Seeing Stars with James Wooten: Last Chance for Winter Constellations in April

Starmap April

Jupiter is now high in the east-southeast at dusk. It outshines all stars we ever see at night, so you can’t miss it. 

Mercury is visible just after sunset this month. Face west at twilight, and look low in the sky over the point where the sun sets. Mercury isn’t as brilliant as Venus or Jupiter, but it easily outshines the stars near it in the sky, so it’s not too hard to find. 

Mars is in the south-southwest at dawn. Noticeably reddish in tint, Mars continues to brighten each day until its opposition in May. It has now surpassed nearby Saturn in brightness.

Saturn is in the south-southwest at dawn, above the distinctive pattern of Scorpius, the scorpion. Mars remains close to Saturn this month.

Venus is becoming lost in the sun’s glare. Already, it doesn’t rise until deep into morning twilight, and Venus continues to approach the sun all month.

April is the last month to see the set of brilliant winter stars which now fill the western evening sky. Dazzling Orion is in the southwest at dusk. His three-starred belt is halfway between reddish Betelgeuse and bluish Rigel. Orion’s belt points rightward to Aldebaran in Taurus the Bull. To Orion’s upper left are the twin stars Castor and Pollux, marking the heads of Gemini, the Twins. You can find Sirius, the brightest star we ever see at night, by drawing a line from Orion’s belt towards the left. Forming a triangle with Sirius and Betelgeuse is Procyon, the Little Dog Star. 

Joining the winter stars are stars of spring rising in the east. Look for Leo, the Lion at dusk. Ursa Major, the Great Bear, which includes the Big Dipper, is high above the North Star on spring evenings. Extend the Big Dipper’s handle to ‘Arc to Arcturus’ and then ‘speed on to Spica’. There are fewer bright stars in this direction because of where the plane of our galaxy is in the sky. The area of sky between Gemini and Taurus and over Orion’s head is the galactic anticenter, which means that we face directly away from the galactic center when we look in this direction. Those bright winter stars setting in the west are the stars in our galactic arm, right behind the sun. On the other hand, if you look at the sky between Ursa Major, Leo, Virgo, and Bootes, you’re looking straight up out of the galactic plane, towards the galactic pole. There are fewer stars in this direction.

Moon Phases

Moon Phases in April 2016:

New: April 7, 6:24 a.m.

First Quarter: April 13, 10:59 p.m.

Full: April 22, 12:24 a.m.

Last Quarter: April 29 10:29 p.m.

On most clear Saturday nights at the George Observatory, you can hear me do live star tours on the observation deck with a green laser pointer. If you’re there, listen for my announcement. 

Clear Skies!

The Dome is Done! Planetarium renovation moving ahead right on schedule

The Burke Baker Planetarium and Friedkin Theater renovation project reached a milestone this week, and we at the museum are brimming with anticipation!

Okay. That’s an understatement. When we first heard the news, we all ran around screaming, “The dome is finished! The dome is finished!” That’s what really happened.

The dome is indeed complete, and it was no basic DIY endeavor. The Houston Museum of Natural Science’s Astronomy department budgeted an hour for the installation of each of the 197 panels installed. The old screen was removed and replaced first with support structures and next with the new screen, piece by piece, snugly tucked into place.

Dome Complete

In a 360-degree shot, the new domed screen over the Friedkin Theater in the Burke Baker Planetarium looks like a giant cue-ball.

It’s a painstaking process, according to Planetarium Producer Adam Barnes, the man behind our 360-degree custom-made films. He’s working on a time-lapse photo record of the installation that should be available on social media in the next couple of weeks. Once the old screen was gutted and recycled, Barnes explained, project crews shot 16 anchor bolts into the primary structure of the dome, then got to work on its “rib cage,” the support structure that holds the curved screen. The lowest-hanging portion was built first, then raised into place using come-alongs and chained to the anchor bolts at about 20 degrees. The front of the support structure is about two feet off of the ground at the front of the theater and about 20 feet in the back, giving the new dome its aesthetically pleasing tilt. Once the bottom rung was installed, the crew worked in a upward to the center of the dome, installing one rung at a time until the last circular piece was set in place at the top.

PlanetSupport

With the old screen recycled, the next step is unpacking the scaffolding!

“If you imagine a globe, and the lines of latitude and longitude it’s divided into, that’s what the support structure looks like,” Barnes said. “Each little square gets smaller and smaller and more curved until you get to the center, which is a circle.”

