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Beginner backyard astronomy science experiments

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#1 mostlyemptyspace

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Posted 18 April 2014 - 10:58 AM

Hi all. I've been doing visual astronomy for a few years now, and recently dabbled in astrophotography. I am also interested in actual science, so I've been doing some research on ways I can do sort of fun experiments in my back yard. I've been asking around, and everyone says this is the forum to ask.

The first thing that jumped out at me was spectroscopy. It seems with the SA100 + RSpec you can pretty much jump right in. I would love to be able to use this to get a sort of high level profile of a star, e.g., it's chemical makeup, rotation, mass, type, distance, etc. Is this something I can expect to be able to do with this setup? I'd love to hear people's experience with spectroscopy.

Then, I found this Target Asteroids! project, which seems fun and useful, but I'm wondering if I can even see asteroids. I have a Celestron Nexstar 8SE. Can I even detect asteroids? What magnitude are they typically? Again, I'd love to hear someone's feedback who's done this.

What would you guys recommend someone who pretty much only does visual observing wanting to get my feet wet with some actual experiments or scientific observing?

#2 Rich (RLTYS)

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Posted 19 April 2014 - 06:53 AM

Why not observe Variable Stars? You don't need a lot of equipment and you can make a real contribution to Astronomy.

Rich (RLTYS)

#3 Ed Wiley

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Posted 20 April 2014 - 03:22 PM

Variable stars is a good start, check with AAVSO for both visual and CCD (and DSLR for that matter). Another route is measuring double stars, check out the journal JDSO (free Google same) to see what amateurs are doing. The nice thing about doubles is that you get to publish your own measures. The nice thing about AAVSO programs is that you can compare your results with others and they have a bunch of on-line courses for members.

I stayed away from spectrometry until I had some experience with variables and doubles. But that's me. You might feel differently.

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#4 lee14

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Posted 21 April 2014 - 10:31 AM

I'd recommend variables as well. The AAVSO site will tell you all you need about techniques and data submission. I've been making visual estimates for more than twenty years, and it can be quite habit forming. You may also want to check out zooniverse.org for 'citizen science' projects.

Lee
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#5 mostlyemptyspace

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Posted 21 April 2014 - 11:43 PM

What kind of seeing conditions are necessary for visual star observing? I live in San Diego, CA, so skies are grey. We don't get a lot of cloudy nights, but seeing can be not so great.

Also, is my equipment good enough?

#6 Rich (RLTYS)

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Posted 22 April 2014 - 05:24 AM

Seeing isn't a major factor in VSOing and whatever equipment you have will work just fine. Remember in VSOing you can use anying from your unaided eyes, binoculars, to the largest scope you have.

Rich (RLTYS)

#7 lee14

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Posted 22 April 2014 - 09:14 AM

Light pollution or moonlight isn't as much of a hinderance as it is when observing extended objects. There will be a loss of limiting magnitude of course, but much of that can be compensated for by using higher magnification. Higher powers should also be employed when viewing stars near the threshold of visibility. The sky background will darken, producing improved contrast. On bright nights, just stick to the brighter variables, or those near maximum. Save the faint ones for moon-free nights and late hours when the light pollution tends to diminish somewhat.

Lee

#8 NJScope

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Posted 22 April 2014 - 08:23 PM

Regarding asteroids, yes you can easily see many main-belt minor planets with your Nexstar 8. Since they are literally a moving target, the visual magnitude varies according to their distance from Earth, albedo, size and shape. Many rotate with synodic periods less than 6 hours so that light curves which measure differences in the changing surface area can be recorded in a single evening. Although there may be some examples where this can be accomplished visually, for the most part this is best performed using a ccd camera.

#9 mostlyemptyspace

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Posted 22 April 2014 - 08:46 PM

Regarding asteroids, yes you can easily see many main-belt minor planets with your Nexstar 8. Since they are literally a moving target, the visual magnitude varies according to their distance from Earth, albedo, size and shape. Many rotate with synodic periods less than 6 hours so that light curves which measure differences in the changing surface area can be recorded in a single evening. Although there may be some examples where this can be accomplished visually, for the most part this is best performed using a ccd camera.


