Carpe Noctem - Seize the Night!

Image credit: NASA - The image of Sirius A and Sirius B taken by Hubble Space Telescope. The white dwarf can be seen to the lower left

CANIS MAJOR

I'm a poor underdog,
But to-night I will bark
With the great Overdog
That romps through the dark.

Robert Frost, 1928

Quick News

Water identified in extrasolar planet atmosphere. (Lowell Observatory press release) Lowell Observatory astronomer Travis Barman has found strong evidence for water absorption in the atmosphere of transiting planet HD209458b The identification reported here takes advantage of the fact that HD209458b, as seen from Earth, passes directly in front of its star every three and half days. As a planet passes in front of a star, its atmosphere blocks a different amount of the starlight at different wavelengths. In particular, absorption by water in the atmosphere of a giant planet makes the planet appear larger across a specific part of the infrared spectrum compared to wavelengths in the visible spectrum.

HD 209458 b is an extrasolar planet that orbits the Sun-like star HD 209458 in the constellation Pegasus, some 150 light-years from Earth's solar system. HD 209458 is an 8th magnitude star, visible from Earth with binoculars. The radius of the planet's orbit is one eighth the radius of Mercury's orbit. This small radius results in a year that is 3.5 Earth days long and an estimated surface temperature of about 1000 degrees Celsius or around 1800 degrees Fahrenheit. Its mass is 220 times that of Earth's (0.69 Jupiter masses), which indicates that it is probably a gas giant.

HD209458b is a world well-known among planet hunters. In 1999, it became the first planet to be directly observed around a normal star outside our solar system and, a few years later, was the first exoplanet confirmed to have oxygen and carbon in its atmosphere.

Retrograde and Direct motion

Most planets rotate (spin on their axis) in the direct sense: they spin in the same direction as they orbit the Sun. Which is to say their north rotational pole and north orbital pole point in similar directions, more or less in the direction of the Solar north pole. If you were outside our solar system looking down the sun and most of the planets would appear to rotate counter-clockwise or anti-clockwise as you prefer. The exceptions to this rule are Venus and Uranus.

Venus is nearly always described as having its axis at 3 degrees and a rotation of -243 days, rather than 177 degrees and +243 days, in essence it is rotating normally but flipped completely upside down.

Uranus on the other hand lays on its side with its N-S axis parallel to the orbital plane instead of perpendicular. Uranus has an axial tilt of 82 degrees and a negative rotation of -17 hours, or, equivalently, of having an axis tilted at 98 degrees and a positive rotation. Since current speculation is that Uranus started off with a typical direct orientation and was knocked on its side by a large impact early in its history, it is most commonly described as having the higher axial tilt and positive rotation.

When we observe the sky, the Sun, Moon, and stars appear to move from east to west because of the rotation of the Earth (diurnal motion)is relatively quick, a day. This equates to the daily rising and setting of the Sun, Moon, constellations and planets. However if we study the position of the planets, relative to the background stars, over time they appear to travel, pause, reverse direction, pause, and then resume their direct, or eastward, motion around the Sun. It is this peculiar motion that baffled our astronomical ancestors and probably why the Greeks called our fellow solar system brethren 'planetes' or wanderers.

When looking inward, to Venus or Mercury, the motion we see is the direct orbit of those planets around the Sun. Their orbits are faster than ours and closer to the Sun so when we see them moving away from the Sun, pause, return toward the Sun, vanish, and then appear on the other side we observing their direct orbits around the Sun. The pausing and change of direction here are artifacts of our position in the same plane as much like sitting on the ground watching a child on a merry-go-round. The child is moving in a circular orbit around the center of the merry-go-round not shifting back and forth as the same-plane-view might delude us into thinking. This interior position allows Mercury and Venus to appear as both morning and evening 'stars' in the sky much the same way the child appears to the left or right of the center of the merry-go-round. For a real life study just observe Mercury.

On the other hand the superior planets, those with orbits outside of Earth's, have a longer orbital period. Our orbit period is faster which changes our line of sight. While we are behind in our orbits the planet we are catching up to appears to move eastward against the background stars but as we get closer to conjunction the planet appears to slowdown, stop, and turn moving westward. Once we pass conjunction and pull 'ahead' of the other planet it again appears to pause and reverse following us in a direct or eastward orbit.

Again, trotting down to the playground would be a good way to experiment. This time you need to take your place on the outside of the merry-go-round and carefully observe someone in the distance rolling beyond you in an orbit around the merry-go-round and watch their progress against background objects. But lacking a near by play ground here are some illustrations that might help.

Credit & Copyright: Tunc Tezel (Astronomy Picture of the Day - Dec 16, 2003) Mars is the bright object illustrating retrogradation and the fainter object in the background is Uranus in its direct motion.

Animation of Mars 2003 credit: NASA

For example Saturn has been slowly moving westward away from Regulus (in Leo) for the past few months and on the 20th of this month will appear to pause, turn and return on its direct (eastward) motion across the sky where as Jupiter has just begun it's retrograde motion.

Planets

• Venus - Mag -3.9 in Taurus the bull is making several fantastic pairings for those of you who are looking for some great photo opps. Right now she is between the Pleiades and the Hyades.
• Saturn - Mag 0.3 in Leo has just finished its retrograde motion and is now moving in its direct (eastward) motion. Big, bright and beautiful and an easy catch in binoculars or small telescope.
• Jupiter - Mag -2.2 in Ophiuchus the serpent bearer is getting ready to start its retrograde motion appearing to move a little bit westward against the background stars.

• Neptune - Mag 7.9 in Capricorn the sea goat
• Mars - Mag 1.1 in Aquarius the water bearer approaching....
• Uranus - Mag 5.9 also in Aquarius. Small telescope will be needed as you catch these three on the eastern horizon just before sunrise.
  
