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SIG AstroImaging meetup tonight Monday 7pm

Phoenix Astronomical Society

Explore the UniverseTogether

Join one of Arizona's most active astronomy communities for observing, astrophotography, education, and discovery.

Phoenix has been looking up since 1948. And for nearly eight decades, whenever someone paused to wonder what was shining overhead, a member of this club was there beside a telescope, ready to explain what they were seeing and inspire the next generation of skywatchers.

We're a 501(c)(3) nonprofit of beginners, backyard observers, astrophotographers, and lifelong amateurs. The telescopes are a means to an end; the point is the people around them.

Astronomy Picture of the Day

Courtesy of NASA's Astronomy Picture of the Day.

Cosmic Latte: The Average Color of the Universe

2026-09-28

Cosmic Latte: The Average Color of the Universe

What color is the universe? More precisely, if the entire sky were smeared out, what color would the final mix be? This whimsical question came up when trying to determine what stars are commonplace in nearby galaxies. The answer, depicted here, is a conditionally perceived shade of beige. In computer parlance: # FFF8E7. To determine this, astronomers computationally averaged the light emitted by one of the larger samples of galaxies analyzed: the 200,000 galaxies of the 2dF Galaxy Redshift Survey. The resulting cosmic spectrum has some emission in all parts of the electromagnetic spectrum, but a single perceived composite color. This color has become much less blue over the past 10 billion years, indicating that redder stars are becoming more prevalent. In a contest to better name the color, notable entries included skyvory, univeige, and the winner: cosmic latte.

Read the full description on APOD ↗

© Karl Glazebrook, Ivan Baldry, JHU, Robert Nemiroff (MTU), Jerry Bonnell (UMCP)

What Our Members See

NASA isn't the only one with a picture of the day — PAS members shoot the Milky Way, nebulae, and the Sun from right here in Arizona.

The Milky Way arching over a desert mountain silhouette
The Milky Way — Kris Mlak
IC 1848, the Soul Nebula, in red and teal emission gas
The Soul Nebula — Richard Sauerbrun
A hydrogen-alpha close-up of a solar prominence
The Sun — Mark Johnston
LDN 541, a dark nebula in Cepheus threading a dense star field
LDN 541 — Caleb Sexton

Upcoming Events

Meetings, star parties, and workshops happen regularly throughout the year.

Monthly Meeting

Our Lecture Series meeting, with a guest speaker and club updates.

Public Star Party

Free, open-air observing — bring your own gear or just look through ours.

Telescope Workshop

Can't find anything in your telescope? Bring it and we'll help.

A PAS member holding out a meteorite for visitors to touch at an outreach event

A PAS Star Tour is more than a look through a telescope—it's a guided journey through the night sky.

Every telescope is staffed by a knowledgeable PAS volunteer who helps visitors discover planets, galaxies, nebulae, and star clusters while explaining what they're seeing. If clouds roll in, our meteorites, displays, and presenters ensure there's still plenty to explore and enjoy.

Bring PAS to Your Group

Why Join PAS

Concrete reasons members stick around — not just a meeting on the calendar.

Monthly Lecture Series

Guest speakers and member talks covering observing, astrophotography, and the latest research.

Telescope Workshops

Free, hands-on help choosing, setting up, and getting the most out of your own telescope.

Star Tours Outreach

Bring PAS telescopes and presenters to your school, scout troop, or community group.

Group Trips

Members-only excursions, like private tours of Lowell Observatory in Flagstaff.

A Club Since 1948

Nearly eight decades of bringing Arizona’s skies to students, families, and lifelong astronomers.