With the bones of the theater set, each white panel was raised and placed, carefully measured and marked for size, then taken back down for shaping. The panels ship separately, pre-painted to a specific color rated to 45 percent reflectivity, perforated to make installing the rivets easier, and oversized for the tightest fit possible. Once each panel was measured, it was clamped onto a curved workbench and whittled down into the perfect shape, then re-hung into its final position.

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One by one, the panels are installed with careful measuring and alignment.

“Then they go on to the next panel,” Barnes said. “Each rivet is placed into one of the perforations, so you can’t see how it’s mounted. It’s flush, and they put a little bit of paint over the tiny metal rivet so it blends in very nicely.”

One by one, the panels were installed around and all the way to the top of the dome in much the same fashion as the supports underneath them. The result is a smooth, seamless screen specially designed for domed projections. While most flat-screen theaters have a reflectivity of between 60 and 70 percent (a mirror would reflect 100 percent of light projected onto it), the dome theater’s lower rating actually allows the image to become sharper, though it may not bounce as much light back into the eyes of viewers.

Planet1

“For a dome, you’re shining projectors in front of you but also behind you,” Barnes said. “It’s like looking at an image on a nice, big TV projector screen in front of you and then opening the windows behind you so you can’t see the screen anymore. We call it cross-talk, when the light bouncing off the screen behind you ends up washing out the image in front of you.”

The interference of cross-talk is simply eliminated with a less-reflective screen, maximizing the power of each of the 50 million unique pixels pouring from the Evans & Sutherland Digistar 5 laser projection system. And with the tilt of the dome, guests receive a theater-like experience we’re sure they’ve never seen before.

Planet2

Mark on your calendars the grand opening of the newly renovated Burke Baker Planetarium and Friedkin Theater March 11. Don’t miss the show! Be the first to see the brightest planetarium in the world in action!

Author’s note: All photos by Adam Barnes.

Making the Stars: A Brief History of the Burke Baker Planetarium

In July of 1964, the Houston Museum of Natural Science opened its new museum in Hermann Park with modest exhibit space and the Burke Baker Planetarium. A state-of-the-art Spitz Space Transit Planetarium dominated the theater’s center with its flat floor and a few slide projectors. Two star balls connected by cages, swinging in a yoke, generated the moving stars and planets. All programs were live star tours.

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That year the Houston Independent School District began sending students to the Burke Baker Planetarium. In the last 50 years, over a million HISD children have explored the starry night in an experience reaching every HISD student at least once.

For an idea of what the planetarium experience was back in the 1970s, take a look at my first Burke Baker Planetarium brochure. The brochure was a 3-fold with the front and back cover shown below. The address was 5800 Caroline Street. When you called for reservations, you only used seven digits. The museum was free, but the planetarium cost $1 for adults and 50 cents for children. We did two or three shows a day plus morning school shows and thought we were busy. Now we do 13 to 16 shows each day. Notice the map. The passage between the planetarium and the tiny museum was a glassed-in breezeway.  

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Inside the brochure was a description of the planetarium experience. Burke Baker’s gift has now brought the astronomy experience to more than 7.5 million people, including all upper elementary students in the Houston Independent School District since 1965.  

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Below is the fold over section showing our new Margaret Root Brown Telescope, which is still behind my office on the third floor. We need an access across the roof to open it up to the public once again as well as realuminizing of the mirror. The telescope tracked the sun automatically and sent a live image to the planetarium and the Energy Hall in the lower level. We created five new shows each year, but they were much easier to produce than the two new shows we do now. 

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In 1988, the Burke Baker Planetarium was one of the first in the world to go digital. In a capital campaign that funded the Wortham Giant Screen Theatre, the planetarium’s Friedkin Theater became a space simulator with an Evans & Sutherland Digistar 1, the world’s first digital planetarium projection system.

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In 1998, a decade later, the Burke Baker Planetarium was first in the United States and second in the world to install a Digital Sky full-dome digital video projection system. This dynamic immersive environment was funded by a grant from NASA through Rice University. Now the planetarium could offer full-dome animations and movies with a new slightly tilted dome and seats. The planetarium’s Cosmic Mysteries and Powers of Time were among the first full dome digital films produced.

