05/14/2021 – Ephemeris – Astronomy Day Star Party this Saturday

This is Bob Moler with Ephemeris for Friday, May 14th. Today the Sun will be up for 14 hours and 48 minutes, setting at 9:03, and it will rise tomorrow at 6:14. The Moon, 3 days past new, will set at 12:07 tomorrow morning.

Tomorrow is International Astronomy Day, to celebrate it the Sleeping Bear Dunes National Lakeshore and Grand Traverse Astronomical Society will hold a special virtual star party via the Zoom Internet app. If it’s clear, Northwestern Michigan College’s professor Jerry Dobek will be transmitting live images of celestial objects that will look pretty much like what one sees through the eyepiece of a telescope. Dr. Dobek will be using the Joseph H. Rogers 0.4 meter main telescope and commenting will be members of the Grand Traverse Astronomical Society. Featured objects will be the 4-day-old crescent Moon, the tiny and elusive planet Mercury, star clusters and galaxies. The event starts at 9 pm though best viewing won’t begin until after about 9:30. Go to www.gtastro.org for instructions and a link.

The astronomical event times given are for the Traverse City/Interlochen area of Michigan. They may be different for your location.

Addendum

While attending the virtual star party you can capture the screen imaged with Alt/Print Screen keys. Paste the image into a paint or other program. I use GIMP (Gnu Image Manipulation Program), which fits my budget… It’s free. You can save the image of play with it. What I do with it is to darken the background. It should be black.

This is globular star cluster M 3. I call it the first globular cluster of spring. It’s near the star Arcturus. This is a screen capture cropped. The capture device on the 0.4 meter telescope is the Revolution Imager R2, which is actually fairly inexpensive. It outputs a video image.

I paste this image into GIMP. I use the Levels control under the Color tab.

I move the left control under the histogram to darken the sky. The left control here is set to 119, so all brightness values less than a brightness of 119 is set to black. Click OK and export the image. I didn’t change anything else.

Resultant image. Not bad. Though, I find globular clusters look better visually than their images. That is not true of nebulae or galaxies.