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 via Zoom the first Friday of each month for the General Membership Meeting and the first Thursday of the month for the Novice Meeting. 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.

July 07, 2022, 7:00PM: Novice Presentation - Via Zoom

"Learn the Lingo: Astronomy From A to Z"

by Debbie Moran

Debbie Moran head shot (2).JPG

Join us on the evening of July 7th for a presentation that will benefit all amateur astronomers. Novice Chairperson Debbie Moran will give a talk entitled, "Learn the Lingo: Astronomy From A to Z". Debbie will go in-depth into astronomical terms that may be unfamiliar, vague or confusing and make them clear and understandable. Many of the terms and concepts she will discuss even seasoned astronomers will find interesting. There is something here for everyone, newbies and veterans alike. And who knows, you might even run across them again. Some of the more obscure terms have been known to pop up in an HAS trivia contest!

July 08, 2022, 6:30PM: July Regular Meeting - IN PERSON and via Zoom

The Lives and Observing Records of William and Caroline Herschel

With Larry Mitchell


Abstract – In the mid 18th century based on the work of Sir Isaac Newton,  it was thought the universe beyond the solar system was unchanging. William Herschel completely changed this theory, along with many more generally accepted ideas.

Without any formal training he established concepts which persisted for the next 100 years and provided the very foundation of today’s astronomical knowledge. This is why today he is known as the “Father of modern astronomy”. Most people have no idea of the huge database Herschel provided, based solely on his visual observations through instruments he built. These were the finest observations the world had seen, up to that time.

Larry is in possession of every scientific paper William Herschel published and will present information not seen elsewhere. We hope you can attend this very informative presentation.


Our Speaker : We are fortunate to have many accomplished members in HAS and one of them is certainly our own Larry Mitchell.  Larry has been a long time member of HAS. He is strictly a visual ‘Star-hopping‘ observer but admits that he greatly appreciates the work provided by imagers. During his observing carreer, Larry has:

- Observed all 2,508 objects Wm Herschel discovered including the ‘nonexistents’.

-Authored the Mitchell Anonymous  catalog, the MAC which consists of 117,300 previously uncatalogued galaxies. 

-Discovered supernova SN1994S.

- Served as Chairman of visual observing programs for the Texas Star Party and for the Stellafane Convention.

- Owned too many telescopes but mainly uses 36-inch and 20 inch Dobsonians, and a 7 inch refractor.

AP Corner June 2022; Finding Your Focus Part 2

By Don Sellesw.jpg

In Part 1 of this article, I described several techniques you could use to manually focus your smartphone or your DSLR used either stand alone or attached to your telescope. Adding an inexpensive Bhatinov mask to the front of your telescope or DSLR lens (yes you can get them that size) makes achieving critical focus using the camera’s live view focusing very doable. This technique can also be used for a dedicated astro-imaging camera on your telescope if you view the focus images as they are downloaded to the computer controlling the camera.

The Bhatinov mask works great, but let’s face it, manual focusing can be a tedious and time-consuming task. When I first started astro-imaging, manual focusing was the norm for me and others like me starting out because the motorized focusers were few, and they were rather expensive. In addition, there was not much software to automate the focusing process and there were no real interface standards to allow computer control of the telescope focuser. So, we learned to focus by hand and by eye. 

Messier Column June 2022

by Jim King


I find myself compelled to once again, give credit where credit is due.  While Charles Messier basks in the glow of his famous catalogue of non-comets, he had help!  During his collaboration with Messier, Pierre Mechain added 25 or 26 objects to Messier’s catalogue (depending on how one looks at M102).

These include Messier’s 63,72,74,75,76,77,78,79,85,94,95,96,97,98,99,100,101, 102(?), 103, 104, 105,106,107,108,109… a sizable addition to Messier’s work.

