Geminidi će ove godine biti aktivni od 4. do 17. decembra sa maksimumom 13. decembra. S obzirom na to da će 13. decembra Mesec biti mlad, a da radijant izlazi iznad horizonta već od 18.30 po srednjoevropskom vremenu, ovo je idealna prilika za posmatranje, pod uslovom da meteorološki uslovi dozvole.
Međutim, osim Geminida, u periodu od 10. do 14. decembra moguća je i aktivnost materijala koji potiče iz komete 46P/Wirtanen. Radijant ovog roja ima koordinate α = 357,0° δ = +3,6° i nalazi se u ribama. Meteori bi trebalo da su spori, i može se očekivati nekoliko desetina meteora na sat u više maksimuma (jer Zemlja nailazi na materijal koji je kometa ostavila svojim prolascima 1915, 1921, 1927, 1934, 1941, 1947. i 1954. godine).
Prenosimo, uz dozvolu autora, informacije koje je Mihail Maslov izneo o ovoj mogućoj aktivnosti. Maslov je, inače, poznat i po tome što je uspešno predvideo pojačanu aktivnost Drakonida ove godine:
I'd like to remind that this year during the period December 10-14 some meteor activity caused by the comet 46P Wirtanen trails is possible. The Earth will come close to the 1915, 1921, 1927, 1934, 1941, 1947 and 1954 trails of this comet. These trails are not dense, but ejection velocities of their particles lie in the favorable area of 8.3-13.7 m/s.
Computed maximum times are the following: 14.12.2012 0:02 UT for 1927 trail, 13.12.2012 12:30 UT for 1934 trail, 12.12.2012 10:20 UT for 1941 trail and 11.12.2012 6:21 UT for 1947 trail. The trails are quite perturbed, so accuracy of these timings are not very high and perhaps it shows that during 10-14 December 2012 the comet 46P stream is
expected to produce some activity with radiation area around RA=357.0°, Dec=+3.6°, Vg=8.7 km/s. This point is a bit to the east from stars hexagon in Pisces. So far, meteors from this shower should be extremely slow and visible mostly in the evening time almost equally from both hemispheres.Intensity prospects are very uncertain. It could be very roughly estimated as several dozens meteors per hour, probably with several peaks within 10-14 December.
Some more details and graphs can be found here: http://feraj.narod.ru/Radiants/Predictions/46p-ids2012eng.html
Written by Vladimir Burgić
