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Unread postPosted: Thu Feb 07, 2008 6:59 am 
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Lol Christo, what where you doing up at 3:30 am, working on the next question with the telescope out ?

Nice quiz :D


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Unread postPosted: Thu Feb 07, 2008 10:00 am 
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:lol: I was actually joking. You had me doing some real detective work. Though this is not difficult, it is actually "new" info, since most of this was only decided in 2006.

I learnt a few things ... and that is the idea!! (This is not a quiz for the know alls, but for those that want to learn! :wink: )

OK, let me think of a new question. :hmz:

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Unread postPosted: Thu Feb 07, 2008 10:03 am 
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bucky wrote:
Lol Christo, what where you doing up at 3:30 am, working on the next question with the telescope out ?

Nice quiz :D


Ill post the question at 3:31 after finishing a telescope session! :wink:

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Unread postPosted: Thu Feb 07, 2008 1:50 pm 
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I remembered something about these changes/re-classification of the planets, first to 12 and then to eight from the original nine. I could not help but have a chuckle about how confused astrologers should be, :lol: I had to use google the new info though.

Bucky I was already working on quotes, so unfortunately work and not play. :(

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Last edited by christo on Fri Feb 08, 2008 7:13 am, edited 1 time in total.

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Unread postPosted: Thu Feb 07, 2008 9:01 pm 
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As a 5th grader, I learned that our Solar System comprised nine planets viz. Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus, Neptune and Pluto.

This classification lasted until recently...and goodbye, Pluto...

On 24 August 2006, an assembly of the International Astronomical Union (IAU) in Prague, Czech Republic, (involving 424 astronomers), voted to remove Pluto's planetary status. Henceforth, it is classified as a "dwarf planet". Our Solar System now officially comprises eight major planets.

According to a new definition, a full-fledged/classical planet is an object that orbits the sun and is large enough to have become round due to the force of its own gravity. In addition, a planet has to dominate the neighborhood around its orbit.

Pluto has been demoted because it does not dominate its neighborhood. Charon, its large "moon," is only about half the size of Pluto, while all the true planets are far larger than their moons. In addition, bodies that dominate their neighborhoods, "sweep up" asteroids, comets, and other debris, clearing a path along their orbits. By contrast, Pluto's orbit is eccentric and crosses the path of Neptune and also takes it well above and below the main plane of the solar system.

First discovered in 1930 by Clyde Tombaugh (USA), Pluto was initially thought to be larger than it actually is (it is actually smaller than many moons in the Solar System)
Later research revealed objects that rivalled Pluto in size, but were not classified as planets.

The decision, which was not without controversy, establishes three main categories of objects in our solar system:
Planets:
The eight worlds starting with Mercury and moving out to Venus, Earth, Mars, Jupiter, Saturn, Uranus and Neptune.
Dwarf planets:
Pluto and any other round object that "has not cleared the neighborhood around its orbit, and is not a satellite."
Small solar system bodies:
All other objects orbiting the sun (such as comets and asteroids).

Here's a lineup showing the proposed 12 planet system, with a wedge of the sun at far left. Ceres, Pluto, Charon and 2003 UB313 are barely visible. Now Charon will continue to be considered Pluto's satellite, and the three other worlds will be dubbed "dwarf planets" rather than full-fledged planets. Ceres will be reintroduced as a planet, albeit as a "dwarf planet". The planets are drawn to scale, but without correct relative distances.

Image
Martin Kornmesser / IAU


Plutons: Pluto-like objects. The definition still remains unclear, and I think they are essentially "dwarf planets".
Pluto is the prototype for the new category of "Plutons", which include 2003 UB313.

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Last edited by cybeR@NGER on Thu Feb 07, 2008 9:56 pm, edited 1 time in total.

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Unread postPosted: Thu Feb 07, 2008 9:18 pm 
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Come on now guys, one of the first rules was 'keep it simple' :?
We want to learn but baby steps please.


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Unread postPosted: Fri Feb 08, 2008 1:04 am 
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Name the three most prominent red giants in our night sky.

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Unread postPosted: Fri Feb 08, 2008 7:18 am 
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cybeR@NGER wrote:
Ceres will be reintroduced as a planet, albeit as a "dwarf planet"


Does this mean Ceres does not have to have a round shape, as it is/was an asteroid? :hmz:

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Unread postPosted: Fri Feb 08, 2008 8:53 am 
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Not sure on these
A. A moon
B. A planet
C. A sun

Karl :?


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Unread postPosted: Fri Feb 08, 2008 9:24 am 
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Ceres is round.

Clue: A "red giant" is a specific type of star ...

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Unread postPosted: Fri Feb 08, 2008 9:29 am 
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beetle juice or Antares
Sorry for the spelling


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Unread postPosted: Fri Feb 08, 2008 2:06 pm 
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Yes, that is two :clap:

Antares in Scorpius which is prominent in the winter.
Betelgeuse in Orion which is prominent in summer.

And ...

BTW Here is an image of ceres.


Image

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Unread postPosted: Fri Feb 08, 2008 3:20 pm 
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christo wrote:
cybeR@NGER wrote:
Ceres will be reintroduced as a planet, albeit as a "dwarf planet"


Does this mean Ceres does not have to have a round shape, as it is/was an asteroid? :hmz:

Christo, Ceres does have a round shape as you can see in Hubble's image posted by Imberbe.

The classification of Ceres has changed a few times, since its discovery in 1801. First, it was thought to be the "missing" planet that astronomers believed existed between Mars and Jupiter. It was, therefore, assigned a planetary symbol for about 50 years. Afterwards, other similar objects were found in the area and it was realised that they represented a group of bodies with the same characteristics and the name "Asteroid" as coined.
Ceres remained an asteroid until 24 August 2006 following the IAU assembly in Prague which decided to "promote" it to a "Dwarf Planet" along with Pluto. This was a direct consequence of the new definition of a planet, as explained earlier.

Imberbe wrote:
Antares in Scorpius which is prominent in the winter.
Betelgeuse in Orion which is prominent in summer.

And ...

Aldebaran, in the the constellation Taurus ?

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Unread postPosted: Fri Feb 08, 2008 3:48 pm 
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Nice info on Ceres...

No, Rigel is not a red giant.

Clue: Seen from the casual stargazers perspective, the third red giant is part of a very well known constellation, that is quite close to Orion.


RED GIANT EXPLAINED IN VERY BASIC TERMS:

The term "red giant" is very descriptive of this type of star. It is a huge star that burns in the red spectrum. The colour red indicates that it is relatively cool, as opposed to stars that burn warmer (yellow - the sun) and even warmer (blue - Rigel).

These stars are huge! If the centre of Betelgeuse were where the centre of our sun is, the earths orbit would have been inside the star! The reason why they are so big, is because they are very old, and has burnt up most of their hydrogen. The nuclear reaction shifts from the core to the outer layers, causing the star to swell. Its diameter may grow hundreds of times larger.


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Unread postPosted: Fri Feb 08, 2008 3:51 pm 
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:lol: You changed your answer while I was posting!!

Naughty, but correct! Aldebaran indeed!

OK ... CybeR@nger, your question!
:wink:

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