20 November 2009

Observing Location	Columbia University
Observational Period	2000-2045 EST
Atmospheric Conditions	Cloud Cover Scattered to Overcast The NOAA automated weather station in Central Park reported that it was clear all night. Temperature 51° F Wind Calm to Light Breeze Humidity Moderate Barometric Pressure 30.08" Hg Rising Feels Like Cool Transparency Poor Seeing II
Instruments	12” Meade Dobsonian 1.25” Plossl 25mm, ~61x estimated
Observing Party	Charlie Ridgway Columbia Grad Students hosts of the public

Target STS-129/ISS Visible Pass Constellation Category Satellite Time yyyymmdd.hhmm 20091120.1802 EST Comments Not Seen I stopped off on the way up to Columbia to try to catch STS-129 doecked at ISS flying past but did not see it between the buildings to the north from my vantage point on the SE corner of Broadway and 57 St.     Starts Max. Alt. Ends H A e b a o v v e e n   s   Time 1803:07 EST 1804:02 EST 1084:02 EST Alt. 10° 13° 13° Az. NNW N N Mag -0.9 This pass was not listed in CalSky.

Target SkyMed 1 Flare Constellation Peg Category Satellite Time yyyymmdd.hhmm 20091120.1832 EST Comments Alt. 66.5° Az. 218.7° SW Mag. 0.4 Surface SAR Panel Observed from the island on the north side of 79 St at Broadway. This didn’t seem to be much of a flare. I caught the satellite falling to the SE and it was as bright as it ever got and didn’t change intensity for a good while until it slowly faded into obscurity.

I attended a lecture on black holes given by one of the grad students who is working on an international project to detect gravity waves. He has an accent that sounds Russian to me and it seemed strange hearing him make jokes that I am used to hearing with an American or maybe British English accent.

Target The Pleiades, M45 Constellation Tau Category Ocl Time yyyymmdd.hhmm 20091120.2015 EST Comments I couldn’t get near the big scope that was on Jupiter which is what I wanted to see with an Io shadow transit in progress so I settled for the Pleiades in a 12” Dob out on the roof. The magnification was too much to show the cluster off well. I think I saw three bright stars at the field stop and some fainter stars scattered in the center of the field.

The clouds were getting thick and they had stopped observing with te big scope after I got on line for it and they were having drive problems with the small MCT and never managed to get it pointed at anything so I left early. It didn’t seem like the kind of night Peter would be schlepping a scope into TotL and when I got to Broadway and 86 St I couldn’t see any stars at all so I just headed home.

19 November 2009

Reading more in Darwin last night I came across some information on the speed of rotation of the Earth at various longitudes and decided to graph this. I had trouble finding a data source but eventually came up with a scanned copy of Physical Geography by Arnold Guyot (© 1875) from the Maryland College Library (thank you Google). The data is somewhat out of date but it does show how the circumference changes with latitude and the oblateness of the Earth. Rotational speed was calculated by dividing the listed circumference by 24 hours.

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I am playing the coverage of the STS-129 first spacewalk in the background and there does not seem to be anywhere near the amount of minute-by-minute direction being given by NASA Mission Control that I have observed before. Most of the communications today are between the space-walkers and the astronauts in Atlantis.

I checked visible passes and there are three dual passes after separation but all of them are during daylight. The only one I would have a chance of would be the 1818 EST pass on 25Nov09 and only then if I can find Jupiter which it will be flying past at a separation of 0.638°.

Wednesday, 25Nov09
		ISS	STS-129
Appears	Time	1642:35 EST	1643:16 EST
	Alt.	horizond>	horizon
	Az.	312.6° NW	312.5 NW
	Mag.	0.2	3.2
Culminates	Time	1647:15 EST	1647:58 EST
	Alt.	24.8°	25.1°
	Az.	25.69deg; NNE	26.0° NNE
	Mag.	-3.2	-0.2
Disappears	Time	1651:28 EST	1652:09 EST
	Alt.	2.0°	2.1°
	Az.	97.0 E	97.3° E
	Mag.	-1.2	1.8
Comments	Sunset 1831 EST

Wednesday , 25Nov09
		ISS	STS-129
Appears	Time	1817:39 EST	1818:22 EST
	Alt.	horizon	horizon
	Az.	299.3° WNW	299.2° WNW
	Mag.	1.0	4.0
Max. Alt.	Time	1822:24 EST	1823:08 EST
	Alt.	34.1°	33.6°
	Az.	222.7° SW	222.8° SW
	Mag.	-2.6	0.5
Disappears	Time	1822:54 EST	1823:37 EST
	Alt.	31.3°	31.1°
	Az.	198.1° SSW	199.2° SSW
	Mag.	-2.8	0.3
Comments	Sunset 1831 EST

