明天可是十年周期α-Monocerotids
Active : November 15-25;
Maximum : November 21, 15h00m UT (sol = 239.239°);
ZHR : variable, usually ~ 5, but may produce outbursts to ~ 400+;
Radiant : alpha = 117°, delta = +01°; Radiant drift: see Table 6;
V : 65 km/s
r : 2.4;
TFC : alpha = 115°, delta = +23° and alpha = 129°, delta = +20° (beta > 20° N); or
alpha = 110°, delta = -27° and alpha = 098°, delta = +06° (beta < 20° N).
Another late-year shower capable of producing surprises, the α- Monocerotids gave their most recent brief outburst in 1995 (the top EZHR, ~ 420, lasted just five minutes; the entire outburst 30 minutes). Many observers across Europe witnessed it, and we were able to completely update the known shower parameters as a result. Whether this indicates the proposed ten-year periodicity - with heightened rates in 1925, 1935, 1985 and 1995 - is real or not, only this year (or other future decadal returns) may tell, so all observers should continue to monitor this source closely.
The waning gibbous Moon on November 21 is very bad news however, as it will rise between mid to late evening across much of the world, ruining any chance of dark skies for watchers, because the radiant is well on view from either hemisphere only after about 23h local time. The expected peak time falls especially well for sites around and in the western Pacific Ocean, including eastern China, far eastern Russia, Japan, Oceania, and Alaska in North America. With the Moon so problematic, visual observing will be extremely difficult, but highly important, along with all other techniques, especially radio, which should readily detect any strong outburst from this source.
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