  
  
• Mercury - Mag -0.4 in Pisces the fish. Good morning viewing for those of you in the South much harder the further north you travel.

Constellations

Image Credit: Phobos Group website

Canis Major, Canis Minor - The greater and lesser dogs
Introduced by: Canis Major was in Ptolemy's list of 48 constellations but has been apart of astronomical lore since before the Egyptian.
Best known stars: Sirius (binary star A and B)is Greek for scorching.
The ancient Egyptians based their calendar on the heliacal rising of Sirius and devised a method of telling the time at night based on the heliacal risings of 36 stars called decan stars (one for each 10 degree segment of the 360 degree circle of the zodiac/calendar). For the Egyptians this marked the annual rising of the Nile and the 'dog' days of summer. You can see an animated illustration of Sirius' heliacal rising at the Stanford Solar Center's website (animation)

Roman myth refers to Canis Major as Custos Europae, the dog guarding Europa but who fails to prevent her abduction by Jupiter in the form of a bull.

He is also Laelaps, Actaeon's hound

More commonly Canis Major and Minor are Orion's hunting dogs, pursuing Lepus the hare or Taurus the Bull

Viewing

Binoculars - using the Free Mag 7 star atlas: Chart 9
M41 open cluster in Canis Major discovered, and documented, long before the advent of the telescope in 325 B.C. Aristotle described M41 as a cloudy spot.
100 stars into an area of about 25 light years across with several orange or red giants including the one towards the center of the cluster.
M47 open cluster in Puppis and this one gets better as you move from binos to telescopes! With binos it is a hazy blotch with a few sprinkles of bright light but with a telescope you can pick up 30 blue-white stars from 6-12th mag. The western most corner of the area around M47 is home to a reddish orange variable star KQ Puppis which sticks out as distinctly red in this blue-white group.
M46 open cluster in Puppis over 3X further away than M47; a good study in how distance 'appears' to our eyes. This cluster has a more uniform, denser cluster of faint stars. Sitting between Earth and M46 is NGC 2438 a planetary nebula that glows faintly at 10th mag. After you get settled in M46 use your averted vision to catch 2438 and then power-up to see how much detail you can see.
M93 open cluster in Puppis. Smaller than 46 and 47, 93 will show as half a dozen stars mixed in a dim glow for binoculars but a telescope will pick up 30 faint stars that seem to chain up in various curves and arcs.
M50 open cluster in Monoceros is fairly easy to find because it is all alone. M50 can be viewed as a faint hazy patch in dark skies and each 'bump' up in power and aperture reveals more starts. With an 8" scope and decent skies look for a triangle of stars that mark the center of the cluster

Telescope -
Maps 103 and 102 Taki's chart
NGC 2383 and 2384 the "Double Dog" clusters- 8.4 mag pair of OC in CMajor, due east of NGC 2287 (M41) just about 15 degrees.
Slide NW about 5 degrees to a 4.2 mag OC discovered by Caroline Herschel, C58 or NGC 2360

Challenge -
NGC 2207, 12.3 mag pair of face on spirals playing tug of war
NGC 2283 12.4 mag spiral galaxy just below alpha CMaj
NGC 2359 "The Duck" or "Thor's Helmet" emission nebula NNE part of CMaj

College Salute -
Start with NGC 2362 and open cluster around Tau CMaj just NE of Delta CMaj (Wezen, where the dog's legs join or the tail joins the body as you prefer). The cluster contains 40 members and is one of the youngest known star clusters. Now moving to the NNE corner of the cluster we are looking for the Big Dawg of the Big Dog; UW Canis Majoris (not to be confused with the UW Huskies). A mag 4.9 super giant spectroscopic binary and one of the most luminous and massive stars in our galaxy. The two stars are separated by 27 million kilometers and revolve around each other in less than four and a half days! (Herschel 400 object)

Sun

sunspots

The Moon

Lunar Phase Pro

Our beautiful lunar photos are courtesy of Frank Barrett at celestialwonders.com
I highly recommend his site for lunar phase photos. You can zoom in to his images for more detail.

Click for annotated map
Online Lunar navigation map.

Object	Latitude	Longitude	Comments
1. Plato	51.6	-9.4	(Lunar 100 and AL Lunar list)Greek philosopher c.428-c.347 B.C.
2. Valles Alpes	48.5	3.2	(Lunar 100 and AL Lunar list)
3. Cassini A/B (to the right of the number)	40.5	4.8	(AL Lunar list) Giovanni Domenico; Italian-French astronomer (1625-1712); Jacques J.; French astronomer (1677-1756)
4. The 3 Greeks (largest to smallest):Archimedes, Aristillus, Autolycus	29.7	-4	(Lunar 100 and AL Lunar list)Archimedes:Greek physicist, mathematician (c. 287-212 B.C.), Aristillus:Greek astronomer (fl. c. 280 B.C.), Autolycus of Pitane; Greek astronomer (fl. c. 310 B.C.).
5. Aristoteles w/Mitchell and Eudoxus	50.2	17.4	(Lunar 100 and AL Lunar list)Aristoteles:Greek astronomer, philosopher (383-322 B.C.), Mitchell: American astronomer (1818-1889), Eudoxus:Greek astronomer (c. 408-355 B.C.)
6. Posidonius	31.8	29.9	(Lunar 100 and AL Lunar list)Of Apamea; Greek geographer (135(?)-51(?) B.C.)
7. Serpentine Ridge (Dorsum Smirnov and Dorsum Lister)	20.3	23.8	(Lunar 100)Martin Lister; British stratigrapher, zoologist (1639-1712), Sergei Sergeevich Smirnov; Soviet Earth scientist (1895-1947
8. Lakes District			See Show #28
9. The Waterfall: Ptolemaeus, Alphonsus, Arzachel	-9.3	-1.9	(Lunar 100 and AL Lunar list)Ptolemaeus:Ptolemy, Greek astrononer, mathematician, geographer (c. A.D. 87-150, Alphonsus Alfonso X (El Sabio); Spanish astronomer (1221-1284), Al Zarkala (Arzachel); Spanish-Arabic astronomer (c. 1028-1087)
10. Rupes Recta - The Straight Wall	-22.1	-7.8	(Lunar 100 and AL Lunar list)
11. Miller, Nasireddin, Huggins	-39.3	0.8	William Allen Miller; British chemist (1817-1870), Nasir-Al-Din (Mohammed Ibn Hassan); Persian astronomer (1201-1274), Sir William Huggins; British astronomer (1824-1910)
12. Tycho	-43.4	-11.1	(Lunar 100 and AL Lunar list) Tycho Brahe; Danish astronomer (1546-1601)
AAGG Favorite: Palus Somni and Crater Proclus (coordinates)	16.1	46.8	(Lunar 100 and AL Lunar list) Marsh of Sleep, Greek mathematician, astronomer, philosopher (410-485)

