Tuesday, November 3, 2009

3 November 2009

Observing LocationDrip Rock, Central Park, New York, NY
Lat.: 40.767523
Long.: -73.976345
Elev.: 66
This location is very closed in with trees. Most of the view is straight up. There is some open sky out over the Wollman (now Trunp) skating rink out to the northeast which is where the moon was.
Observational Period2040-0100 EST
Atmospheric Conditions
Cloud CoverClear
Temperature51° F
dropping to
44 ° F
WindLight Breeze
HumidityModerate
Barometric Pressure30.13" Hg
Rising
Feels LikeCool

TransparencyExcellent
SeeingI
Peter reported some wavering that I did not notice
InstrumentsNaked-eye – Charlie
Takahashi 102mm F/8.2 refractor - Peter
  • 1.5" TeleVue Plossl 32mm, ##° FoV, 31.8x
  • 1.25" TV Nagler 13mm, 82° FoV, 97.7x
  • 1.25" TV Plossl 7mm, 82° FoV, 181.4x
Observing PartyCharlie Ridgway
Peter Tagatac

The sky looks strange from here. From TotL Auriga is normally scintillating just above the treeline but from here it is much higher in the sky. It doesn’t seem like Taurus should be awake yet but the Moon must be up around 40° and is going to occult M45 even higher up on the upper edge of Taurus. Part of it is that we monkeyed with the clocks on Sunday so it isn’t the same time today as it was this time last week. And with the winding road and higher treeline it is harder to orient myself to the compass. I can’t even see Jupiter from here, it must be behind a building out on 5 Ave.

TargetJupiter
ConstellationCap
CategoryPlanet
Time
yyyymmdd.hhmm		20091103.2105 EST
Comments
Object
Class		Classical Planet
Elongation°
Distance
Light Time
(from Earth)		4.8136 AU
m s
Distance
(from Sun)		5.0175 AU
Angular Size40.9"
Magnitude-2.5
Central Meridian
I/II/III		195.07°/101.75°/222.42°
Altitude21° 8'
I had walked north on the park drive as far as 72 St looking for Peter in case I was at the wrong rock. I knew of another outcrop of rocks farther up the road although I was reasonably certain I was in the right place. On the way back south I saw Jupiter hanging over the hotels of CPS.

TargetMoon/M45 Occultation
ConstellationTau
CategoryLunar
Time
yyyymmdd.hhmm		20091103.2258 EST
Comments
Lunation1074
PhaseWaning Gibbous
Age19.93d
Distance
Light Time
(from earth)		368,093 km
s
Elongation°
% Illuminated97.7%
Morning Terminator Colongitude (λ E)100.8°
Evening Terminator Colongitude (λ W)259.2°
Libration in Latitude-4° 59'
Libration in Longitude-3° 16'
Magnitude-12.22
Angular Size8.1"
Altitude62.3°

Virtual Moon Atlas graphic

Stellarium graphic

Cartes du Ciel graphic

I had created a list of possible occultations by time-stepping through VMA figuring as I did it that it was probably an exercise in futility. My feeling was that the Moon, being just past full, would be so bright that it would wash out all but the brightest stars and I only had one of them in my list. My fear was realized when we started observing. Even with a generous FoV around the Moon I saw few stars.

EDTStarMag.D/R
225823 Tau
Merope		4.14D
XZ 48976.98D
2301XZ 49016.99D
2303XZ 49107.76D
2311XZ 4917 D
2313XZ 49057.28D
2320XZ 48928.42D
2321XZ 3321810.43R
233423 Tau
Merope		4.14R
2336XZ 3336410.38D
XZ 3336610.42D
2346XZ 48798.15R
235526 Tau6.47D
0001XZ 48928.42R
0005XZ 49608.09D
0012XZ 48976.98R
0017Atlas3.63D
XZ 49107.76R
 Pleione5.05D
0020XZ 49016.99R
0022XZ49057.28R
0030HL 326.17/10.00D
0031XZ 49846.76D
0033XZ 49585.05D
0054XZ 3336610.42R

We got set up and were observing features in the floor and eastern rim of Mare Crisium and were not attentive to the clock so missed the disappearance of Merope.
Everything was too faint to see until it’s reappearance which Peter picked up at ~2236:15 EST. At 0017:43 Peter marked the disappearance of Atlas. It fell to me to watch Pleione go but it went early. I was observing and we were joking about my way of measuring angular dimensions. I never know what the Fov is in any of Peter’s optics and have taken to relating angular distances to physical objects with which I am familiar. So Pleione started out about 4.5 pea diameters from the limb of the moon. As I checked periodically I made new assessments and when it got down to 2 pea diameters I was having troule recovering it. By 1.5 pea diameters I was no longer even detecting it intermittently and turned the scope back over to Peter who always sees deeper than I do and he couldn’t find it either. The contrast was just too great to see even a Mag. 5 star on the Moon’s bright limb.

There had been a lot of police cars racing around with flashing lights so we didn’t push our luck with curfew to try to see things popping out on the dark limb and left right at 0101 EST.

TargetMars
Constellation Cnc
CategoryPlanet
Time
yyyymmdd.hhmm		20091104.0010 EST
Comments
Object
Class		Classical Planet
Elongation°
Distance
Light Time
(from Earth)		1.1580 AU
m s
Distance
(from Sun)		1.5682 AU
Angular Size8.1"
Magnitude0.4
Central Meridian200.99°
Altitude26° 58'

Stellarium graphic
We had finished talking with a couple of Australians and a Rumanian and went back to naked-eye observing when Peter pointed out something out of place and wondered if it might be Mars or Saturn. He settled on Mars, Saturn being in the morning sky and confirmed it with the telescope. With the Barlow in the planet had a very blue north polar cap and a very red south polar area with the equatorial area looking more like the normal orange. Rather than being the blue ice I saw pictured on Space Weather yesterday this was chromatic aberration with that combination of eyepieces. When the Barlow was removed and a slightly lower magnification eyepiece was used the planet turned into a beautiful orange disk. Seeing that Mars was in Cancer reminded me that it will be occulting M44 this coming weekend so we looked at Mars and M44 in the binoculars. Between the low contrast and hand shake I was having trouble making out M44 but did see a sprinkling of stardust after looking for a while.
[On looking in Stellarium to see the right time for the occultation I found that it occurred 31Oct-1Nov09 so we have missed it. But on 9Nov09 the nearly Last Quarter Moon and Mars will be beneath M44.]
Stellarium graphic
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