What telescope for asteroids?

[Diddykong]

Hi all,

 

I'm picking up an ED 80 or similar for some astrophotography and am also interested in asteroid finding.  Is there a particular type of telescope that's well suited for this?

[jonathan]

I know very little about the subject but if you're going for visual asteroid hunting then probably the biggest you can afford / handle!

[Ships and Stars]

I don't think there is really a specific type of scope for asteroids or comets, but if you have the ED80 for imaging and want something for visual, then aperture is your friend as Jonathan mentions. Some people like refractors, but far as I know, they don't go beyond 150mm aperture without spending an insane amount of money.

I've owned a number of dobsonians, and most will agree they give by far the most aperture for the money, are super easy to use, and you can view many of the fainter, more difficult DSOs like nebulae and galaxies as well as asteroids and comets. They will do planets as well, so a dobsonian is a good all-rounder except for astrophotography. A 10" dob (254mm aperture) is more or less the standard for deep sky. I have the 300p 12" (305mm) and 500p 20" (508mm) Skywatcher dobs and can't fault them for the price. The 12" SW flextube dob to me is very portable, some might say it's too big, but the 20" is also portable (for a 20" dob, though a workout!) and gives some mind-blowing views under dark skies.

You can't go far wrong with a 10" dob, especially for price, and if it's not your thing, then you can always get most of your money back out of it, but they are very popular for a good reason and will show you a lot of deep space objects, plus you can easily take it to a dark site if you drive and really let it show you what's up there. 

Edited April 28, 2020 by Ships and Stars

[Paul M]

Most asteroids are uninspiring and all show nothing more than star like points in a telescope. But they can be  fun to find and track, particularly fast moving ones can make nice time lapse imaging project.

The biggest down side is that the vast majority are faint or very faint and might be difficult to identify by studying a star atlas or planetarium software. But that is the fun bit. Imaging and sketching star fields to see what changes over hours or days. It can be very rewarding, if time consuming.

For visual you'll be wanting as much aperture as you can muster but even the little 80mm will drag faint asteroids out of the darkness with longer exposure/integration imaging.

You can image through a bigger scope too, so for all round asteroid hunting performance there are better choices than an 80mm refractor, it limits your options visually. I'll stop short of recommending something else. There are as many opinions on telescope choice as there are active members of SGL

 

 

[Dr Strange]

The questions become is this for visual and what you want to do, visual or AP. If it is AP then what mount you will buy as well (for astro photography [AP| the mount is where you want to spend most of your money) and that will dictate your scope choice.

If it is visual then the default will be the biggest scope you can afford and handle. Usually that will be a Dob but understand that the bigger the Dob the heavier and bigger it becomes. In general if it is too big and/or too heavy then you will be looking for excuses NOT to observe instead of reasons TO observe. 

It is likely better to do EEVA with a tracking mount for asteroids. That way you can capture images using the "lucky imaging" method where you take a lot of short exposures and then, in this case, create an animation where you can track the asteroid as it moves across the sky relative to the surrounding stars. For that a 203mm SCT plus the best equatorial (EQ) mount you can afford and the best cooled ZWO ASI CCD you can afford will be your best option. 

[cletrac1922]

3 hours ago, Dr Strange said:

The questions become is this for visual and what you want to do, visual or AP. If it is AP then what mount you will buy as well (for astro photography [AP| the mount is where you want to spend most of your money) and that will dictate your scope choice.

If it is visual then the default will be the biggest scope you can afford and handle. Usually that will be a Dob but understand that the bigger the Dob the heavier and bigger it becomes. In general if it is too big and/or too heavy then you will be looking for excuses NOT to observe instead of reasons TO observe. 

It is likely better to do EEVA with a tracking mount for asteroids. That way you can capture images using the "lucky imaging" method where you take a lot of short exposures and then, in this case, create an animation where you can track the asteroid as it moves across the sky relative to the surrounding stars. For that a 203mm SCT plus the best equatorial (EQ) mount you can afford and the best cooled ZWO ASI CCD you can afford will be your best option. 

 

Agree with Dr Strange

I have a ED80 on a EQ5pro mount for AP, and also use the same mount with my Coronado Solarmax11

When out with my club, doing presentations in primary schools and scout groups, use primarily my 10'' Flex Dob

The Dob is quick and easy to set up, especially when have a bunch of 5yo's screaming out to have a look

With my EQ5 mount, I have also purchased the WiFi adapter, and downloaded the SynScan APP

I also use a right angle finderscope, especially with the Dob, as not laying on the ground, when trying to spot something which is overhead

Have attached pic of my ED80 and 10" Dob, taken at club field days, also WiFi adapter 

John

 

[Stu]

I would think something like a C925 on a decent Goto EQ Mount (HEW5?) would be handy for asteroid hunting either visual or imaging. Plenty of aperture to pull in the faint asteroids and Goto to find them more easily!

[Diddykong]

Thank you all for the replies.  Very informative.

 

I am getting the HEQ5 Pro mount.  My main interest in astrophotography of galaxies and nebula, hence the ED 80 purchase, however I was hoping to track and find asteroids using software where you take multiple images of the sky and overlay them to see any changes.  Looks like a good lot of fun.

 

So would the ED 80 or williams optics 73 (not decided on which yet) be able to carry this out?

[Dr Strange]

For larger/brighter asteroids the ED 80 will do fine. Though I would suggest you consider the Skywatcher Esprit 80 or 100. Reason being is that it comes with literally everything you need to image or view except for a camera or EP. So when you factor in those costs that would be needed to added to the 80 or WO then you are much closer to the cost of the Esprit than you thought. In addition the Esprit series uses FPL 53 and Schott glass which are top shelf and it it a true APO instead of a ED. 

[Owmuchonomy]

A reduced ED80 is fine for nebulae but for galaxies you may want to consider something of slightly longer focal length. The bigger Esprits as mentioned for example.