Remember latitudes that are negative (-) are South and longitudes that are negative (-) are West!

Comets

Comets for the Month.

Check out the Sky Hound site.

"One touch of nature makes the whole world kin"
-- Shakespeare

Email us at astronomyagogo@gmail.com or leave a note in our show notes at www.astronomy.libsyn.com
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Carpe Noctem - Seize the Night!

Image courtesy of Dr. Mark Showalter

Moons and Rings Teleconference

Download the Powerpoint presentation!

The Night Sky Network (NSN)is a nationwide (USA)collection of astronomy clubs delivering NASA and JPL inspired science and mission related information to the general public. The Night Sky Network creates kits and outreach tools specifically for amateur astronomer and the general public. To find a NSN club near you visit their website: nighsky.jpl.nasa.gov

Special thanks to the Night Sky Network, our NSN host Marni Berendsen, and Dr. Mark Showalter.

Woodland Hills Camera and Telescope is offering FREE web hosting on our servers for you or your organization's website. In order to promote the hobbies of Astronomy, Astrophotography, Photography, Birding or generally any topic that is of interest to our customer base, Woodland Hills Camera and Telescope is offering Hosting Grants.

Carpe Noctem - Seize the Night! Week of Oct. 16, 2006

ARCTURUS IN AUTUMN

Oh, then I knew at last that my own autumn was upon me,
I felt it in my blood,
Restless as dwindling streams that still remember
The music of their flood. There in the thickening dark a wind-bent tree above me
Loosed its last leaves in flight--
I saw you sink and vanish, pitiless Arcturus,
You will not stay to share our lengthening night.

Sara Teasdale, 1926 (TOAOAL-II, pg. 1245)

Listener Question

Dan wanted directions for finding the Andromeda galaxy! I like to start with Alpheratz (al-FEE-rahts) the corner star in the great square of Pegasus shared by both constellations. This is the corner closes to Perseus and Cassiopeia. There is a long slender "V" with the brighter of the two track further away from Cassiopeia. If you start at Alpheratz, jump two stars down the brighter track to Mirach. The jump towards Cassiopeia two stars and stop. M31, the Andromeda galaxy, is just a nudge to the east. You will have 3 galaxies right there, M31, M32 and M110.

If you are having problems with faint stars another way to find M31 is to follow Cassiopeia. Start by finding Cassiopeia, if you draw a "W" on paper from left to right you make 4 lines resulting in 2 "V"s (no vendetta here)the second "V" points straight to Mirach then just back up a quarter of the way and shift east. M31 from the city looks nothing like the pictures she huge smear in the telescope with a very bright center. Give yourself time and dark skies to improve her view.

photo courtesy of: NASA Mariner 10

Feature Attraction - Mercury

Historical/Myological Facts

• Mercury was the Roman god of trade and commerce, in the same vein as Hermes of the Greeks, the messenger
• In India Mercury was called Buddha
• Mayans charted the motion of the planet Mercury as well; records of their detailed observations are found in the Dresden Codex. These include the appearance of Mercury as a morning star in 733 B.C. and as an evening star in 727. The Mayans also calculated that Mercury would rise and set in the same place in the sky every 2,200 days
• Translations from surviving cuneiform tablets reveal that Mercury was designated by many names, including that transcribed by archaeologists as MulUDU.IDIM.GU.UD. Mercury was often associated with Nabu, or Ninurta, the god of water and writing. Later, in Akkadian, it became known as Shikhtu, meaning "jumpy"
• For the Egyptian Mercury was called Thoth, the great measurer - a divinity associated with knowledge, and the inventor of speech, writing, and arithmetic
• For the northern ancestors, Mercury was named Odin, the supreme god. Often referred to as the god of wisdom, magic, and war, and the inventor of runes, his name means "inspired one". Odin was worshiped throughout northern Europe (including Britain), wherever the Vikings and other Nordic peoples settled. Odin was also known as Woden, and it is from this form that the English word for Wednesday is derived

  450 B.C. the Greeks started studying the motions of the planets and using geometry to measure the size of the Earth, Sun and Moon. Mercury was known by two different names, associated with its evening and morning appearances. These were Apollo (god of truth, the arts, archery, plagues, and divination) and Hermes (god of writing and messenger to the other gods).

Fast Facts!