Thursday, 26Nov09
		ISS	STS-129
Appears	Time	1705:19 EST	1706:28 EST
	Alt.	horizon	horizon
	Az.	307.9° NW	307.7°NW
	Mag.	0.4	3.4
Max. Alt.	Time	1710:12 EST	1711:32 EST
	Alt.	64.3°	66.3°
	Az.	34.5° NE	34.7° NE
	Mag.	-4.5	-1.5
Disappears	Time	1714:38 EST	1715:10 EST
	Alt.	2.0°	2.2°
	Az.	120.5° ESE	121.1° ESE
	Mag.	-1.1	1.9
Comments	Sunset: 1831 EST

17 November 2009

Observing Location	CSP The police stopped by at 0230 EST to chase me out of the park. I can’t be sure but it may have been because the officer was chauffeuring the sergeant and had to go by the book. Fortunately all they did was chase me out of the park because when I changed out of my shorts before heading out I forgot to take my ID out of the cargo pocket.
Observational Period	0045-00230 EST
Atmospheric Conditions	Cloud Cover Scattered Clouds Temperature 48° F Wind alternating between Gentle Breeze and Moderate Breeze Humidity Moderate Barometric Pressure 30.16" Hg Feels Like Cold Transparency Fair Seeing
Instruments	Naked-eye - Charlie
Observing Party	Charlie Ridgway

2207 EST 16Nov09

Mars Rises

0045 EST

• Aur is high overhead. I can see all three of The Kids
• Gem and Ori are below Aur, Gem slightly higher. I can see the Foot stars of Castor and all three of the Sword stars of Ori.
• Cnc is only notable because Mars is there. It is a little higher than CMa to its south. I eventually saw the body stars of CMa but not the head.
• CMi is half way between CMi and Gem.
• Leo is only remarkable by Regulus and β Leo which are ~10°-15° above the local horizon in the ENE.
• Cas is ~45° up in the NW sitting on her head
• Perseus hs high overhead opposite Aur. I saw a chain of three stars coming off of Mirfac (δ Per, ε Per, and ζ Per) that ended in a wide naked-eye double of ~0.5° separation (ζ Per and ο Per).
• M45 was farther on at the end of the chain and lower down Aldeberan. I made out the large V of The Hyades.

Target Mars Constellation Cnc Category Planet Time yyyymmdd.hhmm 20091117.0045 EST Comments Object Class Classical Planet Elongation ° Distance Light Time (from Earth) 1.05525275 AU m s Distance (from Sun) 1.52 AU Angular Size 8.9" Illuminated 89.5% Magnitude 0.32 Central Meridian 72.64° Altitude 30° Meridian graphic

Target Leonids Meteors Constellation Category Meteors Time yyyymmdd.hhmm 20091117.0045 EST Comments Stellarium graphic This morning was the peak of the Leonids meteor shower which is active from through. The Taurids meteors are also active from through. This was supposed to have been a good year for the Leonids because yesterday was New Moon and the Los Angeles Times said we could see up to 30 meteors per hour. They got the “up to” part right but my hourly rate did not anywhere approach their limit. CNN says the best show will be in Asia Time Period Leonids Taurids 0045-0100 0 0 0100-0200 3 0 0200-2030 1 1 The first meteor was seen early in the hour. It was broad, ~6° lon, and bright white. It moved horizontally across the sky to the south through Mon. The second meteor occurred after 0130 when the sky was heavily covered with clouds and was only seen as a flash of light behind the cloud around where CMi should have been. It did not look like the flash of a strobe light from a plane so I am interpreting it as a meteor. The third meteor was falling somewhat vertically through Hya and was ~3° in length and bright white. It occurred toward the close of the hour. The last Leonid was also a vertical meteor falling through Leo. It was short and yellowish. That happened around 0115 EST> The last meteor was a Taurid. It was falling from 1:00 to 7:00 down the back of CMi. It was bright and had a green tinge to it. I concentrated my view to the ESE because that is where the sky was clear without having to look high overhead. By 0130 EST 50%-75% of my sky was covered with cloud and it didn’t look like they were going to go anywhere soon. A small cloud came in from the N and camped out over Leo and grew. Eventually is moved out to the ENE but was followed by cloud filling in from the SW behind me. By 0215 EST it was mostly clear but my shoulders and neck were sore from the cold and looking up and I decided to leave after spotting Saturn. I never spotted Saturn but the police sealed my resolve.

0214 EST

Saturn Rises

Target Saturn Constellation Vir Category Planet Time yyyymmdd.hhmm 20091117.0114 EST Comments Object Class Classical Planet Elongation ° Distance Light Time (from Earth) 10.0200518 AU h m Distance (from Sun) 10.017 AU Angular Size 16.8" Ring Angular Size 38.6" Ring Inclination ° Magnitude 1.32 Altitude 0° Central Meridian System III 299.30° Stellarium graphic If Saturn rose, and I have to assume that it did, it did so into clouds and haze and was invisible to me. I wouldn’t have been able to detect it, but in the graphic the rings have opened up considerably since I last saw Saturn here on 9Nov09.

