About Us

The Grand Traverse Astronomical Society is a nonprofit organization dedicated to to education and enjoyment of the night sky. Established in 1982, the GTAS has about 30 members from the Traverse City and the Grand Traverse area of northern Michigan. Meetings are held on the first Friday of every month beginning at 8 p.m. at Northwestern Michigan College's Joseph H. Rogers Observatory, though the August meeting is preempted by the annual picnic at another location.

Guests are always welcome to our meetings.

Over 750 attended the society sponsored Comet Hyakutake Watches March 23, and 24th, 1996. The farthest traveler came from Detroit to enjoy the dark skies and the spectacular comet through many telescopes. Comet Hale-Bopp attracted approximately 1,400 during the three scheduled viewing nights that were clear.

We've hit the road, so to speak, with outreach beyond the NMC Observatory since 2007. Since 2011 we've held monthly star parties at Sleeping Bear Dunes National Lakeshore from April to October with additional eclipse and meteor shower watches. We bring our telescopes and exhibits to several festivals around the area along with Friday Night Live in Traverse City. Since 2010 the society has been hosting monthly star parties at the Sleeping Bear Dunes National Lakeshore, and beginning in 2016 at the Arcadia Dunes.

The GTAS belongs to the International Dark-Sky Association and participates in Project Astro.

We also participate in the annual International Observe the Moon Night.

This year it was part of the Sleeping Bear Dunes National Lakeshore virtual Star Party held September 25th.

Upcoming Meetings and Outreach Events

Note that outdoor events are held weather permitting

Due to the Coronavirus (COVID-19) GTAS meetings and star parties at the NMC Observatory will be held virtually via Zoom until further notice.

October ? (No later than the 16th)

We are hoping to set up a Sleeping Bear Dunes virtual Star Party. Keep checking this space.

Friday November 5, 2021

8 pm EDT (UT – 4 hours): Virtual monthly meeting

9 pm EDT (UT – 4 hours): Virtual Star Party

Check here often for other events that may pop up during the month.


These articles are distributed by NASA Night Sky Network

The Night Sky Network program supports astronomy clubs across the USA dedicated to astronomy outreach

Two Articles: Still relevant this month, Corner the Great Square of Pegasus and Catch Andromeda Rising

Corner the Great Square of Pegasus

David Prosper

The Summer Triangle may be the most famous seasonal star pattern, but during early August evenings another geometrically-themed asterism rises: the Great Square of Pegasus. This asterism’s name is a bit misleading: while three of its stars - Scheat, Markab, and Algenib - are indeed found in the constellation of the winged horse Pegasus, its fourth star, Alpheratz, is the brightest star in the constellation Andromeda!

August evenings are an excellent time to look for the Great Square, as it will be rising in the east after sunset. If not obvious at first, wait for this star pattern to rise a bit above the murky air, and remember that depending on your point of view, it may appear more like a diamond than a square. Look for it below the Summer Triangle, or to the southeast of nearby Cassiopeia at this time. As the Great Square rises in prominence during autumn evenings, it becomes a handy guidepost to finding more constellations, including some of the dimmer members of the Zodiac: Aries, Pisces, Aquarius, and Capricornus. Like the Summer Triangle, the Great Square of Pegasus is also huge, but Pegasus itself is even larger; out of the 88 constellations, Pegasus is 7th in size, and feels larger as the stars in its neighboring constellations are much dimmer.

There are many notable deep-sky objects found within the stars of Pegasus - ranging from easily spotted to expert level targets - making it a great constellation to revisit as your observing skills improve. Notable objects include the densely-packed stars of globular cluster M15, a great first target. The potential “Milky Way look-alike” galaxy NGC 7331 is a fun target for more advanced observers, and expert observers can hop nearby to try to tease out the much dimmer interacting galaxies of Stephan’s Quintet. A fascinating (but extremely difficult to observe) object is a gravitationally-lensed quasar famously known as the Einstein Cross. Pegasus has quite a storied history in the field of exoplanet research: 51 Pegasi was the first Sun-like star discovered to be host to a planet outside our solar system, now officially named Dimidiam.