• Mercury is the nearest planet to the sun. It has the most extreme contrast in temperature between day (430°C) and night (-180°C) in the solar system. Daytime temperatures are high enough to melt zinc and tin.
• BUT! Mercury is not the hottest planet, Venus is due to its heat trapping atmosphere
• Mercury's axis of rotation is oriented nearly perpendicular to the planet's orbit (axial tilt=0), so that in the polar regions sunlight strikes the surface at a constant grazing angle. The interiors of large craters at the poles are permanently shadowed and remain perpetually cold, below -212ºC (-350° F). Amazingly, radar observations of Mercury's north pole by Arecebo(a region not mapped by Mariner 10) show evidence of water ice in the protected shadows of some craters.
• Mercury's orbit is highly eccentric; at perihelion it is only 46 million km from the Sun but at aphelion it is 70 million. 
• Pluto has the most elongated orbit, two-thirds further from the Sun at aphelion than at perihelion.
• Mercury has virtually no atmosphere, meaning life as we know it is impossible.
• Mercury rotates three times for every two orbits of the sun
• This fact and the high eccentricity of Mercury's orbit would produce very strange effects for an observer on Mercury's surface. At some longitudes the observer would see the Sun rise and then gradually increase in apparent size as it slowly moved toward the zenith. At that point the Sun would stop, briefly reverse course, and stop again before resuming its path toward the horizon and decreasing in apparent size. All the while the stars would be moving three times faster across the sky. Observers at other points on Mercury's surface would see different but equally bizarre motions.
• Mercury is the second densest major body in the solar system, after Earth. Actually Earth's density is due in part to gravitational compression; if not for this, Mercury would be denser than Earth. This indicates that Mercury's dense iron core is relatively larger than Earth's, probably comprising the majority of the planet. Mercury therefore has only a relatively thin silicate mantle and crust.
• Only one spacecraft has been to mercury, Mariner 10, passing three times in 1974-75.
• However NASA's Messenger is on the way, launched in August 2004, and will fly by three times and then enter mercury orbit in March 2011. Then in 2012, ESA/ISAS's BepiColombo will be launched, also into mercurian orbit.
• Because of mercury's proximity to the sun, it cannot safely be photographed by the Hubble Space Telescope.
• Mercurian atmosphere is thin enough to be described as an exosphere, meaning the constituent atoms never collide. The identified elements in the exosphere are sodium, potassium, hydrogen, oxygen and neon. Ions and high frequency electromagnetic radiation from the sun are responsible for dislodging the atoms in the exosphere.
• Mass (kg) 3.302x1023
• Diameter is 4,880 kilometers (3,032 miles) (32% that of Earth) 2nd smallest of the classical planets now the smallest
• Perihelion (km) 46.00x106
• Aphelion (km) 69.82x106
• Length of day (hours) 4222.6

Why care about Mercury?

It offers a chance to examine another outcome of the processes that also produced Earth, Venus and Mars.

Learning how Mercury ended up the densest planet (after correcting for internal pressures) will tell us much about planetary formation.

Discovering how Mercury has sustained a magnetic field while larger bodies either have lost an earlier field (as Mars did) or have no present field and no record of a past field (Venus) will help us to understand magnetic field generation in our own planet.

Mercury also has the thinnest atmosphere among all the terrestrial planets and an incredibly wide temperature range. In fact, temperatures vary from nearly the highest in the solar system (at the equator) to among the coldest (in the permanently shadowed areas where ice deposits seem to lurk). Documenting the nature of Mercury's tenuous and changeable atmosphere and the composition of its mysterious polar deposits - thought by many to consist of water ice - will give us new insight into the volatile materials in the inner solar system.

Transit of Mercury Nov. 8 2006

Viewing the transit safely!
Build a solar filter Sources for Baader film (http://www.baader-planetarium.com/sofifolie/details_e.htm#distributor)

Fun Mercury Tools

Planets

• Mercury - Mag 0.0 in Libra. Mark your calendars for inferior conjunction and visible transit on Nov. 8th!
• Jupiter - Mag -1.6 in Libra. Clearly visible low in the sky just after sunset. Any telescope can reveal its two widest cloud bands and four Galilean satellites.
  
  
  
  images courtesy of: Stellarium software
• Pluto - Mag +14.0 in Ophiuchus
• Uranus - Mag +5.8 in Aquarius Uranus is best seen in a dark moonless sky away from artificial lighting. It may be seen looking like a very faint star to the dark-adapted naked eye that shimmers in and out of visibility just over 1 degree east of Lambda Aquarii. Find the tipped over letter Y of Aquarius, go 4 thumbwidths southeast to find Lambda, and then look pinky nail east.
• Neptune - Mag +7.9 in Capricorn 1 degree north of the +4.3 magnitude star Iota Capricorni

Too close to the sun..

• Mars - Mag +1.6 is at the western end of Virgo. You will have to look hard in the haze of the horizon and it will help to be closer to the equator.
• Venus - Mag -3.8 in Virgo.

• Saturn - Mag +0.6 on the western edge of Leo!

• 1 Ceres +7.9 mag in Piscis Austeralis 18.5 degrees West of Formalhaut
• Eris mag +19 in central Cetus

Constellations

Circinus -Circinus was invented by Lacaille during his stay at the Cape of Good Hope between 1751 and 1752. Latin for compass, is one of the small southern (declination -50 to -60 degrees) constellations. It represents a tool used in drawing maps and as such should not be confused with Pyxis, a constellation associated with a ship's compass.

Pyxis(-Latin for box as in Pyxis Navigatum [lit. Sailor's Box, a compass]) is a minor southern constellation introduced by Nicolas Louis de Lacaille under the name Pyxis Nautica. It is perhaps supposed to represent the compass of Argo Navis but not formally a part of Argo Navis; that is, the stars in it have their own independent Bayer designations (unlike Carina, Puppis and Vela which retained and split among themselves the Bayer designations from Argo).

