April 2024
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Chasing Galileo - fourteen-day moon

fourteen-day (full) moon

The full moon rises as the sun sets on the 14th day of the lunar month. A small telescope, such as the 70mm f.8.7 Televue Ranger I’m using for this series of sketches is a perfect instrument for full moon viewing. So are binoculars. The moon is [...]

Chasing Galileo: the Trapezium

Galileo’s Trapezium

My Trapezium sketches

Galileo’s observed the Trapezium stars in the sword of Orion on February 4, 1617. He labeled the three stars “c”, “g”, and “i”. These stars are known now as the “D”, “C” and “A” components of Theta 1 Orionis, or 41 Orionis. He did not see the fainter [...]

Chasing Galileo: the Pleiades

Galileo’s Pleaids

My sketch of the Pleiades

Galileo’s sketch of the Pleiades was published in Sidereus Nuncius in 1610.

Galileo identified four levels of stellar magnitude. He represented the six naked eye stars he could see with a large star symbol. These 6 stars were listed in Ptolemy’s Star Catalog. Next come seven stars [...]

Chasing Galileo - sketches of the moon

Folio page 28 manuscript copy of Sidereus Nuncius

sketch of 3-day old waxing moon 2-28-09

sketch of 5-day old waxing moon

sketch of 14-day (full) moon 3/11/09

Galileo’s watercolor drawings were made with brown ink wash on watercolor paper. To me, these are the most beautiful of Galileo’s astronomical renderings. When I look at the [...]

Chasing Galileo: sketches through a small refractor

Galileo telescope replica and my TV Ranger

Galileo's 1609 telescope

There were separate housings at either end for the objective and the eyepiece

When I started thinking about how to integrate International Year of Astronomy into my 2009 What’s Up podcasts I naturally focused on Galileo’s first observations through a telescope 400 years [...]