Some astronomical data concerning periodic comet Giacobini-Zinner
and last years outburst and possible activity for 1999. As you will notice the
conditions now are excellent while there is no disturbing moonlight and the radiant
high in the sky. Be sure to start observations about one hour after sunset (18 UT)
which is about one hour before the position of the solar longitude of the outburst of 1998.
Please note some activity could very well appear hours after the prospected time
of 19 UT so please keep observing the remainder of the night!
As Peter Bus pointed out slightly enhanced activity
might be observed at the preceeding (7/8) and following (9/10) night too.
| Year | Nodal passage | Outburst |
|---|---|---|
| 1998 | October 8 at 21 UT | October 8 at 13 UT (actual) |
| 1999 | October 9 at 3 UT | October 8 at 19 UT (predicted) |
| Data for location Utrecht (52 N ; 5 E) | |
|---|---|
| Twilight | Time |
| Sunset | 17:02 UT |
| End of civil twilight | 17:36 UT |
| End of nautical twilight | 18:15 UT |
| End of astronomical twilight | 18:55 UT |
| Radiant RA=17h30m ; DC=54 (52 N ; 5 E) | ||
|---|---|---|
| Time (UT) | Elevation (degrees) | Azimuth (N=360) |
| 18 | 72 | 288 |
| 19 | 63 | 292 |
| 20 | 55 | 298 |
| 21 | 47 | 304 |
| 22 | 40 | 310 |
| 23 | 33 | 318 |
| 0 | 27 | 325 |
| 1 | 23 | 333 |
| 2 | 19 | 342 |
| 3 | 17 | 350 |
| 4 | 16 | 360 |
 |