Vulpecula - (vul-pek-U-lu) the Fox, It was originally known as Vulpecula cum ansere = "the Fox with the Goose" created by Hevelius, but the goose no longer appears on star charts but the name remains in Alpha Vulpeculae is a red giant of spectral class M0 and has apparent magnitude +4.4 the least faint star in this very faint constellation.

However! :-) As faint as this constellation is it has too noteworthy features; "The Coathanger" more formally named Brocchi's Cluster (Collinder 399) and M27, the Dumbbell Nebula, is a large, bright planetary nebula which was discovered by the French astronomer Charles Messier in 1764 as the very first object of its kind. Find them!

Viewing

Naked eye -
NH: Time to get up early! Winter triangle, the Hyades (head of Taurus) and the Winter hexagon
SH: Large and Small Magellanic clouds, 47 Tucanae

Binocular -
NH: Star hop your way to the Andromeda Galaxy.
SH: NGC 362 globular cluster in Tucanae

Telescope -
Comet Swan currently in Canes Venatici. From the city it looks like a faint nebulous globular cluster! I did NOT see this! Aerith.net, Heavens-above.com
Comet C2006 T1 (Levy) currently in Leo. Wait until mid-week for the moon to get out of the way.
M27 - The Dumbell Nebula in Vulpecula
NH: M33 in Triangulum directly opposite Mirach from M31 - and with it NGC 604 and for a real challenge NGC 595, NGC 592 and NGC 588!
SH: Circinus Galaxy - NGC 346
in SMC -find it NGC 2070 - the Tarantula Nebula -find it Southern hemisphere challenge object very low surface brightness Mag 12.9
NGC 5715 9.8 Open Cluster

The Moon

Images created with Lunar Phase Pro

Our beautiful lunar photos are courtesy of Frank Barrett at celestialwonders.com I recommend visiting his site and checking out his lunar phase photos. You can zoom in for more detail.

Remember latitudes that are negative (-) are South and longitudes that are negative (-) are West!

Comets

Comets for the Month.

"One touch of nature makes the whole world kin"
-- Shakespeare

Email us at astronomyagogo@gmail.com or leave a note in our show notes at www.astronomy.libsyn.com
Help us out by leaving a donation in the ol' PayPal hat

Music

Woodland Hills Camera and Telescope is offering FREE web hosting on our servers for you or your organization's website. In order to promote the hobbies of Astronomy, Astrophotography, Photography, Birding or generally any topic that is of interest to our customer base, Woodland Hills Camera and Telescope is offering Hosting Grants.

Direct from the IAU webpage...

"The IAU members gathered at the 2006 General Assembly agreed that a "planet" is defined as a celestial body that (a) is in orbit around the Sun, (b) has sufficient mass for its self-gravity to overcome rigid body forces so that it assumes a hydrostatic equilibrium (nearly round) shape, and (c) has cleared the neighbourhood around its orbit.

This means that the Solar System consists of eight "planets" Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus and Neptune. A new distinct class of objects called "dwarf planets" was also decided. It was agreed that "planets" and "dwarf planets" are two distinct classes of objects. The first members of the "dwarf planet" category are Ceres, Pluto and 2003 UB313 (temporary name). More "dwarf planets" are expected to be announced by the IAU in the coming months and years. Currently a dozen candidate "dwarf planets" are listed on IAU's "dwarf planet" watchlist, which keeps changing as new objects are found and the physics of the existing candidates becomes better known.

The "dwarf planet" Pluto is recognised as an important proto-type of a new class of trans-Neptunian objects. The IAU will set up a process to name these objects.

Below are the planet definition Resolutions that were passed:

RESOLUTIONS
Resolution 5A is the principal definition for the IAU usage of "planet" and related terms.

Resolution 6A creates for IAU usage a new class of objects, for which Pluto is the prototype. The IAU will set up a process to name these objects.

IAU Resolution: Definition of a Planet in the Solar System
Contemporary observations are changing our understanding of planetary systems, and it is important that our nomenclature for objects reflect our current understanding. This applies, in particular, to the designation 'planets'. The word 'planet' originally described 'wanderers' that were known only as moving lights in the sky. Recent discoveries lead us to create a new definition, which we can make using currently available scientific information.

RESOLUTION 5A
The IAU therefore resolves that "planets" and other bodies in our Solar System be defined into three distinct categories in the following way:

(1) A "planet"¹ is a celestial body that (a) is in orbit around the Sun, (b) has sufficient mass for its self-gravity to overcome rigid body forces so that it assumes a hydrostatic equilibrium (nearly round) shape, and (c) has cleared the neighbourhood around its orbit.

(2) A "dwarf planet" is a celestial body that (a) is in orbit around the Sun, (b) has sufficient mass for its self-gravity to overcome rigid body forces so that it assumes a hydrostatic equilibrium (nearly round) shape² , (c) has not cleared the neighbourhood around its orbit, and (d) is not a satellite.

(3) All other objects³ except satellites orbiting the Sun shall be referred to collectively as "Small Solar-System Bodies".

¹The eight planets are: Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus, and Neptune.
²An IAU process will be established to assign borderline objects into either dwarf planet and other categories.
³These currently include most of the Solar System asteroids, most Trans-Neptunian Objects (TNOs), comets, and other small bodies.

IAU Resolution: Pluto

RESOLUTION 6A
The IAU further resolves:

Pluto is a "dwarf planet" by the above definition and is recognized as the prototype of a new category of trans-Neptunian objects.1

Carpe Noctem - Seize the Night!

