ASTRONOMY CLUB OF TULSA
ACT, Inc. has been meeting continuously since 1937 and was incorporated in 1986. It consists of approximately 150 members and is a nonprofit; tax deductible organization dedicated to promoting, to the public, the art of viewing and the scientific aspect of astronomy.
The Astronomy Club
of Tulsa Meeting
Friday May 28, 1999
at 7:30 P.M.
Room M1 inside
Keplinger Hall, the Science & Engineering Building at TU.
Enter the parking lot on the East Side of Keplinger Hall from
Harvard and 5th Street. This will take you directly toward the
staircase to enter the building. Room M1 is the first room on the
June 25, July 30,
and August 27
THIS MONTH'S PROGRAM:
A WORD FROM
DAVID'S ASTRO CORNER
By David Stine
When was the last time you could go
in your backyard and view a comet? It has been quite a long spell
since that was possible, but for a few weeks that wait is over.
Steven Lee, an amateur astronomer, discovered Comet Lee while at
a star party near Mudgee, New South Wales in April. Circumstances
were very similar to the way Comet Hale-Bopp was discovered. This
comet will in no way get as bright as Hale-Bopp, but it is
beginning to shape up as a decent backyard telescope comet. Comet
Lee is to reach perihelion on July 11, 1999. At that time, the
long period comet will be at a distance of 0.71 AU, which is
about the distance of Venus from Earth. The downside is that it
will be on the other side of the sun and not visible at that
time. Now is your best shot at viewing Lee. The comet is
traveling very fast northward at this writing and is already
reported to be brighter than Mg. 7., which already has exceeded
earlier predictions. Rusty Fletcher, our fearless leader,
observed the comet at the recent Texas Star Party and reported it
as quite bright with a small faint tail. On the night of May 19,
K.C. Lobrecht reported that from the RMCC Observatory, that Comet
Lee was just gorgeous. It was like M13 and better than Mars.
According to K.C. it will blow you away in weeks to come. She did
say she felt it was moving even more rapidly than predicted and
that the coordinates are off by a degree or so. She estimated it
to be as bright as Mg. 6.9. For the next two weeks, Lee is
expected to brighten even more, possibly reaching naked eye
visibility by the end of June. By mid June it will move into
Cancer, but start getting lower on the horizon. In early July it
will be its brightest, somewhere between 6th and 7th Mg., but it
will be quite low in the evening sky. By the 10th, Lee will be
lost in the sun's glare. After perihelion, Comet 1999 H1 Lee,
will return to view in the early morning hours in August. By
August 11th, Lee will be visible prior to morning twilight and
will have faded to about Mg. 7.6. August 15th, it will be moving
through western Auriga. By September, although faded to Mg. 8.5,
it will become a circumpolar object, viewable all night long. In
October it will be high in the sky by 11p.m. in Andromeda at Mg.
9.3. Then by the end of the month it will have passed into
Pegasus, and fade rapidly to 12th Mg. by mid November. But for
now, on May 28th, ACT Club meeting night, the comet will be below
the stars that make up the head of Hydra in the West. I will
bring my telescope to the meeting and we can view it afterwards.
Below are coordinates for the comet from May 28th through June 8.
These are the latest, but could change a degree or so depending
on how fast the comet moves. MG. estimates are already incorrect
so I did not list them. Comets can be very unpredictable when it
comes to brightness predictions as this one has already exceeded
brightness predictions. Again I warn, don't expect to see a Comet
Hale-Bopp, that was an unusual comet, but Lee will not
disappoint. Additional information and the latest updates on
Comet Lee can be obtained at the following website:
http://antwrp.gsfc.nasa.gov/apod/ap990427.html. I will also have
a few copies of Comet Lee's path through the sky at the meeting
for those interested in tracking this visitor from deep space.