While observing Pegasus and its surroundings, keep your eyes relaxed and ready to catch some Perseids, too! August 2021 promises an excellent showing of this annual meteor shower. The crescent Moon sets early on the evening of the shower’s peak on August 11-12, but you can spot stray Perseids most of the month. If you trace the path of these meteors, you’ll find they originate from one point in Perseus - their radiant. Giant planets Jupiter and Saturn will be up all evening as well. Look south - they easily stand out as the brightest objects in the faint constellations Aquarius and Capricornus.

Pegasus truly holds some fantastic astronomical treasures! Continue your exploration of the stars of Pegasus and beyond with NASA at nasa.gov.

While the stars of the Great Square of Pegasus are not as bright as those of the Summer Triangle, they still stand out compared to their neighbors, and make a great foundation for exploring this area of the night sky. Note that the brightness of the stars near the horizon is exaggerated in this picture.

Stephan’s Quintet is one of the most famous deep-sky objects in Pegasus. First discovered in 1877, it contains the first galaxy group discovered (which includes 4 of the 5 galaxies making up the Quintet) – and has been studied extensively ever since. One day this group will merge into one supergalaxy! While famous, these galaxies are hard to spot in all but the largest backyard telescopes – but are a favorite target of astrophotographers. Take a virtual flyby of these galaxies with a tour created from Hubble data at: bit.ly/quintetflyby

Credit: NASA, ESA, and G. Bacon, J. DePasquale, F. Summers, and Z. Levay (STScI)


Catch Andromeda Rising

David Prosper

If you’re thinking of a galaxy, the image in your head is probably the Andromeda Galaxy! Studies of this massive neighboring galaxy, also called M31, have played an incredibly important role in shaping modern astronomy. As a bonus for stargazers, the Andromeda Galaxy is also a beautiful sight.

Have you heard that all the stars you see at night are part of our Milky Way galaxy? While that is mostly true, one star-like object located near the border between the constellations of Andromeda and Cassiopeia appears fuzzy to unaided eyes. That’s because it’s not a star, but the Andromeda Galaxy, its trillion stars appearing to our eyes as a 3.4 magnitude patch of haze. Why so dim? Distance! It’s outside our galaxy, around 2.5 million light years distant - so far away that the light you see left M31’s stars when our earliest ancestors figured out stone tools. Binoculars show more detail: M31’s bright core stands out, along with a bit of its wispy, saucer-shaped disc. Telescopes bring out greater detail but often can’t view the entire galaxy at once. Depending on the quality of your skies and your magnification, you may be able to make out individual globular clusters, structure, and at least two of its orbiting dwarf galaxies: M110 and M32. Light pollution and thin clouds, smoke, or haze will severely hamper observing fainter detail, as they will for any “faint fuzzy.” Surprisingly, persistent stargazers can still spot M31’s core from areas of moderate light pollution as long as skies are otherwise clear.

Modern astronomy was greatly shaped by studies of the Andromeda Galaxy. A hundred years ago, the idea that there were other galaxies beside our own was not widely accepted, and so M31 was called the “Andromeda Nebula.” Increasingly detailed observations of M31 caused astronomers to question its place in our universe – was M31 its own “island universe,” and not part of our Milky Way? Harlow Shapley and Heber Curtis engaged in the “Great Debate” of 1920 over its nature. Curtis argued forcefully from his observations of dimmer than expected nova, dust lanes, and other oddities that the “nebula” was in fact an entirely different galaxy from our own. A few years later, Edwin Hubble, building on Henrietta Leavitt’s work on Cepheid variable stars as a “standard candle” for distance measurement, concluded that M31 was indeed another galaxy after he observed Cepheids in photos of Andromeda, and estimated M31’s distance as far outside our galaxy’s boundaries. And so, the Andromeda Nebula became known as the Andromeda Galaxy.