Image credit: Stellarium Software

The lights from the parlour and kitchen shone out
Through the blinds and the windows and bars;
And high overhead and all moving about,
There were thousands of millions of stars.
There ne'er were such thousands of leaves on a tree
Nor of people in church or the Park,
As the crowds of the stars that looked down upon me,
And that glittered and winked in the dark.

The Dog, and the Plough, and the Hunter, and all,
And the star of the sailor, and Mars,
These shone in the sky, and the pail by the wall
Would be half full of water and stars.
They saw me at last, and they chased me with cries,
And they soon had me packed into bed;
But the glory kept shining and bright in my eyes,
And the stars going round in my head. 

AAGG Recall and general confusion

News from the IAU General Meeting in Prague

"The part of "IAU Resolution 5 for GA-XXVI" that describes the planet definition, states "A planet is a celestial body that (a) has sufficient mass for its self-gravity to overcome rigid body forces so that it assumes a hydrostatic equilibrium (nearly round) shape, and (b) is in orbit around a star, and is neither a star nor a satellite of a planet."

"According to the new draft definition, two conditions must be satisfied for an object to be called a "planet." First, the object must be in orbit around a star, while not being itself a star. Second, the object must be large enough (or more technically correct, massive enough) for its own gravity to pull it into a nearly spherical shape."

"A secondary object satisfying these conditions is also designated a planet if the system barycentre resides outside the primary. Secondary objects not satisfying these criteria are "satellites"."

"The IAU draft Resolution also defines a new category of planet for official use: "pluton". Plutons are distinguished from classical planets in that they reside in orbits around the Sun that take longer than 200 years to complete (i.e. they orbit beyond Neptune). Plutons typically have orbits that are highly tilted with respect to the classical planets (technically referred to as a large orbital inclination). Plutons also typically have orbits that are far from being perfectly circular (technically referred to as having a large orbital eccentricity). All of these distinguishing characteristics for plutons are scientifically interesting in that they suggest a different origin from the classical planets."

For a little Pluton entertainment check out Slacker Astronomy at slackerastronomy.org

Planets

Photo credit: Stellarium Software

Evening Planets
• Mars - Mag +1.8 is between the back legs of Leo the Lion. You will have to look hard in the haze of the horizon and it will help to be closer to the equator.
• Jupiter - Mag -1.8 in Libra. Clearly visible high in the sky just after sunset. Any telescope can reveal its two widest cloud bands and four Galilean satellites.
  Listener Kevin recommended a piece of free software that I now have on all my computers Jupiter 2 (Thanks Kevin!).
  
• Uranus - Mag +5.9 in Aquarius Uranus is best seen in a dark moonless sky away from artificial lighting. It may be seen looking like a very faint star to the dark-adapted naked eye that shimmers in and out of visibility a thumbwidth east of Lambda Aquarii. Find the tipped over letter Y of Aquarius, go 4 thumbwidths southeast to find Lambda, and then look one thumbwidth east using binoculars..
• Neptune - Mag +7.9 in Capricorn 1 degree north of the +4.3 magnitude star Iota Capricorni
  
• Pluto Mag +13.9 in Serpens Cauda

  Morning Planets

• Venus - Mag -3.62 The brightest morning planet visible. To the ESE the bright star Sirius is rising with Venus in the morning.
• Mercury - Mag -1.1 between the Sun and Venus (3.5 degrees East of Venus)
• Saturn - Mag +0.4 In Cancer and on the eastern horizon just after sunset and favored for those of you close to the equator.

More "Scale of the Solar System"

Viewing

Found a great site for NGC images go to the Digitized Sky Survey Site (DSS) and check out the images. I like the fact that you can see a page worth of thumbprints and then open the one you are looking for.

Naked eye and Binoculars The real show is for naked eyes in the morning (okay maybe a little bino help). Check out the Moon, Venus, Mercury and Saturn.
Something for evening viewing? Check out variable star Chi Cygni. It is a long period variabel star along the long neck of Cygnus the Swan and is right now at mag 4.0 (range 5.0-13.4)

Photo in the infrared by Maurice Gavin

Telescope NGC 6864 or M75 globular cluster at 8.6 mag
NGC 7099 or M30 globular cluster at 6.9 mag a very bright
NGC 7089 or M2 globular cluster at 6.6 mag
NGC 6994 or M73 open cluster at 8.3 mag small 4 star cluster
NGC 6981 or M72 globular cluster at 9.2 mag

Challenge Object NGC 7293 the Helix Nebula a planetary nebula at 7.3 mag
NGC 7009 or the Saturn Nebula planetary nebula at 8.0

The Moon

Maps created with Lunar Phase Pro

Lunar photo is courtesy of Frank Barrett at celestialwonders.com I recommend visiting his site and checking out his lunar phase photos. You can zoom in for more detail.

This weekend waning gibbous
New Moon - Aug 23rd 1st Quarter - Sept 1st

Comets for August

News

Grand Rapids Amateaur Astronomical Association (GRAAA) host public nights at the James C. Veen Observatory on the second and last Saturdays of the month (April through October), if the skies are clear. Please call the Starwatch number -- 897-7065 -- for updates and the status of a particular night if the weather conditions are questionable.
Admission for visitors' nights are $3 for Adults, $2 for 17 years and younger, and free for children under 5 years of age.

Music

Woodland Hills Camera and Telescope is offering FREE web hosting on our servers for you or your organization's website. In order to promote the hobbies of Astronomy, Astrophotography, Photography, Birding or generally any topic that is of interest to our customer base, Woodland Hills Camera and Telescope is offering Hosting Grants.

Carpe Noctem - Seize the Night!

