Denver StarParty Newsletter 1,April 15th there or abouts Denver StarParty Newsletter 1,April 15th there or abouts
At A Glance
Brief update
Hot happenings
(Also a bit about Regulus – the heart of Leo)
FYI
Plans
Christina bikini clad hot tubbin’ astronomer??!!!
Brief Update
Things are picking up pretty fast and I am very pleased with the over 30 or so Great members we have after just a few short weeks. Their enthusiasm and participation has been heat warming but even better we have had great skies !! Smores, steaks, hot tub, roasting marshmallows and great, great people.
Five planets visible
In a spectacular night show that won't be back for another three decades.
Mercury, Venus, Mars, Jupiter and Saturn -the five closest planets - should be easily visible at dusk,
along with the moon Standish said this particular planetary grouping may offer the best nighttime views until 2036.
April 1st even though smitten with some overcast (my karma!) best view of jupiter to date!
Leo the Lion (Spring-constellation) begins taking Orion (Winter-constellation) spot
Leo the Lion (Spring constellation) begins takes Orion (Winter constellation) spot of
the sky marking the beginning of spring, and the leaving of winter. So high flying (Leo) and low lying(Orion). Leo is reclining. The star Regulus is his heart (Regulus means "Loyal...King") Leo is only 1/2 degree from the ecliptic (we will go into the details later, but roughly it is the line going from sun to moon, moon will be close to it. Leo is about 85 light years away, which means if you are 85 years old you are seeing it as it was when you were born!
A bit about Regulus:
Regulus
5x the diameter of our sun, 150x suns brightness25x further away than the moon
Source:
Jack Horkheimer, director of the Miami Planetarium and host of the PBS series "Star Gazer,"
The Ecliptic explored
I have noticed a few people have talked about the "Ecliptic" so since a few of us don’t know what that is, I myself am a little fuzzy I decided to put it into our first newsletter.
The Path of the Sun, the Ecliptic
The apparent path of the Sun across the sky.
In summer, the Sun's path is longest, and so are the days.
In winter, the Sun's path is shortest, and so are the days.
The path of the Sun across the celestial sphere is very close to that of the planets and the moon. After clocks became available, it was a relatively straightforward job for astronomers to relate the path of the Sun in the daytime to the one of stars at night, and to draw it on their star charts. Because of its relation to eclipses, that path is known as the ecliptic.
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The orbit of the Earth around the Sun. |
The significance of the ecliptic is evident if we examine the Earth's orbit around the Sun. That orbit lies in a plane, flat like a tabletop, called the plane of the ecliptic (or sometimes just "the ecliptic"). In one year, as the Earth completes a full circuit around the Sun (drawing above), the Earth-Sun line and its continuation past Earth sweep the entire plane. The far end of that line then traces the ecliptic on the celestial sphere; if you have a star chart handy (it is often included in an atlas), you will find the ecliptic traced there, too.
Planets seen in the sky are always near the ecliptic, which means that their orbits are never too far from the plane of the ecliptic. In other words, the solar system is rather flat, with all its major parts moving in nearly the same plane.
What about the connection between "ecliptic" and eclipses?
The moon's orbit cuts the ecliptic at a shallow angle, around 5 degrees, which means that on the celestial sphere the Moon, too, follows a path through the zodiac. Half the time the Moon is north of the ecliptic, half the time south of it. If the shadow of the moon hits the Earth, the Sun is eclipsed in the shadow area; if on the other hand the shadow of the Earth covers the moon, the moon goes dark and we have an eclipse of the moon.
Either of these can only happen when the Sun, Earth and Moon are on the same straight line. Since the Sun and Earth are in the plane of the ecliptic, the line is automatically in that plane too; if the moon is also on the same line, it must be in the plane of the ecliptic as well.
It takes close to a month for the Moon to go around the Earth ("month" comes from "Moon") and during that time its orbit crosses the ecliptic twice, as it goes from one side to the other. At the time of crossing, the Sun may be anywhere along the ecliptic; usually it is not on the Earth-Moon line, and therefore an eclipse usually does not take place. Occasionally, however, it is on that line or close to it. If it then happens to occupy exactly the same spot on the celestial sphere, we get an eclipse of the Sun, because the moon is then between us and the Sun. On the other hand, if it occupies the spot exactly opposite from that of the Moon, the Earth's shadow falls on the Moon and we have an eclipse of the Moon.
Source: http://www-istp.gsfc.nasa.gov/stargaze/Secliptc.htm
September 21, 1996
The Ecliptic Plane
Credit:
Explanation: The Plane of the Ecliptic is illustrated in this Clementine star tracker camera image which reveals (from right to left)
the Moon lit by Earthshine, the Sun's corona rising over the Moon's dark limb, and the planets Saturn, Mars, and Mercury. The ecliptic plane is defined as the imaginary plane containing the Earth's orbit around the Sun. In the course of a year, the Sun's apparent path through the sky lies in this plane. The planetary bodies of our solar system all tend to lie near this plane, since they were formed from the Sun's spinning, flattened, proto-planetary disk. The snapshot above nicely captures a momentary line-up looking out along this fundamental plane of our solar system. Also see: Astronomy Picture of the DayIf the sun's path is observed from the Earth's reference frame, it appears to move around the Earth in a path which is tilted with respect to the spin axis at 23.5°. This path is called the
ecliptic. It tells us that the Earth's spin axis is tilted with respect to the plane of the Earth's solar orbit by 23.5°. Observations show that the other planets, with the exception of Pluto, also orbit the sun in essentially the same plane. The ecliptic plane then contains most of the objects which are orbiting the sun. This suggests that the formation process of the solar system resulted in a disk of material out of which formed the sun and the planets. The 23.5° tilt of the Earth's spin axis gives the seasonal variations in the amount of sunlight received at the surface.Pluto 's orbit is exceptional in that its orbit makes an angle of 17° with the Earth's orbit . This has led to a number of theories about Pluto's origin.
Mercury is the only other planet which moves significantly away from the ecliptic plane ( 7°) .The apparent path of the Sun's motion on the
celestial sphere as seen from Earth is called the ecliptic. The ecliptic plane is tilted 23.5° with respect to the plane of the celestial equator since the Earth's spin axis is tilted 23.5° with respect to its orbit around the sun. The ecliptic plane intersects the celestial equatorial plane along the line between the equinoxes.Next week: Celestial Sphere, Declination and Right Ascension
The Jack Horkheimer Award
FYI
The Jack Horkheimer Award is presented to any Astronomical League member under the age of 19 on the date of the application. This year, in addition to the $1,000 award, Celestron International is providing one of its higher quality telescopes to the 1st place winner. We appreciation Celestron's generous contribution to promoting amateur astronomy among our country's youth. 
Teresa child genius Edmonds First Place
You can bet I will actively seeking participation with my just turned 7 year old daughter, TWO times 1st place physics award (2cd on April 3rd), both times ONLY the first grader to win, in this event this summer!!! (yes, er, uhm very proud dad, hehe)
For more info see:
http://www.astroleague.org/al/awards/horkhmr/horkhmrs.html
Plans
Find Leo
We need to locate this new beastie. So be looking for him now so u can help us find him Thursday night!
We need to come up with a group name, a group logo, any ideas, do we need a contest
Right now we are in the formative stages of the idea of a dark sky area to view the skies. We have tentatively scheduled Chistina’s house for the first one and Saturday being the day. The first one will be Next Saturday, April 17th directions will be posted on web site.
http://www.omnisoft.net/StarParty/