by Bob Vanderbei, Assistant Director

Here’s a picture I took of a pair of nebulas:  the Lagoon Nebula (aka M8) and the Trifid Nebula (aka M20).

I took this picture with my SeeStar S30 Pro telescope sitting on the sidewalk in front of my house here in Belle Mead NJ.  By default, the SeeStar telescopes are designed to be used in Alt-Az mode because it is simple for the user to set things up.  Just screw the small tripod into the bottom of the telescope, open the tripod legs, set the telescope somewhere on the ground or on a table, click the button to turn it on, open the SeeStar app on your cellphone or iPad, connect to the SeeStar, select the object you want to take pictures of and click on “Go There”.  After that everything is automatic.  Recently I bought the TH10 ZWO Tripod Head so that I can set up my SeeStar in equatorial mode (aka EQ Mode).  This takes an extra minute or two of setup time because one needs to make sure the azimuthal rotation axis is properly aligned with Earth’s rotation axis.  The SeeStar app helps with that and makes it quite easy.  This picture is the first long exposure picture I’ve taken with my SeeStar in EQ Mode.  It’s a stack of 564 20-second exposures.  That’s a total exposure time of 188 minutes.  The SeeStar app captured these images from about 10:30pm on July 8 to 2:00am on July 9.

The large nebula we see near the bottom is the Lagoon Nebula and the smaller nebula we see up by the top is the Trifid Nebula.  Both nebulas are emission nebulas that primarily are emitting red light from hydrogen atoms that are floating around in our Milky Way Galaxy.  That’s what makes what we call a nebula.  The Trifid Nebula is actually a little more complicated/interesting.  In addition to the red nebulosity it is also a star birthing area and so there are several young bright stars whose light reflects off from the nearby dust in the galaxy.   This reflected light is mostly blue and that’s the blue that we see in the nebula.  Astronomers are able to use those stars to accurately measure the distance to the Trifid nebula.  It is about 4100 light-years away from us here on Earth.  It is harder to get an accurate measure of the distance to the Lagoon Nebula.  It is estimated to be somewhere between 4000 and 6000 light-years away from us.