So I just ordered a ZWO ASI120MC. So what are some brighter asteroids I could find with my setup?

So let's say I could find it in my scope. Would I see it moving visually? How would I be able to tell it apart from a star?

Then, would I just take a few seconds of video of it every hour for a few hours? Then what?

#10 NJScope

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Posted 23 April 2014 - 11:31 AM

I am not familiar with that particular camera but suspect it can probably reach mag 11 with 1 minute exposures. The best website to obtain a nightly selection of asteroids is Calsky. Be sure to adjust the user site to your location and user level to "astronomer". The hourly motion of each target is provided so that you can gauge its speed across the field-of-view. Main belt asteroids are relatively slow so that 1 minute exposures are not problematic. Near Earth Objects (NEOs) on the other hand might require sub-minute exposures depending how close they are. Hopefully the software provided with the camera will allow you to automatically save individual images. It is not uncommon to collect hundreds of images over the duration of each nightly run and depending upon the rotational period many sessions to get full coverage of a light curve. Check out "The Minor Planet Bulletin" for examples of light curves generated from a wide range of asteroids.

#11 starquake

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Posted 14 May 2014 - 05:42 PM

There's a fine book from Robert Buchheim: The sky is your laboratory, from Springer-Praxis. It lists many interesting astronomy projects from variable star observing through occultations to supernova patrolling.

#12 btieman

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Posted 14 June 2014 - 02:44 PM

\I am also interested in actual science, so I've been doing some research on ways I can do sort of fun experiments in my back yard.


I would say 95% of what I do is science related :) I haven't had an eyepiece in my telescope for over 5 years...it's always a camera. Once in a while I take a pretty picture but mostly I acquire data.

Photometry is a great technique to learn. If you can image, photometry is pretty simple. Variable stars are probably the simplest. Then you can quickly advance to time series photometry and generating light curves over the course of hours. This opens up binary star periods, exoplanet transits and asteroid rotations.

Exoplanet transits can be submitted here: http://var2.astro.cz/ETD/

Asteroid periods can be published here: http://www.minorplanet.info/call.html They also maintain a list by quarter of asteroids that need light curve data submitted. Many might be out of reach of an 8" scope, but many aren't. Also, it's useful to get new data on known targets. There are algorithms that can generate a 3D model of an asteroid given light curves from different perspectives. A bit experimental, but some results have looked pretty good.

Spectroscopy is a different beast. I have an SA100 and a Spectra-L200 built from a kit that I use. I've measured the spectroscopic double Beta Auriga with the Spectr-L200 as detailed here: https://sites.google...c-binary-bet... (I got bogged down in mentoring a robotics team so the Project of the Month thing broke down. I'll be redoing that site at some point and adding other science related projects I've done as well.) Be stars are good spectroscopic targets and of pro-am interest. SN confirmation is interesting as well. Lots of places to go with spectroscopy, but it is a bit of investment and has deeper equipment challenges than simple imaging.

Other fun projects of varying difficulty include following Hubble's Variable Nebula, measuring planet rotations/moon orbit periods, trying to image dust disks (http://blogs.discove...n-solar-system/), if you've got a *dark* site imaging galaxy streamers (http://cs.astronomy....rom-galaxy.aspx)

Just some idea. I tend to dabble across the entire spectrum. Lately I'm interested in generating HR diagrams. I've written my own software for light curve generation so I can get light curves from every star in the field with a few button clicks. It can easily reduce exoplanet transit data. I'm in the process of using the photometry data generated to generate color data for all stars int he field to generate an HR diagram. The data won't make sense on most fields since in most fields stars are vastly varying distances, but my hope is to be able to reduce images from clusters where most stars will be equivalent distances. Other amateurs have already done this as well.

I use a CPC1100 but most of these should be doable in an 8" scope almost as easily.

Which direction you take strongly depends on if your goal is self edification or to contribute to the communal body of knowledge.






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