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Backyard Astronomy

Saturn as Seen from Titan - Chesley Bonestell, 1944.
Copyright (c) Bonestell Space Art, used with permission.

Jack Harper enjoys backyard amateur astronomy with his Celestron NexStar 11 GPS, his little Celestron C5+, and his Cave Astrola ten-inch reflector (currently being refurbished).

His primary interests are planetary and lunar observations as well as some deep space work as equipment permits. Harper is also working toward trying to become proficient with astrometry -- orbit determination for asteroids and comets.

He is a member of the Denver Astronomical Society which meets monthly at the Chamberlain Observatory in Denver.

Transit of Mercury - On 15 Nov. 1999, Mercury transited across the sun at ~21.30 UT. J. Harper took this photograph through the Celestron C5+ with a glass solar filter, Pentax SP-IIa body @ 1/250th Second, Tri-X B&W ASA 400 film, Prime Focus. Mercury is the small dot seen against the solar limb.

Interesting Links

Sounds of Pulsars
.wav recordings taken from the Parkes Observatory web site in Australia in case the recordings disappear -- See the site for an explanation of Pulsars.
PSR B0329+54 is a typical pulsar that is rotating about 1.4 times per second.
PSR B0833-45 is a pulsar located in the constellation Vela which is seen in the southern hemisphere. The pulsar is the collapsed core of a supernova and is rotating about 11 times per second.
PSR B0531+21 is the pulsar located at the center of the Crab Nebula in the constellation Tau. It rotates about 30 times per second.
PSR J0437-4715 is a millisecond pulsar that has been spun up by the accretion of material from a companion star. The pulsar is spinning at about 174 times per second.
PSR B1937+21 is the fastest known pulsar that is spinning at about 642 times per second. The surface of the star is moving at about 1/7th the velocity of light.

Sounds of Jupiter
.wav recordings taken from the Radio Jove NASA site in case they disappear -- See the site for a very good explanation. These signals can easily be received by amateur equipment.
S Burst received from Jupiter -- these signals are similar to VLF Whistlers found on the earth but have a very fast drift rate of from 10-MHz to 30-MHz per second. They sound like a pop as their frequency zips past the receiving frequency of the radio.
L Burst received from Jupiter -- these signals have rich frequency components with instantaneous bandwidth of up to 5-MHz. The signals sound very much like ocean waves on a beach.

Passing of Near Earth Object (NEO) Asteroid 1998 WT24 on 011216

On 16 December 2001, the one-kilometer diameter (0.6-miles) asteroid 1998 WT24 passed within less than 1.5-million miles of the Earth. This sounds like a long ways, but it is only about five times further from the Earth than the distance to the Moon -- and only about 1/100th the distance to the Sun.

NEO 1998 WT24 passed closer to the Earth than any other known asteroid since 1969. An NEO impact on the Earth could easily result in an Extinction Event.

It is interesting to note that 1998 WT24 was first detected only a few years ago. An even larger object (not an NEO -- comet Shoemaker-Levy) was observed to impact the planet Jupiter in 1994...

Following are several remarkable images that were taken of 1998 WT24 as it passed by the Earth. The images are from and and are repeated here in case they disappear.
Animated .gif taken by S. Gadjos and J. Toth of the Comenius University in Slovakia captured this sequence of images using a 60cm reflector f/5.5 + ST8 CCD from 19:44 to 20:00 UT on Dec. 14th.
T. Puckett of Ellijay, Georgia, USA: "This animation of 1998 WT24 was obtained with a 60 cm reflector working at f/5.7. The movie was made from 75 one-minute exposures taken with an Apogee AP7 CCD camera." Copyright 2001ŠTim Puckett.
This movie by John Rogers of Los Angeles, California shows 3.9 hours of motion by 1998 WT24 when the asteroid was 0.028 AU from Earth.
NASA's Steve Ostro used the Deep Space Network antenna at Goldstone, California to make close-up radar images of the asteroid, which are seen in an animation - Remember that what you are looking at is a mountain over half a mile in diameter tumbling through space at something like 100,000 miles/hour (~160,000km/hr)...

The Strange Life and Death of Robert Burnham

Robert Burnham (shown at right) wrote the very famous and very useful Burnham's Celestial Handbook (Volumes I - III) which are truly the Standard Bible for North American amateur astronomers. I use mine frequently when planning an evening's observations or when just reading for fun in front of the fireplace on a rainy day. Burnham started writing his Handbook in 1955 and had it first published by Dover in 1978. It has over 2,100 marvelous pages, 750 plates, and hundreds of diagrams that carefully dissect the 88 constellations one by one. Over 7,000 celestial objects are listed and detailed. But, the books are not just dry tables and charts -- they describe the Lights in the Sky with not infrequent poetic prose and are beautiful works to read.

Robert Burnham, who graduated only from high school, discovered six comets, was one of the greatest observational astronomers of the 20th century, and yet died alone as an almost penniless old man with a gangrenous foot while selling paintings of cats in Balboa Park in San Diego. His is an interesting and strange story.

SkywriterExcellent article from the Phoenix New Times about the strange life and death of Robert Burnham
Amazon.comSee what the customer reviews at have to say

Global City Lights

The best satellite image of the darkside of Earth that I have seen....

Click Photo to Download High-Resolution Photo (386 Kb) -- Actually a Composite of hundreds of photos taken by the Defense Meteorological Satellites (DMSP).

It is interesting to note the various economic and political patterns that are visible. For example, look at the remarkable regular grid of very small towns that are in the midwest of the United States that are a result of the government land grants to the railroads in the late 19th century whereby county seats were created every so many miles. I was born in one of those tiny dots that still exists -- Paducah, Texas :)

Perhaps the most striking political pattern shows vividly in the difference between South Korea and the Socialist North. The contrast is amazing - the South is a blaze of light while the North is almost completely dark..

The linear patterns formed along the Trans-Siberian Railroad are also remarkable. Look at the intense development along the Nile River in Egypt. The central backbone mountains of Italy are almost dark. The road between Delhi, India south to Agra where the Taj Mahal is located is striking even though the highway itself is a small two-lane road. Islands show up nicely -- Stewart's Island in the southern most part of New Zealand; the Cape Verde Island just west of the equatorial bulge of Africa; and, of course, Stanley in the Falklands...

Photo from the NASA site at in case it disappears...

Live Telescopes
Current Hydrogen-Alpha Solar ImageLive Solar Image

Astrometry and Software
Guide to Minor Body AstrometryExcellent Beginner's Guide - FAQ et. al.
Astrometry of AsteroidsSoftware...
How to Do AstrometryBasic Info...
Astrometry - Photometry TutorialTutorial...

General Astronomical Software
Dan's Astronomy SoftwareVery nice site, by Dan Bruton, of different software packages that display the relative position of Saturn's moons for a given date and time; display the position of the Jovian satellites; display the position of the Great Red Spot on Jupiter; and many others. He also has links to hundreds of astronomical software packages. -- Last Revision: 24 April 2010
Copyright © 1998 - 2017 Jack Harper (unless otherwise noted)
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