These discoveries inspire astronomers to this day, who continue to observe M31 and many other galaxies for hints about the nature of our universe. One of the Hubble Space Telescope’s longest-running observing campaigns was a study of M31: the Panchromatic Hubble Andromeda Treasury (PHAT): bit.ly/m31phat . Dig into NASA’s latest discoveries about the Andromeda Galaxy, and the cosmos at large, at nasa.gov.

Spot the Andromeda Galaxy! M31’s more common name comes from its parent constellation, which becomes prominent as autumn arrives in the Northern Hemisphere. Surprising amounts of detail can be observed with unaided eyes from dark sky sites. Hints of it can even be made out from light polluted areas. Image created with assistance from Stellarium

While M31’s disc appears larger than you might expect (about 3 Moon widths wide), its “galactic halo” is much, much larger – as you can see here. In fact, it is suspected that its halo is so huge that it may already mingle with our Milky Way’s own halo, which makes sense since our galaxies are expected to merge sometime in the next few billion years! The dots are quasars, objects located behind the halo, which are the very energetic cores of distant galaxies powered by black holes at their center. The Hubble team studied the composition of M31’s halo by measuring how the quasars’ light was absorbed by the halo’s material. Credits: NASA, ESA, and E. Wheatley (STScI) Source: https://bit.ly/m31halo


For Kids: NASA’s Space Place website

The Space Place is a NASA website for elementary school-aged kids, their teachers, and their parents.

It’s colorful!
It’s dynamic!
It’s fun!

It’s rich with science, technology, engineering, and math (STEM) content!

It’s informal. It’s meaty. It’s easy to read and understand. It’s also in Spanish. And it’s free!

It has over 150 separate modules for kids, including hands-on projects, interactive games, animated cartoons, and amazing facts about space and Earth science and technology.

See this month's NASA Night Sky Network article at the bottom of the center panel on this page.

Also check out these two sites for kids: NASA's Climate Kids and NOAA's SciJinks

Bob Moler's Ephemeris contains audio mp3s of current Ephemeris programs; calendars of sunrise, sunset,moonrise and moonset for the Grand Traverse area of Michigan, and other locations in northern Michigan; plus a monthly star chart.

Also Bob's Ephemeris Blog with daily transcripts of and illustrations for his Ephemeris programs on Interlochen Public Radio. Wednesday’s program looks at where the bright planets are along with finder charts.

Northwestern Michigan College's Joseph H. Rogers Observatory

If you'd like to donate

From Article II, B of the Articles of Incorporation of the Grand Traverse Astronomical Society:

The Society shall operate a scientific and educational organization with the goal of increasing interest in, the knowledge and enjoyment of astronomy; cooperate with similar organizations; and cooperate with Northwestern Michigan College to increase the benefit of the college observatory to the community.

As you can see by the statement above the society is inexorably linked to the Joseph H. Rogers observatory. However in the past number of years members have been also taking telescopes out into the community, on sidewalks and street corners, and in the street on Friday Night Live, and to the Sleeping Bear Dunes National Lakeshore. We find that many folks in the area have never been out to the observatory. This way we are going to to the public. And having a huge telescope is really a great attraction, not to mention the superb views of the heavens it will provide.

We have purchased a 25 inch Dobsonian telescope with trailer to use and to take around for our outreach program. We have also purchased two solar telescopes to view the Sun's prominences and chromosphere. We feature a solar viewing time at the Sleeping Bear Dunes before the star parties in June, July and August.

We have recently purchased small telescopes to give to libraries for them to lend out. The first two recipients are Traverse Area District Library and Betsie Valley District Library. Enerdyne of Suttons Bay donated the second telescope..

You may contribute to the fund to help us upgrade and add accessories to the society's telescopes by mailing a check to the GTAS, c/o the society treasurer Gary Carlisle, 1473 Birmley Rd, Traverse City, MI 49686. We are a 501(c)(3) non profit organization. Donations are tax deductible.

Thank You!

Updated: 10/01/21 11:08:47 PM