Eighteen years later, the Friedkin Theater of the Burke Baker Planetarium becomes the most advanced True 8K planetarium in the world. On March 11, HMNS will unveil an overhauled theater featuring an all-new, tilted, seamless projection dome and the main attraction, the Evans & Sutherland Digistar 5 digital projection system. This cutting-edge system brings the highest resolution, the brightest colors, and the most advanced spatial imaging technology on the market to the planetarium, restoring its status as best in the world.

Editor’s note: Keep your eyes peeled for more details about the Planetarium renovation on social media, Facebook, Instagram, Twitter, and right here on our BEYONDbones blog. Throughout the month of February and early March, we’ll be posting the latest information about the project until the grand opening March 11. 

Go Stargazing! September Edition

Venus and Mars have left Saturn behind in the night sky (check out my earlier blog on the position of the planets). You can spot the star Spica in between Mars and Venus during this time of year. (Spica is similar to Mars in brightness and closer to Venus than to Mars). 

 Cloud structure in The Venusian atmosphere,
revealed by ultraviolet observations

September is the last full month to observe Venus at dusk. That’s because Venus has by now come around to Earth’s side of the sun on its faster, inner orbit.  Thus, Venus now begins to overtake the Earth, passing between the Earth and sun on October 29.  We’ll therefore see Venus shift farther to the left of Mars and then drop down below it.  In October, Venus exits the evening sky quite quickly as it shifts back towards the sun.  September and October 2010 is an excellent period for observing Venus’ crescent phase in telescopes.  Anytime Venus is on our side of the sun, more of its night side faces us, resulting in a crescent like appearance when magnified.

Saturn is far to the lower right of Venus and Mars as you face west at dusk.  You’ll need a horizon clear of tall buildings and trees to see it before it sets.  You’ll also need to look early in the month, as Saturn is practically behind the sun by month’s end.  

Jupiter dominates this month’s skies.  On Tuesday morning, September 21, Earth aligns with the sun and Jupiter, bringing Jupiter to opposition (because the sun and Jupiter are then on opposite sides of the Earth).  On the night of September 20-21 we see Jupiter rise at sundown and set at sunup—Jupiter is up literally all night long.  During the whole month, though, Jupiter is visible virtually the whole night.  It outshines all stars in the sky, so it’s easy to find.  Face east in late evening or south southwest at dawn to see it.  The planet Uranus is less than one degree above Jupiter this month; the two planets are closest on September 18.

The Big Dipper is setting in the northwest at dusk; you now need a horizon clear of trees and tall buildings to get a good look at it. You can extend the curve of its handle to ‘arc to Arcturus’, which is in the west at dusk tonight.  Arcturus, by the way, is the fourth brightest star we ever see at night, but the brightest one Americans ever see on a September evening.

As the Dipper gets lower, look for five stars in the shape of an ‘M’ directly across the North Star from the Big Dipper’s handle.  This is Cassiopeia, the Queen—the ‘M’ is the outline of her throne.  Her stars are about as bright as the North Star and the stars of the Big Dipper, so she’s not too hard to find. 

星空下的汗腾格里峰 / Mt. Khan Tengri under Galaxy
Creative Commons License photo credit: livepine

High overhead, look for the enormous Summer Triangle, consisting of the stars Deneb, Vega, and Altair.   This triangle was up all night long from June to early August, hence its name.  Scorpius, the Scorpion, is in the southwest at dusk.  Sagittarius, the Archer, known for its ‘teapot’ asterism, is to its left.  Between these two star patterns is the center of our Milky Way—the brightest part of that band as wee see it.  On a cloudless night far from the big city, see if you notice the Milky Way glow near the ‘teapot’ of Sagittarius. 

Look for the Great Square of Pegasus rising in the east.  The vast stretch of sky under Pegasus is largely devoid of bright stars—ancients called this the ‘Celestial Sea”. 

Moon Phases in September 2010:

Last Quarter                  September 1, 12:22 am, September 30, 10:52 pm

New Moon                       September 8, 5:29 am

1st Quarter                     September 15, 12:49 am 

Full Moon                        September 23, 4:18 am

At 10:13 pm on Wednesday, September 22, the sun is directly overhead at the equator.  As a result, everyone on earth has the same amount of daylight and the same amount of night.  That’s why it is called the equinox (‘equal night’ in Latin).  In the Northern Hemisphere, we’ve seen the days get a little shorter and the midday Sun a little lower each day since June 21.  For us, the season changes from summer to fall at the equinox.  In the Southern Hemisphere, people have seen the days lengthen and the midday Sun get a little higher each day since June.  For them, the season changes from winter to spring.