Image credit: NASA/JPL/Yale

Spectrographic image of a quasar for Sabrina

"The Music of the Night"

Nighttime sharpens, heightens each sensation
Darkness stirs and wakes imagination
Silently the senses abandon their defenses

Slowly, gently, night unfurls its splendour
Grasp it, sense it, tremulous and tender
Turn your face away from the garish light of day
Turn your face away from cold, unfeeling light
And listen to the music of the night

Close you eyes and surrender to your darkest dreams
Leave all thoughts of the world you knew before
Close your eyes, let your spirit start to soar
And you'll live as you've never lived before

Softly, deftly, music shall caress you
Hear it, feel it, secretly possess you
Open up your mind, let your fantasies unwind
In this darkness which you know you cannot fight
The darkness of the music of the night

Let your mind start a journey through a strange, new world
Leave all thoughts of the world you knew before
Let your soul take you where you long to go
Only then can you belong to me

Floating, falling, sweet intoxication
Touch me, trust me, savour each sensation
Let the dream begin, let your darker side give in
To the harmony which dreams alone can write
The power of the music of the night

You alone can make my song take flight
Help me make the music of the night

music by Andrew Lloyd Webber
lyrics by Charles Hart and Richard Stilgoe
from "The Phantom of the Opera"

Listener Feedback

Once you find them you may, at first, just think "Huh, is that all." but think about it, they are the furthest two gas giants and are, at their closest, 2.57 billion km and 4.3 billion km from Earth respectively. Now just how big and reflective does something have to be to be seen 4.3 billion miles away?

Planets

Evening Planets
• Mars - Mag 1.6 is between the back legs of Leo the Lion and is 12 degrees SW of Denebola. You will have to look hard in the haze of the horizon and be closer to the equator.
• Jupiter - Mag -2.5 in Libra. Clearly visible high in the sky just after sunset, just 2.5 degrees east of Spica. Any telescope can reveal its two widest cloud bands and four Galilean satellites.
  Listener Kevin recommended a piece of free software that I now have on all my computers Jupiter 2 (Thanks Kevin!).
  
• Uranus - Mag. 5.9 in Aquarius Uranus is best seen in a dark moonless sky away from artificial lighting. It may be seen looking like a very faint star to the dark-adapted naked eye that shimmers in and out of visibility a thumbwidth east of Lambda Aquarii. Find the tipped over letter Y of Aquarius, go 4 thumbwidths southeast to find Lambda, and then look one thumbwidth east using binoculars..
• Neptune - Mag. 7.9 in Capricorn 1 degree north of the +4.3 magnitude star Iota Capricorni
  
• Pluto Mag. 14 in Serpens Cauda

  Morning Planets

• Venus - Mag -3.9 The brightest morning planet visible. To the ESE the bright star Sirius is rising with Venus in the morning.
• Mercury - Mag -1.0 between the Sun and Venus (3.5 degrees East of Venus)
• Saturn - 0.1 mag In Cancer and on the eastern horizon just after sunset and favored for those of you close to the equator.

  I know we have some AAGG listeners out there that are wee hours of the morning observers so it would be great if you folks would put your observations in the show note comments!

"The Distance to the Planets by Halves" activity coming soon....

Constellations

Viewing

Naked eye The Perseids between now and the beginning of next week. Wake yourself up early and catch Mercury and Venus and in the next week or two Saturn in the morning sky.

Binocular M22(NGC 6656) the third brightest globular cluster after Omega Centauri and 47 Tucanae and is the closest globular to us. It is 100 ly in diameter and has 100,000 suns.

Telescope Globular cluster in Sanitarium just NW of M22, NGC 6642. Another pair NGC 6522 and NGC 6528

Challenge Object Planetary nebula NGC 6790 in Aquila. Start at delta Aquilae, go 2 degrees South and then a little west (see image)

The Moon

Maps created with Lunar Phase Pro

Lunar photo is courtesy of Frank Barrett at celestialwonders.com I recommend visiting his site and checking out his lunar phase photos. You can zoom in for more detail.

This weekend waning gibbous
Last Quarter - Aug 15th
New Moon - Aug 23rd

Comets for August

Astronomer Activist

The IDA European meeting will take place on 15-16 September in Portsmouth, England, UK

Asia-Pacific Conference, to be held 26-28 October 2006 in Sydney, Australia. The Conference will occur together with the Illuminating Engineering Society of Australia and New Zealand (IESANZ) Annual Convention, with the theme "Our Lighting Future."

You might also be interested in a recent report from California Connected entitled "In Search of Darkness." There is a great little video about the US National Park System and their dark sky data collection. Watch it!

News

Jupiter spots recap and pictures

Mars Attacks! Phil Plait's Bad Astronomy blog says it best....

Speaking of Mars, the Science Cafe (Orange County Chapter) is hosting a "Wine, Dinner, and Mars" event in September so if you are planning to be anywhere near Anaheim CA September 19th go to their website and check out their event. On Friday, August 18, 8-10 PM, the UC-Irvine Observatory is hosting an open "Visitor Night" to see the planet Jupiter, the Perseids, and feature a slide show called, "The History of the Solar System."

Music

I'd give you the moon - Jake Coco

Woodland Hills Camera and Telescope is offering FREE web hosting on our servers for you or your organization's website. In order to promote the hobbies of Astronomy, Astrophotography, Photography, Birding or generally any topic that is of interest to our customer base, Woodland Hills Camera and Telescope is offering Hosting Grants.

Carpe Noctem - Seize the Night!

"Birth of Venus"
Sandro Botticelli

Thank you Pamela!

Pamela came up to visit and we had a blast! I will post her presentations as soon as the video gets edited. Pamela was a keynote speaker at a large Girl Scout event and you can listen to the keynote speech on life, Scouting, astronomy, horses, and culture on the Slacker website

Pamela was delightful to work with and we had a great time with amateur astronomer from several local clubs and local educators talking about podcasting as an outreach tool and playing around with all the toys.

