| Object : | Comet, 123P/West-Hartley |
| Coordinates/Direction : | Northern Sky |
| Object size : | 2.18 km |
| Orbital period : | 7 years |
| Perihelion : | 2.16 AU, shortest distance to Sun |
| Apparent magnitude : | ~16, peak, in Leo, January 2019 |
| Mass : | - kg |
| Discovered by : | Richard M. West / Malcolm Hartley, Europe May 1989 |
| More to know : |
More info at Seiichi Yoshida's homepage:
http://www.aerith.net/ comet/ catalog/ 0123P/ 2019.html
Wikipedia:
https://en.wikipedia.org/ wiki/123P/ West-Hartley |
| Exp. time : | 51x60 seconds at ISO1600 |
| Image process tool : | AstroImageJ with my own macros, Fitswork, IrfanView. |
| Processing : | demosaic, one point aligned at center star, flat cal, no dark or bias, use dithering instead, median stack. |
| Comment : |
Another night with clear sky and I still have the comet outside my balcony.
Magnitude is now 12.9
according to CdC (Skychart).
A 800 x 800 1:1 crop from full frame sensor.
It's moving faster now because it's closer to the Earth, you see how elongated it is because of its speed.
|
| Exp. time : | 40x30 seconds at ISO1600, dithering mode |
| Image process tool : | AstroImageJ with my own macros, Fitswork, IrfanView. |
| Processing : | demosaic, one point aligned at center star, flat cal, no dark or bias, use dithering instead, median stack. |
| Comment : |
This comet wasn't easy to catch, weak, strong light pollution and low to the horizon.
Magnitude 12.9
according to CdC (Skychart).
A 800 x 600 1:1 crop from full frame sensor, just outside the inner red circle below.
I must say that I'm surprised that it was possibly to catch this weak comet from my light polluted balcony.
|
| Date : | 2019-01-18 |
| Time (UT) : | 22:37 (23:37 CET) |
| Comment : |
With the CdC (Skychart) software you can simulate and see where you find the comets.
The inner red circle is 0.5 degree diameter, the outer is 2 degrees.
The rectangle is the field with a fullframe sensor at focal length of 910 mm, about 2.2 x 1.5 degrees. |
| Date : | 2019-01-18 |
| Time (UT) : | 22:37 |
| Comment : |
My friend Hans has provided the nearby star magnitudes as a comparison to the comet. Source APASS.
Based on this, Hans estimates that the comet's magnitude is about 13.
Thanks a lot Hans for the correction of my mistakes earlier! |
| More to know : |
AAVSO homepage with APASS:
https://www.aavso.org/ apass |
English
Credit: software 'Comet for Windows' from Seiichi Yoshida
(Place the cursor over the image to get info)
