6 replies to this topic

[Sky King]

I decided to try a DSLR with my Askar FRA300 Pro 60mm scope. There were challenges getting it set up and working. I have a unmodified Nikon D750 and with the Askar there just isn't much back space. Pixel scale: 4.1 arcsec/pixel is a lot.

 

Then the wide 6.88 x 4.6 degree images seemed to attract airplanes flying through the frame and overhead power lines. I do like the huge star fields when everything goes well. 

 

I found SH2-240, the Spaghetti Nebula, a wide field target. Then the area around comet 29P. I used ASTAP to see if the comet was in the frame and found this hoard of asteroids. I then checked all the wide frame images for asteroids. SH2-240 also had a lot. M42 had none. Betelgeuse had just a few.  I remember reading that when looking for new comets/asteroids a wide field setup had been frequently used. I was surprised to see this many asteroids in one image.

 

 

Sh2-240 area notated by ASTAP:

 

 

 

 

29P near Subra in Leo notated by ASTAP:

 

 

[Sky King]

Star field around  SH2-240. (Now I need many more hours of imaging here to bring out the nebula.)

 

 

Edited by Sky King, 21 March 2025 - 03:22 PM.

[Tapio]

Just imaging Suomi asteroids (found  by Yrjö Väisälä , Liisi Oterma and others in 1939–1944).

 

Many of the asteroids in your image are only 'potential' asteroids as they are so faint. But I'm sure you are aware of that.

[Sky King]

Just imaging Suomi asteroids (found  by Yrjö Väisälä , Liisi Oterma and others in 1939–1944).

 

Many of the asteroids in your image are only 'potential' asteroids as they are so faint. But I'm sure you are aware of that.

Thanks for the information! This just came about by accident, when I tried to get my new-to-me wide field imaging going, as mentioned above.

 

I know that there are "asteroid families," where separate asteroids can be traced back to the same original large body. And I believe once they are able to calculate orbits, an asteroid may be named. I will look up the reference. Any asteroid books you can suggest would also be appreciated. Thanks! 

 

Edit: From wiki:  (Very cool, thanks for posting!)

 

1656 Suomi (prov. designation: 1942 EC) is a binary Hungaria asteroid and sizable Mars-crosser from the innermost regions of the asteroid belt. It was discovered on 11 March 1942, by Finnish astronomer Yrjö Väisälä at Turku Observatory in Southwest Finland, who named it "Suomi", the native name of Finland. The stony asteroid has a short rotation period of 2.6 hours and measures approximately 7.9 kilometers in diameter. In June 2020, a companion was discovered by Brian Warner, Robert Stephens and Alan Harris. The satellite measures more than 1.98 kilometers in diameter, about 26% of the primary, which it orbits once every 57.9 hours at an average distance of 30 kilometers.

Edited by Sky King, 21 March 2025 - 11:09 PM.

[Tapio]

There are indeed many asteroid families.

But what I called ' Suomi asteroids is just a group of asteroids,  (and few comets) that Yrjö Väisälä, Liisi Oterma and some others discovered.

They discovered over 800 but 'only' 128 are listed in MPC.

Here's some more info of Yrjö Väisälä's work:

https://en.wikipedia...ki/Yrjö_Väisälä

 

After last night I have now imaged 20 of them,

One of them is named after my home town, Tampere (1497 Tampere).

[RedLionNJ]

I decided to try a DSLR with my Askar FRA300 Pro 60mm scope. There were challenges getting it set up and working. I have a unmodified Nikon D750 and with the Askar there just isn't much back space. Pixel scale: 4.1 arcsec/pixel is a lot.

 

Then the wide 6.88 x 4.6 degree images seemed to attract airplanes flying through the frame and overhead power lines. I do like the huge star fields when everything goes well. 

 

I found SH2-240, the Spaghetti Nebula, a wide field target. Then the area around comet 29P. I used ASTAP to see if the comet was in the frame and found this hoard of asteroids. I then checked all the wide frame images for asteroids. SH2-240 also had a lot. M42 had none. Betelgeuse had just a few.  I remember reading that when looking for new comets/asteroids a wide field setup had been frequently used. I was surprised to see this many asteroids in one image.

 

 

Sh2-240 area notated by ASTAP:

 

 

Preview_SH2-240_60.0s_Bin1_ISO400_20250319-194633.jpg

 

 

29P near Subra in Leo notated by ASTAP:

 

 

Preview_29P_120.0s_Bin1_ISO400_20250319-195433.jpg

Your app is only annotating numbered asteroids at this point.  Average magnitude is about 20.

 

When we include all the known, but not yet numbered, asteroids, the density increases more than tenfold. And the average magnitude drops to 22.

[Sky King]

Your app is only annotating numbered asteroids at this point.  Average magnitude is about 20.

 

When we include all the known, but not yet numbered, asteroids, the density increases more than tenfold. And the average magnitude drops to 22.

Thanks!  Wow, that's a serious number of asteroids then.