Constellation Report

Our Constellation Report is an easy way for people to become familiar with the nighttime sky. We’ll discuss myths associated with a particular constellation as well as describing the numerous deep sky objects residing within its boundaries. No equipment is required to view the constellations, though a star chart can be quite helpful. This ease of observing makes constellations a natural place to begin your journey to the stars. 

This weekend we move on to the constellation Sagitta the Arrow. 

Deep Sky Report

The focus of our efforts this week will be the deep sky objects of Sagitta. Sagitta is located just southeast of the constellations Cygnus and Vulpecula. Sagitta very definitely looks like an arrow pointing towards the northeast. 

To begin with, I'd like to tell you that this region is going to challenge your observing skills. Except for our first object, the deep sky objects in this constellation are either very faint, very small, or both. You're definitely going to need dark skies, a decent sized telescope, and a bit of patients to find these. 

Ok, let's get things started. One very interesting star to check out is U Sagittae. It is what astronomers refer to as an eclipsing variable star. This is a star system in which the bright primary star is completely eclipsed by it's larger but fainter companion. The pair, which consists of mag6 and mag9 components, eclipse each other every 3 days or so. They remain at this dramatically dimmed level for about 40 minutes and then they begin to brighten again. The pair is easily observed in binoculars or a small telescope.

Let's begin by observing this week's lone Messier object, Globular Cluster M71(mag8.3). At a distance of only 13,000 light years, this globulars visual appearance more closely resembles a dense open cluster. You'll find M71 located midway between Gamma and Delta Sagittae, this cluster spans about 7'. 

This gorgeous shot was taken by © T. Credner & S. Kohle, AlltheSky.com.

We'll wrap up our journey through Sagitta with a visit to this weeks Utah Skies Challenge Object, Planetary Nebula IC4997(mag12). This small nebula also has a diameter of about 6'.
Checkout the accompanying Hubble image. Ignore if you can the prominent X shape which is visible through the center of the image, this is an artifact of the telescope used to capture this image. Astronomers have discovered extremely young jet-like components in this nebula. These are extremely powerful blasts from an unknown source. Could a pulsar or some other exotic object be at the center of this nebula???

This is a tough object to find. A good technique to use is to blink an OIII filter. By that, you'd move the filter in front of the eye piece and then remove it. If you're on the nebula, it will brighten relative to the surrounding stars.

Good Luck!