moon watching and am amazed at what can be identified. Just give it a good work over and then when its easy to find planets etc invest in the next stage.
Pete

omegacrux (David) · #3 19-09-2012, 10:49 PM

The jewel box near crux is always a good look
Actually all around the southern cross is just full of things Omega cent , Eta car or you can see if you can split the pointers to the cross that's a good test

David

Varangian (John) · #4 19-09-2012, 11:41 PM

Jupiter would be a nice target in the western sky if you could get up at 5am

mental4astro (Alexander) · #5 20-09-2012, 07:12 AM

Hi Tony,

The Moon sets a little later every night during its phase. The only thing is while it is up it overpowers the much fainter deep sky objects. At this early phase, it is not so strong.

You can start scanning around the tail of Scorpio and into Sagittarius. I am assuming you have a chart of some kind in case you are not already familiar with the constellations. This section of the sky is littered with clusters, nebulae, and the densest star clouds in the Milky Way.

Saturn is an early evening object for now as it will shortly slip behing the sun. It is very, very far away, but the ring system is still visible. Mars, is a little higher in the early evening, but while closer (though it too will disappear behing the Sun soon) it is so much smaller that it now barely shows any semblence of a disk. Jupiter, as John mentioned, and Venus are both early morning targets. Jupiter is always a striking target, and you'll easily see its four largest moons, and at least its two main darker cloud belts. Venus will be showing a cresent at the moment.

Mid evening, and if you are at a dark site, you can have a shot at the Magellanic Clouds. These two satellite galaxies of our own Milky way are packed with their own clusters and nebulae. A slow scan of these will show up so much detail.

On one last note, I don't know you of your experience with scopes, so I apologise if you already know the following: Don't think that it is all about just ripping as much magnification out of the scope as possible. Your 4" dob will best serve you at low power with the stars proper, and leave the higher magnification for the Moon and planets. While I have 6 scopes that go from 2" through to 17.5", I love my smaller ones for the wide rich fields they provide, which is something my larger scopes can't.

Enjoy.

Mental.

fauxpas (Tony) · #6 20-09-2012, 07:40 AM

Cheers, thanks for all the info...

I'm using Stellarium which is great for a beginner as its easy to use... The scope only came with a 20mm and a 3x barlow so I'm getting a range of lenses and will test them out...

cheers again...

ZeroID (Brent) · #7 24-09-2012, 01:51 PM

My first 'real' scope was a 4.5" and it is still giving good views. Quite surprsing what you can pick up with it. Globs and even the hint of the well known nebulas, check out Orions Sword, the middle area, you might be surprised.

sil (Steve) · #8 25-09-2012, 07:45 AM

I've got a 4" table top dob (Orion) and I use 8mm/21mm Baader Hyperion eyepieces (got a 4.5mm TMB Planetary on its way too). I find it a far better scope than my larger one, so much easier to just get outside and start viewing immediately, no problems with cool down etc.

With my 8mm I've viewed Saturn (very recognisable), Mars and Jupiter (with four moons plainly visible). On the weekend I went looking for, and found, Neptune with this little scope. My first ever sighting of Neptune and I was over the moon! Apart from lots of star clusters I was able to view the Triffid Nebula and the Lagoon Nebula. I'm under light polluted skies and they were fain smudges through the eyepiece, until I popped on my Astronomik UHC filter and they really stood out. They weren't anything like the great colour photos, more like clouds in the sky but the lagoon was large in the eyepiece and I could make out a good amount of shape/structure.

The scope performs great during the day and you can get good views of the moon during daylight hours when its up. There are a lot of interesting things lurking in Scorpius. If you use something like Stellarium you can see what might be up in the evening and set yourself some targets: get some experience in star hopping to reach a target (tricky at first when the view in the eyepiece is upside down/reversed). Or just get outside and point to any part of the sky, look around, find something that looks interesting and sketch/map it out on paper (add some major stars you can see with the naked eye as reference points) then try to work out using Stellarium or a star map what it is you found. There are no rules really, except get outside and observe!

fauxpas (Tony) · #9 25-09-2012, 11:52 AM

Yeah, I'm finding stellarium to be absolutely necessary for a beginner... I do as much observing in stellarium as I do of the stars.

Can't wait for Saturn and Jupiter to be more observing friendly. I just want to eyeball them.

Suzy · #10 25-09-2012, 12:37 PM

Hi Tony

Here's some links for objects in our sky at the moment.

Highlights of the Winter Sky (some of these are not in our sky at the moment, but there are plenty of objects on the list you can still enjoy now).

Suzy's Observing Targets July/August 2012

Observing Targets for Each Month by Rob Horvat (this is brilliant!)
Take a further look on his web page and you'll come across his maps he did himself. Each constellation has lots of objects listed and the maps are very easy to follow. I have them printed out in plastic sleeves in a ring binder, I just love them.

