Welcome to Houston Astronomical Society

Founded in 1955, Houston Astronomical Society is an active community of enthusiastic amateur and professional astronomers with over 60 years of history in the Houston area. Through education and outreach, our programs promote science literacy and astronomy awareness. We meet on the first Friday of each month at the University of Houston. Membership has a variety of benefits, including access to a secure dark site west of Houston, a telescope loaner program, and much more. Joining is simple; you can sign up online, by mail or in person at a monthly meeting.

"A" is for Asterism

Original article appears in GuideStar May, 2017.

A is for Asterism

by Bram D. Weisman

It was April 10, 2016, a bit past 1:30 a.m. I was star-hoping to a Galaxy cluster, NGC3156 and friends. Star-hoping is not to be confused with star-hopping. The later is a visual stroll that begins on an easy target and proceeds to nearby waypoints leading up to the desired object. The former is desperate meandering around a region of the sky, hoping to stumble across the intended target after a failed attempt at star-hopping.  

Technical note:  
There are three popular search patterns for star-hoping…

  1. Spiral method, best when controlled by a computer
  2. Strip method, also best when controlled by a computer
  3.  Spastic method, best I can muster on my own

Anywho, there I was cruising the sky in my spastic search pattern when I saw something cool.  Five stars, neatly arranged in a kind of an inverted V, well more like an A to be precise.  There were other stars in the field, but these five were close enough in magnitude to strike me as a set, though they actually vary significantly in distance to earth.  The first thing that came into my mind was “Eiffel Tower”.  More on that later.  I wanted to know what this object was, so I checked the coordinates on my Synscan controller.  Even though I was star hopping, earlier I did do a Go-To star alignment to ensure good tracking and to bail me out of trouble.  ;-).  So my Synscan coordinates should have been good.  I also put a “skymark” into SkyTools for me to research at home.  I was able to see the Asterism perfectly rendered in SkyTools.

click read more button


Asterisms - Coat Hanger, Collender 399

By: Steve Goldberg

Asterism: a grouping of stars that form a recognizable pattern.


Constellation: Vulpecula

Right Ascension: 19 h, 26 m 12s

Declination: 20o 06’ 00”

Magnitude:  3.6

Size: 60’ (minutes)


The “Coat Hanger” is a group of stars in the constellation Vulpecula, between Cygnus and Sagitta. It is easily located between the star Albireo in Cygnus and the 2 brightest stars in Sagitta: Alpha and Beta. This open cluster has the official names of Collinder 399 (CR 399) and OCL 113 (Open Cluster).

This object is seen easier in binoculars than with a telescope. And is a good object at public outreach events if you use binoculars.                                         




This object was featured on “Astronomy Picture of the Day” on Dec 23, 2008.

Here is a link: https://apod.nasa.gov/apod/ap081223.html

Gulf Coast Weather and Astronomy

Original article appears in GuideStar June, 2017.

by Stephen Jones

On multiple occasions, usually upon hearing how much observing I’ve been able to do in a relatively short time, people have asked me “how do you know it’s going to be clear when you head out to the dark site?”  To be honest, frequently I don’t!  Here on the Gulf Coast, our weather is notoriously volatile. 

In the winter months though, usually clear skies are pretty predictable.  Watch your local weather forecast for a cold front, look at when it’s going to pass, and head to the site the next night (assuming there’s not another front right behind it!). 

Summer is a completely different beast, however.  In summer, the parade of fronts that we see in the winter stays to the north of us, and we are instead treated to a daily cycle of the sun heating the gulf, generating a bunch of storms which then drift over land and dump some rain on us.  These storms are generally quite small in area and isolated.  One time I distinctly remember driving less than a mile from my home to the store, and it wasn’t raining either at my home or the store, but I drove through pouring down rain on the trip… click the read more button

Deep Sky Object of the Month: M101

Original article appears in GuideStar June, 2017.

by Stephen Jones

Object: M101
Constellation – Ursa Major
Type: Spiral Galaxy
Magnitude: 7.9
Discoverer:  Pierre Méchain, 1781
Equipment necessary:  For most observers, at least a 6-inch telescope.

Spiral structure in galaxies was first noted by Lord Rosse when he turned his massive telescopes on M51, the Whirlpool Galaxy; not long after this, he saw the same in M101.  Face-on spirals like M51 and M101 can be among the most interesting galaxies to observe with medium-to-large sized amateur telescopes under a dark sky, as it is easiest to see the spiral arms when the galaxy has its face toward us… click the read more button

Shallow Sky Object of the Month: Mini-Coathanger

Original article appears in GuideStar May, 2017.

by Bill Pellerin

OBJECT: Mini-Coathanger
CLASS: Asterism
MAGNITUDE: 9 – 11 (stars)
R.A.: 16h 28m 42.0s
DEC: +80° 17' 00"
OPTICS NEEDED: A small telescope

You have probably heard of, and seen, the Coathanger asterism (Collinder 399) in Vulpecula. I wrote a ‘Shallow Sky’ article about this object in the June 2007 GuideStar. This time, we’re looking for the Mini-Coathanger, another asterism for which the arrangement of the stars looks like a coat hanger. The first time I looked for the original Coathanger I expected a triangle with a hook at the top of the triangle, but the asterism looks like a straight line of stars with a hook near the middle.

Likewise, the Mini-Coathanger looks like a line of stars with a hook near the middle. You can easily star hop to this asterism as follows:

  • Find the Little Dipper (itself an asterism in Ursa Minor, the
  • little bear). The end of the handle of the Little Dipper is the
  • North Star, Polaris.
  • From Polaris, count two stars in the direction of the bowl.
  • Draw a line from that star to the bowl star.

The asterism is about 1/3 of the distance along this line and about ½ degree away from this line in the direction of the bowl. The asterism is about 20’ (1/3 of a degree) in size and the stars are relatively bright so it should jump out at you... click read more button

Kids Program

Hey, I’ve got kids.  What’s this all about?

To introduce HAS children to the joys of Astronomy via:

  •     Kid friendly, quality instruments under dark skies
  •     With seasoned Astronomers as their mentors
  •     And structured observing programs with a rewarding, positive end goal (certificates and pins)

The Equipment

HAS Online Store

Get Connected!

HAS has begun using RainedOut, a text message service, to communicate late-breaking news about events. Click here to learn more and subscribe!

Night Sky Network