[meteorite-list] Easy Observing Ceres Tonight (28-29 May)

From: MexicoDoug_at_aol.com <MexicoDoug_at_meteoritecentral.com>
Date: Sat May 28 17:29:21 2005
Message-ID: <190.40e216bc.2fca3cab_at_aol.com>

Hola list,
 
Ceres is still 2.5X brighter than Vesta tonight and twice as far as Vesta!
Take advantage of this to collect a memory of Ceres. Just a quick message
hoping you get to see the main mass of the asteroid belt -Ceres- tonight.
 
That is starting right about now in Europe and lasting until nearly 3:00 AM
local times. Ceres normally is too dim to find with typical consumer
binoculars, but as has been discussed it has just passed opposition (it opposes the
Sun in Earth's sky). So we are still near a "full Ceres" at 99.4%
illumination as happens at opposition, not to mention being so close at a miniscule
1.75 AU away from this object which has a 2.75 or so AU average distance from
the Sun. The other benefit is that at opposition it is highest in the sky
around midnight. Well, this situation is quickly vanishing as the cosmic
merry-go-round continues. We had overcast skies during opposition about three weeks
ago when Ceres reached near 7.0 magnitude. It is now at 7.35 magnitude -
about only half as bright as then, and these have been the first few nights
since the nearly full moon has delayed enough to five us 3 or 4 hours of peace,
not to mention being a Saturday night which covers the casual observer with
Sunday relaxation the next day after an astronomy night, if necessary.

Actually at 10:00 -11:00 PM wherever most of you are, will be around the
best time. 7.35 magnitude is about the last chance to make this fun (unless you
have more powerful optics and don't mind hauling them).

I've printed out two finder charts for 2005 May 29 03:00 Universal Time
(10:00 PM CDT May 28 today), which should give you no trouble finding Ceres, the
little pinpoint it will be. Every 4 days it is losing a tenth of a magnitude
now - in other words - give it three weeks or so to to be half as bright as
tonight...and then there will be a Moon to deal with soon enough.

The big picture first finder chart
link:
http://www.diogenite.com/2005-5-29-125UT.JPG
will work to orient one as Ceres is still in Libra, near Virgo. It sort of
makes a triangle with Jupiter (mag=minus 2.3, brightest astro in the sky and
unmistakable) and Spica (Ist mag), the nearest very bright star nearby
(Arcturus (0th magnitude) also isn't to far away and is the brightest star to the
left while Jupiter is to the right. Ceres is the dimmist object at 7.35 mag,
the stars are only show twice as bright mag=6.5 min, to aid in hopping about
the sky.

The second finer angle finder chart
link:
http://www.diogenite.com/Ceres45Deg.JPG
has Spica in the upper right good for reference, (near the ecliptic which is
traced) and has all the stars in the field up to the 8th magnitude visible.
In other words everything it includes everything half as dim as Ceres or so
that you might be able to see in the binoculars. The two concentric red
circles around Ceres show the sizes of a 5 degree and a 10 degree field of view,
the typical ranges in cheap binocs, which ought to give a good reference of
what you would see when on target if you use these convenient eyes into the
sky.

Enjoy! Hope all have a celestial weekend!
Clear minds,
Doug
 
Received on Sat 28 May 2005 05:29:15 PM PDT