Pierre Méchain was born in Laon, the son of the ceiling designer and plasterer Pierre François Mechain and Marie–Marguerite Roze. He displayed mental gifts in mathematics and physics but had to give up his studies for lack of money. However, his talents in astronomy were known to Jerome Lelande, for whom he became a friend and proof-reader of the second edition of his book "L'Astronomie". Lalande then secured a position for him as assistant hydrographer with the Naval Depot of Maps and Charts in Versailles, where he worked through the 1770s engaged in Hydrographic work and coastline surveying. It was during this time—approximately 1774—that he met Charles Messier, and apparently, they became friends. In the same year, he also produced his first astronomical work, a paper on an occultation of Aldebaran by the Moon and presented it as a memoir to the Academy of Sciences.

In 1777, he married Barbe-Thérèse Marjou whom he knew from his work in Versailles. They had two sons: Jérôme, born 1780, and Augustin, born 1784, and one daughter. He was admitted to the French Académie des Sciences in 1782, and was the editor of Connaissance des Temps from 1785 to 1792; this was the journal which, among other things, first published the Messier Objects. In 1789 he was elected a Fellow of the Royal Society.

Why the Moon Has Two Faces

By William Sager


Every astronomer knows that the Moon has one side facing the Earth, the near side, and another side, that cannot be seen, the far side. This occurs because the Moon’s rotation exactly matches its orbital period. Until the Space Age, nobody had seen the far side. Starting with the Soviet Union’s Luna 3 in 1959, spacecraft began sending back pictures of the far side and today we have high-resolution images thanks to NASA’s Lunar Reconnaissance Orbiter (LRO). Even a casual glance reveals that the near and far sides appear vastly different (Figure 1). The near side contrasts high-albedo anorthosite highlands with dark basaltic lowland plains named mare by early observers who thought they were seas. (Note: anorthosite is an igneous rock consisting mainly of potassium felspar whereas basalt is an igneous rock rich in iron and magnesium). In contrast, the far side is mostly anorthosite with only a few small, scattered and isolated mare. In a recently published paper in the journal Science Advances, a multi-university team led by Matt Jones of Brown University reported having worked out the reason for the Moon’s two faces.

Why the Stars Shine

By: Don Selle

First published in the October 2012 issue of the Guidestar


“It is reasonable to hope that in the not too distant future we shall be competent to understand so simple a thing as a star.”  Arthur Eddington

“Science is the one human activity that is truly progressive. “ Edwin Powell Hubble

“I can find in my undergraduate classes, bright students who do not know that the stars rise and set at night, or even that the Sun is a star.”   Carl Sagan

Humans are creatures of habit, it’s built into us.  It’s an evolutionary adaptation that enhances our chances of survival in the natural world. We like things to be normal and routine, and for most of us, it takes a lot to change our patterns of behavior and of thought. 

But nothing progresses if it is constant or follows the same patterns over and over again. Because our thought processes follow common, established patterns, we often need a challenge to jolt us into finding a “new normal”, a new way of looking at things. 

Solstice Shadows, Night Sky Network June 2022

by David Prosper


Solstices mark the changing of seasons, occur twice a year, and feature the year’s shortest and longest daylight hours - depending on your hemisphere. These extremes in the length of day and night make solstice days more noticeable to many observers than the subtle equality of day and night experienced during equinoxes. Solstices were some of our earliest astronomical observations, celebrated throughout history via many summer and winter celebrations.


Asterisms – Giraffe

By: Steve Goldberg  (Posted 5/15/2019)

Asterism: a grouping of stars that form a recognizable pattern.
Constellation: Bootes
Right Ascension:  14h 31m 29.0s
Declination: +49o 11’ 16”
Magnitude: 7 to 12         
Size: 25 minutes        
This month’s asterism adds to the list of “animals” as seen in the sky. Houston Astronomical Society member Karla Zielke named the Giraffe asterism. She saw this while observing at the Texas Star Party.


It is located near the border between Bootes and Ursa Major.





The Giraffe can be located at the “top” of a triangle made up of Alkaid η Ursa Major (the end star in the handle of the Big Dipper) and star Nekkar  β Bootes.


It can also be located near NGC 5676.



In a low power eyepiece, you can see the asterism. The bright star at lower left of center is the head, with the front legs being the curve of stars going to the upper right. The hind legs are the triangle of stars to the lower right.


In the same field of view NGC 5676 can be seen.


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