Astronomical Society

of Long Island


NOTICE:  All content on this site is Copyright ©2016 by Ken Spencer, The Astronomical Society of Long Island, and the respective photographers.  All Rights Reserved.  Reproduction is forbidden without express written permission.


May 3 - The Cryptic Case of the Campbell Clark - by Bart Fried. In old Brooklyn, a very large refractor goes almost completely unnoticed in the scientific community and is left off of every list of large telescopes and observatories that was published at that time. Yet it was one of the largest refractors in the world. This talk will discuss the hunt to uncover it’s mysterious past and how the ‘rabbit hole’ was finally filled in.

May 10 - Gadgets & Gismos: The Latest and Greatest in Astronomical Tools and Toys  - by Jeff Norwood  A plethora of new and exciting items that will make your astronomy observing experience more interesting and rewarding, and of course make your wallet lighter.  But that’s why we are in this hobby in the first place, right?

May 17 - Diffraction of Light and Astronomy - by Steven Bellavia. This talk focuses (pun intended) on how the diffraction of light, a phenomenon that results from the wave nature of light, discovered in the 1600’s affects amateur and professional astronomers in viewing and imaging the universe. It includes a brief historical discussion, and then shows what causes the resolution limit in telescopes, demonstrates diffraction spikes, and how this often weird, but predictable behavior can be used for the good of astronomy and cosmology. Steve is an amateur astronomer and telescope maker, and is an accomplished astrophotographer. He is an aerospace engineer at Brookhaven National Laboratory and is the principal mechanical engineer on the camera for the Large Synoptic Survey Telescope.

May 24 - Observing Night - Weather Permitting, with new moon. We will only observe if the skies are clear. Bring your own telescope or binoculars, or come and observe through our instruments. Please do not park on the lawn.

May 31 - Installing a new 10-inch refractor - by John Speroni.   Custer Institute & Observatory recently installed a new telescope, mount, and pier. Why was that equipment selected? How were installation challenges solved? And what is a “retrofocally corrected apochromatic dialyte?”  Come hear this talk, and then you will know!

Messier 27 - The Dumbbell Nebula

This is a magnificent image of The Dumbell Nebula done recently by ASLI member Jonathan Nelson.  This object was the first planetary nebula to be discovered; by Charles Messier in 1764. At its brightness of visual magnitude 7.5 and its diameter of about 8 arc minutes, it is easily visible in binoculars, and a popular observing target in amateur telescopes.  However, in amateur instruments it only appears as a black and white image because of the inability of the human eye to see color in very low brightness.  Doing long exposure astrophotography like this is a very demanding process.  The total time of all exposures exceeds one hour and thirty minutes!  Here are the technical details:

Scope: Explore Scientific 102ED Triplet Essentials Series

Mount: Celestron AVX

Guiding: Orion Magnificent Mini AutoGuider Package

Camera: Canon Rebel T5

Other: Explore Scientific Field Flattener and Orion SkyGlow Imaging Filter

Capturing Software: BackyardEOS (with dithering), PHD2

Processing: Entirely in Pixinsight 1.8

Light Frames: 19 x 180" (57 min total)

Dark Frames: 10 x 180"

NGC 4216 in the Virgo Cluster by Dave Barnett

Our intrepid astrophotographer Dave Barnett apparently needs no sleep at all, judging by his latest handiwork.  In the center of the frame is the galaxy NGC 4216 in the Virgo Cluster.  It is 40 million light-years distant, and is an edge-on spiral galaxy.  It is nearly 100,000 light-years across, about the size of our own Milky Way galaxy.  It is flanked by fellow Virgo cluster member NGC 4222.  If you are thinking of trying astrophotography, you should know this is not a simple trick.  He used an 8” f/4 Newtonian, and this final image is a stack of 4 minute long sub exposures with a total time of 92 minutes.