0509 EST

Astronomical Twilight begins

0538 EST

Venus Rises

0542 EST

Astronomical Twilight ends
Nautical Twilight begins

0615 EST

Nautical Twilight ends
Civil Twilight begins

0645 EST

Civil Twilight ends
Sunrise

0748 EST

Moon rises

I took a couple of azimuth readings to see how different my compass is from the reality of things.

EST	Target	Az.	Compass
0045	Mars	89° 23’	060°
0230	Sirius	172° 47’	138°

Compass	060	138
Deviation subtract westerly	?	?
Magnetic	060	138
Variation subtract westerly	13.5	13.5
True	046.5°	124.5°
Deviation = deflection of the compass needle due to local ferrous material Variation = generalized deflection of the compass needle due to anomalies in the magnetic field of the earth

Even after adding in variation to my readings I can’t make them come anywhere close to the true azimuth as shown in Carted du Ciel.

I should have taken a reading on Polaris as well.

16 November 2009

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Another thread of the mystery of the tides unravels.

In the Equilibrium Theory of Tides chapter of The Tides and Kindred Phenomena in the Solar System George Howard Darwin says:

Thus far we have supposed the moon exists alone, but the sun also acts on the ocean according to similar laws, although with less intensity. We must now consider how the relative strengths of the actions of the two bodies are to be determined. It was indicated in Chapter V. that tide-generating force varies inversely as the cube of the distance from the earth of the tide-generating body. The force of gravity varies inversely as the square of the distance, so that, as we change the distance of the attracting body, tidal force varies with much greater rapidity than does the direct gravitational attraction. Thus if the moon stood at half her present distance from the earth, her tide generating force would be 8 times as great, whereas her direct attraction would only be multiplied 4 times. It is obvious that if the moon were twice as heavy as in reality, her tide-generating force would be doubled; and if she were half as heavy it would be halved. Hence we conclude that tide-generating force varies directly as the mass of the tide-generating body, and inversely as the cube of the distance.

The application of this law enables us to compare the sun’s tidal force with that of the moon. The sun is 25,500,000 times as heavy as the moon, so that, on the score of mass, the solar tidal force would be 25½ million times greater than that of the moon. But the sun is 389 times as distant as the moon. And since the cube of 389 is about 59 millions, the solar tidal force should be 59 million times weaker than that of the moon, on the score of distance.

We have, then, a force which is 25½ million times stronger on account of the sun’s greater weight and 59 million times weaker on account of his greater distance; it follows that the sun’s tide-generating force is 25½ - 59ths, or a little less than half of that of the moon.

In the previous chapter he says that as the tide comes in the weight of all that water will depress the coastline in relation to its stiffness, soils being depressed to a greater extent than solid rock. This will make the tide appear to rise to a greater extent than it actually does when compared to the height of the geoid.

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Neither Heavens-Above nor CalSky are showing any dial STS-129 and ISS visible passes, or even single visible passes, before Atlantis docks at ISS tomorrow.

Friday, 13 November 2009

STS-129 is currently scheduled for launch on 16Nov09 at 1428 EST. It probably will not be visible as it flys past NYC. It looks like the only chance of seeing it fly overhead in tandem with ISS will occur on 17Nov09 sometime before 1655 EST and that will be a slim chance since it is still Civil Twilignt and ISS will only be Mag. -0.8.

12 November 1009

"You know," said Arthur. it's at times like this, when I'm trapped in a Volgon airlock with a man from Betelgeuse, and about to die of asphyxiation in deep space that I really wish I'd listened to what my mother told me when I was young." "Why, what did she tell you?" "I don't know, I didn't listen." Arthur Dent & Ford Prefect Hitchhiker's Guide to the Galaxy Douglas Adams

10 November 2009

I was searching for software to illustrate position angles and came across a program that creates a Moon calendar so am going to start including it at the beginning of each month.

It has always been a mystery to me how the Moon can attract water on the side of the Earth that is farthest away from it. Darwin has solved that part of the tides mystery for me -- I think.

He talks a lot about centrifugal force and centripetal force. If I follow what he is saying then

The Earth and Moon are at equilibrium at each of their centers. The Earth is 60 Earth radii from the center of the Moon so centrifugal and centripetal force ate at equilibrium there. But since the surface of the Earth facing towards the Moon is closer to the Moon by one Earth radii then the pull of the Moon’s gravity is greater there than it is at the center of the Earth and causes a bulge in the water or a high tide. On the other side surface is one Earth radii farther from the Moon than it is at the center so the attraction of the Moon is less and that allows centrifugal force to build up a bulge of water on that side of the Earth as well.

Then again, I may not understand where e is going at all.