| Object : | Comet, C/2020 F3 Neowise |
| Coordinates/Direction : | - |
| Object size : | - |
| Object magnitude : | - |
| More to know : |
You can read more about the comet on Seiichi Yoshida's homepage:
http://www.aerith.net/ comet/ catalog/2020F3/ 2020F3.html |
| Exp. time : | 1 second at ISO200 |
| Image process tool : | IrfanView. |
| Processing : | Increase the contrast a bit. |
| Comment : |
First night we tried to catch the comet.
Lot of clouds as usual but the comet is hiding behind the clouds to the left.
8 degrees above the horizon this night, that is very low.
Have a look here how I plan my comet observations / photographing:
|
| Date : | 2020-07-16 |
| Time (UT) : | 23:28 |
| Mount : | Manfrotto tripod, manfrotto tripod project |
| Exp. time : | 241x2 seconds at ISO400, of these I used 75x2=150 seconds. |
| Image process tool : | AstroImageJ with my own macros, Fitswork, IrfanView. |
| Processing : | demosaic, align rgb, no dark or bias, use dithering instead, median stack. |
| Comment : |
It surprised us how bright it was, what I have read earlier is that most people couldn't see it by naked eye.
And this is from a light polluted city.
I took many photos of it with small changes of focus, because it's very difficult to focus precise manually.
This photo is taken from the window in the living room, very comfortable.
I also tried 4 seconds exposures, but that was too long and the comet core get elongated because of its speed and that I didn't use a motor driven mount. |
| Exp. time : | 1 second at ISO400 |
| Image process tool : | AstroImageJ with my own macros, Fitswork, IrfanView. |
| Processing : | Nothing. |
| Comment : |
This is about how it looked to us with naked eye.
13 degrees above the horizon. Looking North above the big light polluted city.
The horizon is just below the bottom edge of the photo.
This is the first time ever I have seen a comet during the summer (in Sweden we have our dark nights at winter), so the comet is really bright.
According to some reports I have read it had a magnitude of 1.6 this night.
The field of view of the camera / lens is 6.9 x 4.5 degrees.
The tail looks to be 1.5 degree long, that is three times the moon's diameter.
I also found this which could be interesting for you to look at:
|
| Exp. time : | 4 seconds at ISO400, at f/4 |
| Image process tool : | IrfanView. |
| Processing : | Cropped about 50%. |
| Comment : |
We had to wait 5 days until we got our next clear sky.
Now the comet was so weak that it couldn't be seen by naked eye. I changed to a shorter lens to get a wider view.
The comet is almost exactly at the Northern direction, 17 degree above the horizon. |
| Comment : |
A crop around the comet from the single photo above.
The bright upper right object is a 4.7 magnitude star. |
| Exp. time : | 51x4 seconds at ISO400, at f/4 |
| Image process tool : | AstroImageJ, Fitswork, IrfanView. |
| Processing : | Aligne, Median stack, crop, 1:1 pixel scale. |
| Comment : |
To reduce the noise in the background I used all 51 images I took and stacked them together.
With that I increase the exposure time from 4 seconds to 204 seconds.
That decrease the noise and I can then increase the contrast much more to see the details (which I haven't done here).
Because of the stacking process which use median stacking all stars disappear.
The images are aligned at center of the comet's core.
The comet move a bit between each image and the stars appear on different places after stacking and then cancel out. |
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