With the exception of some bright clusters, it's essential to observe without the full moon in the way as Mental said- at mag -12 it just washes out a lot of those faint fuzzies. For planets, it doesn't matter. I find a moon app for my smart phone very helpful and watch for when the moon sets early or rises late. I really like Moon Phase Pro.
Otherwise, just have a look on the side blue menu bar of this web page for the moon rise and set times (but the app will allow you to plan better).

Double star observing is a lot of fun and there's some gorgeous contrasting pairs in our skies. For instance, Albiereo (beta Cygni) in Cygnus is a gorgeous contrasting orange & blue pair, and epsilon Lyrae- the famous double double. Another one, Brocchi's cluster (aka Coat Hanger cluster) in Vulpecula will be awesome thru your 4"- it really does look like a coat hanger! Go back thru Rob's observing list, say to about August, because many (incl. Albireo) are still viewable in our skies at the moment. There are two globular clusters in our sky at the moment that are definite "must see" objects- NGC5128 (Omega Centauri) and 47Tuc are the two biggest and brightest globs in our sky. Even in binoculars you can see them easily.

If you're a night owl or an early morning riser, you might like to catch Jupiter, Orion, The Pleiades cluster and the Hyades cluster- these two are big bright clusters that will look amazing through your scope. And while you're at it in that area, I'll issue you a little observing challenge...
The trapezium cluster of newborn stars is what powers the Orion nebula to make it so bright. With the naked eye, we see it as one star (theta orionis in the sword). Using some high magnification, you should be able to spot 4 little stars embedded within the nebula. If you're good, you may be able to split them to reveal 6. Look hard, the extra two are very tiny and sit very close to their brighter members.
Here's a great guide to help you! http://www.astropix.com/HTML/B_WINTER/TRAPEZ.HTM

Have fun!

fauxpas (Tony) · #11 04-10-2012, 10:39 PM

Couldn't see the forest for the trees

While playing around with some eBay eyepieces I came to realize I was going for too much magnification and was totally missing the clusters... Also, the supplied 3x barlow is pretty ordinary, hard to focus etc...

Observed M7 and M6 with a straight 10mm Plossl... Looking forward to searching for M8 and M20 tomorrow night...

I'm going to slowly work my way through the October targets but working outwards from Scorpius/Sagittarius so I can stay oriented... Kind of like putting together a jigsaw...

sil (Steve) · #12 11-10-2012, 11:26 AM

I use a 4.5mm TMB Planetary eyepiece on my Orion 4" tabletop. It's great, not quite as nice as my Hyperions but no disappointment either, especially for the price. Only real complaint is the 4" is too bright for Jupiter, need to chuck on a filter to darken it enough to see detail, otherwise its just a large white disc!

I've been able to find Neptune too with my 8mm eyepiece so that's worth a shot. Uranus should be easier (been waiting for clear skies to go hunting for it). It's also a fun exercise in star hopping and orienting yourself to the eyepiece and a starmap. The image is inverted in my EP so it takes a bit of extra care to star hop with my charts. Start with the widest field EP you have and work from there. It's a great way to learn about whats what and get an idea of what on your star chart you can see with which eyepiece and most importantly the scale on the chart compared to your field of view in the eyepiece.

Scorpius is really great with some amazing clusters, I haven't tired of looking around there and its a good place to orient yourself from. I guess once I learn other constellations better the sky will become more familiar to me and easier to use other constellations as jump points too.

fauxpas (Tony) · #13 11-10-2012, 12:14 PM

I've been waiting for favourable night skies... I'm suffering new equipment syndrome... A barlow arrives in the mail > cloudy for days... A plossl arrives in the mail > rain rain... [everyone suffers this "murphy's law" I suppose]

Can't wait for Saturn and Jupiter to come into easy views, Saturn next year

... Will a moon filter tone down Jupiter enough?

Yes I'm starting at Scorpius viewing M6 and M7 but the weather hasn't been great as I want to work out from there to M8 and M20, and possibly M16 ans M17...

I've been finding, as a beginner, having that spot to get familiar with is a great help...

sil (Steve) · #14 11-10-2012, 01:39 PM

I don't know if you've got the same 4" dob as mine or another brand, so it might not have the same f number. Mine is an f4 but my 76mm tabletop is f9 and Jupiter is fine without a filter. A moon filter would work (they're usually a green colour though? so that might hinder contrast in the bands on jupiter). A Neutral Density filter will tone down the brightness but not effect the colour.

Get up early in the morning and take a look at Jupiter, easy to spot. Depending on your scope, eyepieces and eyes it might look natural to you, or maybe too bright. Decide for yourself if you feel you need a filter. Also a barlow should "stop down" an eyepiece, making the image dimmer. In photography there is always a trade off in amount of light captured when you change focal length (magnification), so your best magnification eyepiece might be fine enough.