May 28: 8hrs38.8min RA, -0deg35min dec
C/1999 H1 (Comet Lee)Orbital Elements: T 1999 July 11.1652 TT, Q=0.708294, E=1.0,
Peri.=40.6733, Node=162.6417, Incl.=149.3545
The following coordinates are the latest for Comet C/1999 H1 (Lee)
May 29: 8hrs37.6min RA, 0deg36min DEC
May 30: 8hrs36.4min RA, 1deg45min DEC
May 31: 8hrs35.2min RA, 2deg51min DEC
June 1: 8hrs34.1min RA, 3deg54min DEC
June 2: 8hrs33.1min RA, 4deg55min DEC
June 3: 8hrs32.0min RA, 5deg54min DEC
June 4: 8hrs31.1min RA, 6deg51min DEC
June 5: 8hrs30.1min RA, 7deg46min DEC
June 6: 8hrs29.2min RA, 8deg38min DEC
June 7: 8hrs28.3min RA, 9deg29min DEC
June 8: 8hrs27.4min RA, 10deg19min DEC
That's its from my Astro Corner this month.
May 28: 8hrs38.8min RA, -0deg35min dec
CSAS Star Party
Are you planning a family vacation
for this summer and want to incorporate some spectacular
observing? Come to Colorado in July!!
You are invited to join the Colorado Springs Astronomical Society at the 13th annual ROCKY MOUNTAIN STAR STARE, July 8-11. This is one of the biggest amateur gatherings in the Rocky Mountains, with over 300 observers expected this year. This year's site is at an elevation of nearly 9000 feet, about an hour's drive west of Colorado Springs. Also featured this year is the Astronomical League's MARS South regional meeting. (MARS stands for "Mountain Area Research Section")
We are located in the heart of Colorado, with lots of nearby attractions,
including fishing, hiking, site-seeing, white-water rafting, and everything else that makes Colorado a wonderful vacation destination. If you visit the Colorado Springs area over the 4th of July holiday, you can even check out the highest road race in the country - the Pikes Peak Hill Climb - that takes brave drivers to over 14,000 feet of elevation.
If you would like to learn more, please visit the RMSS page from our web site: http://members.aol.com/bygrens/CSAS.html
There you will find everything you need, including driving directions, camping suggestions, tentative speaker and events schedules, and our pre-registration instructions. We look forward to seeing you this summer in Colorado!
Steve - CSAS webmaster email@example.com
May SKY FORUM
By Don Cole
Neptune is the fourth largest of the planets
in the solar system, and eighth major planet in order of increasing distance
from the sun. The mean distance of Neptune from the sun is 4.5 billion
km (2.796 billion mi), and its mean linear diameter is approximately
49,400 km (approximately 30,700 mi), or about 3.8 times that of the earth.
Its volume is about 72 times, its mass 17 times, and its mean density 0.31
that of the earth (about 1.7 times that of water). The albino of the planet
is high; 84 percent of the light falling on it is reflected. The period of
rotation is about 16 hr, and the period of revolution about the sun is 164.79
earth years. The average stellar magnitude (see Magnitude below) of the
planet is 7.8, and it is therefore never visible to the naked eye, but it can
be observed in a small telescope as a small, round, greenish-blue disk without
definite surface markings. The temperature of the surface of Neptune is
about -218 degrees C (-360 degrees F), much like Uranus, which is more than
1 billion miles closer to the sun. Scientists assume, therefore, that
Neptune must have some internal heat source. The atmosphere consists mostly
of hydrogen and helium, but the presence of up to three percent methane gives
the planet its striking blue color.
