THE SOUTHWORTH PLANETARIUM
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Altitude:  10 feet below sea level
Founded January 1970
Julian Date: 2458808.16
2019-2020:  LVI
            "We can't wait for yesterday."


THE DAILY ASTRONOMER
Wednesday, November 20, 2019
Micro Meteor Outburst?
or
Alpha What?

The Alpha Monocerotids.
Never heard of these?
Be consoled.   It's a minor meteor shower that is not only centered around
an obscure constellation, but peaks around the same time as the much more
famous and furious Leonids.     Most years the Alpha Monocerotid "peaks"
are pathetic, and often don't even occur at all.  This year, however, this
usually underwhelming shower could very well produce a spectacular, though
fleeting, meteor storm.   If it does occur, it will last less than an hour
and the activity one observes will depend on the location.

[image: Alpha_Monocerotid_Radiant_1200px-e1573842083662.jpg]
*The Alpha Monocerotid "burst." * We could possibly experience a rapid
meteor storm produced by the usually unremarkable Alpha Monocerotid shower.
   The peak time will be around 11:50 p.m. on November 21st.     Observers
should look toward the eastern sky just beyond Orion's belt to see,
perhaps, a stunning meteor outburst.       Image: Sky and Telscope

The Alpha Moncertoids appear to emanate from a region around Alpha
Monocerotis, the "brightest" star in the modern constellation Monoceros,
the Unicorn.  This star, which lacks a proper name owing to its faintness,
is six times dimmer than Polaris.   It was assigned the alpha designation
in the Bayer system only because the constellation's other component stars
are even fainter.   Developed in the 17th century by Dutch cartographer
Petrus Plancius (1552-1662),  the faint Monoceros occupies the dark region
within the Winter Triangle, formed by Betelgeuse (Orion), Sirius (Canis
Major) and Procyon (Canis Minor).     Monoceros is so faint one would be
hard pressed to even notice it in completely dark skies.
The meteor shower named for the constellation's bright star is also obscure
mainly because the cometary dust tail from which the meteoroids originate
is thin and weaves around the area through which Earth revolves.
 Meteor showers occur when Earth moves through a field of particles a comet
-or, rarely, an asteroid-releases when moving through the inner solar
system.  We experience a meteor shower's peak when our planet passes
through the densest part of that stream.       Quite often, Earth will
actually miss the stream that the Alpha Monocerotid's unknown parent comet
left in its wake.    However, astronomers have noticed outbursts in both
1985 and 1995.     Two astronomers, Esko Lyytinen of the Finnish Fireball
Network and Peter Jenniskens of NASA's Ames Research Center, have paid
close attention to this shower for many years.   They noted that Earth's
position and other circumstances during this year's Alpha Monocerotid peak
time are very similar to those in 1995, the year of the last dramatic
outburst.  Hence, their prediction of another rapid meteor storm.

WHERE AND WHEN?
The peak should last no more than 40 minutes.    The best time to watch
will be around 11:50 p.m. EST. on November 21st.   Fortunately, being on
the US East Coast, we'll be well placed to see these meteors. Also, the
waning crescent moon won't rise until 12:03 a.m., so we won't have to
contend with any lunar light interference.    Unfortunately, the radiant
will be low in our sky:  at that time, Monoceros will be ascending in the
eastern sky.      More meteors are visible when the radiant is at or near
the zenith, the point directly overhead.  Consequently, observers in parts
of South America will be in the best position to observe this rapid peak.

We don't know what we'll see: perhaps dozens of meteors a minute!    The
1995 peak was 400 an hour, which is a bit misleading as the peak lasted
less than an hour and the 400 number was an extrapolation.   Meteor shower
rates are notoriously difficult to predict as we don't have direct
observations of the comet stream that produces them.  However. if you're
out on November 21st just before midnight, be sure to look over into the
east, in the dark region abutting Orion's belt.   There, if only for a few
minutes, one might behold a meteor spectacle greater than anything the
Leonids could possibly produce this year.....maybe.

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