Venus

VE yesterday, returned the first ever images of the Venusian South pole providing not only and interesting day-side and night-side image but one in several different wave lengths. The mission to our 'twin' planet will hopefully answer:

• What is the mechanism and what is the driving force of the super-rotation of the atmosphere?
• What are the basic processes in the general circulation of the atmosphere?
• What is the composition and chemistry of the lower atmosphere and the clouds?
• What is the past and present water balance in the atmosphere?
• What is the role of the radiative balance and greenhouse effect in the past present and future evolution of the planet?
• Is there currently volcanic and/or tectonic activity on the planet

Mayans knew that it would appear in the morning sky after disappearing in the evening sky Moreover, they knew that every 2920 days (about eight years) Venus repeats its movements in relation to the sun. Mayans determined with great approximation the synodic period of Venus, which according to modern astronomers is 583.92 days. For the Mayans, it was 584 days!

So, how are we alike and different...

• Venus is 95% the size of Earth and 80% its mass
• Similar young craters
• Mostly large craters with crater trails indication the breakup of large objects. Small objects don't make it to the surface
• Tremendous atmospheric pressure 90 atm...similar to 1 km beneath Earth's the ocean
• Runaway greenhouse effect 400-750K (hot enough to melt lead)
• Hotter than all the planets including Mercury
• 350 phi winds in the upper atmosphere but only a few phi at the surface
• Gently rolling plains with a few shield volcanos
• Unique features include coronea which could be collapsed surface previously covering magma domes and pancake volcanos caused by the eruption of thick lava
• Planet only rotates once every 243 Earth days An a Venusian year is 225 Earth days
• Axial tilt of 177.36 degrees
• Orbital eccentricity of 1% almost perfect circle
• Orbits closer to the sun, inferior, thus has phases similar to our moon.
• Upper atmosphere wind circumnavigate the planet in 4 Earth days
• Venus has no magnetic field, perhaps because of its slow rotation.
• The oldest craters seem to be only 500 million years old, recent resurfacing - no steady pressure releases like on earth (venting earthquakes) instead massive global eruptions
• Most of the planetary features of Venus are named after famous women and goddesses pursuant to a decision of the International Astronomical Union, the organization responsible for selecting names for all celestial objects. craters - poets, artists, popular names; chasms - fairies, goddesses - undea (dunes) named after Sumerian and Arabian desert goddesses There is only ONE exception to this, James Clerk Maxwell the great Scottish physicist and theorist - father of electromagnitism has a mountain range named after him.

Listener Question

Christopher from Illinois was out looking at the planets and spotted something he had not seen before and emailed the following:

"...with tonight's full moon, I took your suggestion and went 
planet-hunting tonight Jupiter, Saturn, and Mars were
all present tonight though the moderate cloud cover and I 
saw something I've never seen before. There was a spectacular 
halo around the moon, occupying about 1/5th of the visible sky!  
Do you know what this could be?"

The 22 degree radius( from your thumb to your pinky) halos are visible any where on the planet and created by sun or moon. Always complete circles although sometimes the horizon can block some of the ring. They are caused by light refracting through ice crystals at high altitude.

On the other hand, corona are caused by water droplets they are very bright in the center and ringed with the subtle hues of rainbow colors and will grow larger or smaller as the cloud passing in front changes in density. Corona is produced by the diffraction of light. Small particles like water drops fine dust, ice can cause light to scatter light

The horizontal reflection point of the sun or the moon on the outside edge of a halo. Also called "false sun" or "false moon."

News

There are so many great space and astronomy news sites out there I won't try and duplicate them all, I'll just report things that really strike my fancy or that I think you might be interested in.

NASA's Mars Reconnaissance Orbiter

The Moon

The Sun

Sunspots are creeping back and I am hoping the clouds will stay away this weekend. We are having a solar viewing event and I would like to at least have a sun to share. Not to mention the fact that we are building stomp rockets!

Jay, at the Observing the Sky blog, posted tonight that at his clear moonlit site in N. Dakota he was out viewing aurorae!

Planets

• Venus - The brightest planet visible this month. Venus is outstanding in the Eastern morning sky and you will want to grab a pair of binoculars or even just a finder scope to check out her phase. Just over half full she is intensely bright in her gibbous phase.
• Jupiter - In Libra and Any telescope can reveal its two widest cloud bands to you, along with its four Galilean satellites. On Friday it will be just East of the Moon
• Saturn - Is in Cancer and tonight and moving East. It appears as a yellowish star that rivals Capella in brightness, A small telescope will always show Titan, Saturn's largest and most extraordinary moon.
• Mars has left Taurus and is just North of Castor's foot.
• Mercury - Just south of east about 25 degrees from Venus (towards the horizon and easterly) if you remember how to measure 25 degrees, it is the spread between your pinky and thumb when fully extended.
• Uranus - On April 17th, 18th and 19th, Venus and Uranus are going to have a close encounter in the dawn sky. Simply look east before sunrise. As a guidepost, Venus can't be beat. It is so bright people often think it's a landing airplane. Simply scan Venus with a pair of binoculars (or a small telescope) and you'll see Uranus right beside it. If the sky is very dark, you may be able to lift your eyes from the optics and see Uranus directly. On April 17th the pair will be separated by about one degree, the width of your pinky finger held at arm's length. On the 18th they'll be even closer together, 0.3 degrees. On the 19th the distance increases again to one degree.

Comets visible with binoculars/telescopes in the northern hemisphere.

"One touch of nature makes the whole world kin"
-- Shakespeare

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Music