SAO 119282 encountered the asteroid Hermoine today, April 3rd. Here is
a compilation of the preparations and the observations of a small but
enthusiastic band of observers. Place: Robert Ferguson Observatory
and Petaluma in Sonoma County, which is 75 miles north of the Golden
Gate Bridge in San Francisco, California. Observers and reporters:
Members of the Valley of the Moon Observatory Association and the Sonoma
County Astronomical Society.
- Friday, March 12
-
Say..... have any of you looked to see what the moon's situation is on
4/3 at 2:00AM? From what I can tell from my SKY program, SAO 119282 at
RA 12h14.5m DEC +8d 47'puts it in the arms of Virgo whereas the moon is
at the foot of Virgo. I figure that would put them roughly about 15
degrees away from each other! SAO 119282 is only magnitude 7.6 so it
would seem to me that seeing it might be a real chore with that much
light pollution.
- Monday, March 15
-
Where's the challenge if all the conditions are perfect? The moon will
be 30 degrees
away and 15.6 days old, i.e. 3.6 days past full. This will be annoying,
but
we should to able to find an 8th mag star. It does mean that everyone
should take lots of practice finding the star in question well ahead of
time, that is, when the sky is dark. If we all practice in good
conditions,
it'll be that much easier when the time comes. SAO119282 rises tonight
a
1830 PST and transits at 0100. There should be plenty of time for
practice
in the next 3 weeks.
Just look at it this way. You'll have no problem finding your
eyepieces,
star charts, etc. under that moon.
- Sunday, March 21
-
Interesting factoid of the day: the star is a triple but only the A
component
will be occulted.
Good bookmark for future asteroid occultation events is :
http://www.anomalies.com/iotaweb/index.htm
- Friday, March 26
-
We will have an informal (i.e not required) meeting Sunday 7:30 pm at
the
Ferguson Observatory for those interested in observing the event. We'll
discuss the technique of observing the occultation visually, then
everyone
will get plenty of practice finding the star. The waxing gibbous moon
will
be nearby, so it will be good practice. The star doesn't rise until
~5:45.
- Monday, March 29
-
Several observers met at the FO last night as a
warm up to the Hermione event. We learned (or relearned) a lesson in
the
difficulty in finding even naked eye stars close to a bright moon. Once
again, I was reminded of how useless a "right angle" finder is. (I also
learned my mini cassette recorder wasn't working.)
The 11 day old moon was about 25 degrees away from omicron virginis, a
4th
mag star. On the night of the occultation, the moon will be 16.6 days
old
(about the same brightness) and about 40 degrees away. With a lot of
effort, we all were able to find this star with binoculars. The
problem,
was that both telescopes we tried to use at the FO (Meade 10, ETX) had
those
useless right angle finders. We were not able to find a 4th magnitude
star
with a 10 inch telescope....pretty pathetic! The moon will be a major
complicating factor.
Here are some lessons learned. 1) Start with binoculars. ( I'll make up
some
charts designed for binoculars for finding omicron virginis.) 2) Use a
straight through finder! If you don't have one, borrow a telescope that
does. You'll want some magnification, so the telrads aren't as good,
but
they're better than a right angle finder. 4) If possible , use an
equatorial telescope. Index your setting circles on 2nd mag. Denebola
(beta leonis), then use the circles to find omicon. 3) Start early.
Give
yourself a couple of hours to set up of your equipment and find the
star.
- Thursday, April 1
-
Here comes your 19th nervous breakdown.
Three 30 sec. images taken between 2024 and 2124 PST on Thursday night
were
stacked. North is up. The frame is about 8 arc min. wide. SAO-119282
is
out of the frame to the west (left). Hermione is moving 26 arc secs.
per hour.
Don't forget extra batteries for your equipment and hairdriers for dew
removal . Set up early to avoid the breakdown.
Good luck everyone!
- Friday, April 2
-
On the IOTA web site tonight, the time is given at 10:25.0 UT (
2:25.0am).
This is a recent update, since the previous prediction had been 2:23.
Check
the web site later tonight to see if there is anything new.
http://www.anomalies.com/iotaweb/index.htm
Go to the Hermione section, but also go to the very bottom of the index
page
where it says, "check here for breaking news".
- Friday, April 2 21:23:33
-
hi all, things don't look good in the sky over here at FO (or soon to be
RFO)
any better weather at any of the other sites?
- Friday, April 2, 22:08:58
-
Here in Petaluma at 10:00 PM it looks bad too but not as bad as
20 minutes ago and the NW sky is clearing. We are going to wait 1 more
hour to see what develops.
- Saturday, April 3 09:35:48
-
The high clouds came and went through the early part of the evening. I
went
up to my observatory about 11:30. The sky looked promising. There were
thin high clouds but Hermione was bright and clear on the computer
screen.
I followed the asteroid approaching the star using the CCD camera until
a
little after Geroge arrived at midnight.
We switched to the photoelectric phototmeter. We were ready, since
George
had worked out the glitches with the interface box and software when he
was
up here for the dry run last weekend. The high clouds started to
thicken
just as the data started to roll across the screen. For the next two
hours
we watched the signal drop and the clouds become more opaque. By about
1:30, the signal from the star was gone.
We sat around talking and hoping until after the scheduled time of the
occultation, then packed up and when home to bed.
- Saturday, April 3 9:41:00
-
It was touch-and-go all evening, but at the moment of truth the clouds
came in (after 1:45 and before 2:00). It was a lot of fun, though and I
learned a lot. Lets do it again!. It was amazing to me that until 1:45
I could see the star through the telescope even though if I just looked
around I couldn't see a single star in the sky.
- Saturday, April 3
-
The sky wasn't very clear, as the previous e-mail stated. We viewed
Mars and when we could no
longer see it in the 10" Meade, we decided to call it a quits This was
about
1:50 a.m. pst. It was a great experience preparing and waiting. Look
forward to the next one. We locked up about 2:15 a.m.
- Saturday, April 3rd 11:29:59
-
- We did observe one occultation in the data, which we ran just for the
practice
during the time of the occultation:
At 10:32:29.94 UT the sky (which was brighter than the star which we
observed
earlier) began to dim until it was completely occulted at 10:33:26.52 UT
by a
nearby tree.
All those digits are absolutely necessary :-)
FYI,
Hermione was the daughter of Helen and Menelaus, wife of Achilles' son
Neoptolemus.