*** Astronomy Dictionary *** *** From The Cargo Bay *** ------------------------------- Astronomy
Club meeting dates for 1999. The club
will meet the last Friday of each month except for November and
December when a holiday will interfere with the last Friday. The
November meeting will be on the 19th, and the December meeting
will be on the 17th. The dates are: 28 May 25 June 30 July 27 August 24 September 29 October 19 November 17 December Thats all
Approximately eight known satellites orbit Neptune, two of which are observable from earth. The largest and brightest is Triton, discovered in 1846, the same year Neptune was first observed. Triton, with a diameter of 2705 km (1680 mi), is only slightly smaller than earth's moon. It has a retrograde orbit-that is, it moves in the opposite direction to the planets direction of rotation - unlike any other major satellite in the solar system. Despite its extreme coldness, Triton has a nitrogen atmosphere with some methane and some form of haze, and it displays an active surface of geysers that spout an unknown subsurface material. Nereid, the second satellite (discovered in 1949), has a diameter of only about 320 km (about 200 mi). Six more satellites were discovered by the Voyager II planetary probe in 1989. Neptune is also circled by five thin rings. Its magnetic field is tilted more than 50 degrees to the rotation axis.
The discovery of Neptune was one of the great triumphs of mathematical astronomy. In order to account for perturbations in the orbit of the planet Uranus, the French astronomer Urbain Jean Joseph Leverrier in 1846 calculated the existence and position of a new planet. That same year the German astronomer Johann Gottfried Galle (1812-1910) discovered the planet within 1 degree of that position.
(Magnitude), term used to designate the apparent brightness of a star as viewed from the earth. The ancient Alexandrian astronomer Ptolemy originally divided all visible stars into six magnitudes: the brightest were called first magnitude, those barely visible to the naked eye were called sixth magnitude, and the other visible stars were assigned intermediate positions. In the 19th century a standard system was finally adopted under which a star of any given magnitude is 2.512 times as bright as a star of the next higher magnitude; thus, for example, a star of the second magnitude is 2.512 times as bright as a star of the third magnitude. The advantage of this particular magnitude ratio, 2.512, is that it coincides closely with the Ptolemaic system; and because 2.512 is the fifth root of 100, a star of the first magnitude is exactly 100 times as bright as a star of the sixth magnitude, a star of the sixth magnitude is exactly 100 times as bright as a star of the 11th magnitude, and so on. Stars brighter than magnitude 1.5, of which there are 20, are called first-magnitude stars. Thus, the first- magnitude star Aldebaran has an actual magnitude of 1.1; the slightly brighter first-magnitude star Altair has a magnitude of 0.9. The brightest stars are brighter than magnitude zero. Sirius, the brightest star outside the solar system, has a magnitude of -1.6. The sun has a magnitude of -26.7, inasmuch as it is about 10 billion times as bright as Sirius in the earth's sky.
(Absolute magnitude), as opposed to apparent magnitude, indicates the brightness that a star would have if it were placed at a distance from the earth of ten parsecs, or 32.6 light-years. By rating stars in this way, astronomers are able to compare them with respect to intrinsic brightness. The sun, for example, has an absolute magnitude of +4.7.
Why are the Orbiter cargo bay doors opened once they are on station (in orbit)? This is a vital first task, because the radiators that shed, get rid of, or radiate the excess heat generated by the Orbiter are located and actually built into the inner surface of the cargo bay doors. If the doors remain closed, heat builds up within the vehicle and the mission will have to be aborted within 8 hours. Once the thirty two latches are released the doors can be opened and all systems are up and running, the mission can last anywhere from 7 to 30 days are possible. Once the Orbiter is in orbit how does it maneuver in space?
So until next month Dark Skies and Steady Seeing to You ...
Reference Material :: "Astronomy, A self-teaching guide." by Dinah L. Moche (4th ed.) "Guide to the Stars" by Leslie Peltier. " Astronomy, For the Earth to the Universe" by Jay M. Pasachoff (3rd ed.)
*** Astronomy Dictionary ***
*** From The Cargo Bay ***
Astronomy Club meeting dates for 1999.
The club will meet the last Friday of each month except for November and December when a holiday will interfere with the last Friday. The November meeting will be on the 19th, and the December meeting will be on the 17th.
The dates are:
Thats all folks