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.

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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.

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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.

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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. 

Seeing Stars with James Wooten: Five planets at dawn, leap day this February!

Star Map

Jupiter is now a late evening object, rising in the east. It rises by 9 p.m. on Feb. 1, and by Feb. 29 it comes up just before 7 p.m., which is during evening twilight. Jupiter comes to opposition on March 8, which is when Earth aligns with Jupiter and the Sun. That is why Jupiter is up all night long in late February and early March.

As dawn approaches this month, Jupiter will still be visible, this time high in the west.  Meanwhile, the four other visible planets will have risen as well. That’s right, February 2016  features all five naked-eye planets at dawn!

Venus is in the southeast at dawn. You can’t miss it, as Venus outshines all the stars we see at night, and in fact outshines everything but the Sun and the Moon.

Mars is in the south at dawn. Noticeably reddish in tint, Mars continues to brighten each day until its opposition next spring. 

Saturn is in the south southeast at dawn, above the distinctive pattern of Scorpius, the scorpion. Mars slowly approaches Saturn this month.

Mercury is the biggest challenge to find. This month, though, Mercury is very close to Venus and to its left. Thus, once you find Venus, the brightest dot to its left is Mercury. 

Mercury is the first planet to leave the gathering as it heads back towards the Sun late this month. The cutoff date of Feb. 20 is somewhat arbitrary, though. It’s better to watch the sky and, using Venus as your guide, see for yourself when is the last day you can still see Mercury before losing it the Sun’s glare. The next to leave is Jupiter, which shifts into the evening sky after opposition. 

Taurus, the Bull, is high in the south. Look for the Pleiades star cluster above reddish Aldebaran. Dazzling Orion, the Hunter, takes center stage on winter evenings.  Surrounding Orion are the brilliant stars of winter. Orion’s belt points down to Sirius, the Dog Star, which outshines all other stars we ever see at night. The Little Dog Star, Procyon, rises with Sirius and is level with Orion’s shoulder as they swing towards the south. To the upper left of Orion’s shoulder is Gemini, the Twins.

Under Sirius and low to the southern horizon this month is a star that most Americans never get to see—Canopus. Representing the bottom (keel) of the legendary ship Argo, Canopus is the second brightest star ever visible at night. Thus, it is clearly noticeable along the southern horizon on February and March evenings. However, you must be south of 37 degrees north to see Canopus rise. (This is the line that divides Utah, Colorado, and Kansas from Arizona, New Mexico, and Oklahoma.)

The sky we see depends on our latitude as well as on the time of night and time of year.  From any given location in our hemisphere, there is an area of the sky around the North Star in which stars never set (circumpolar stars), and an equivalent area around the South Celestial Pole in which stars never rise. The closer you are to the pole, the larger these areas are. The closer you get to the equator, the fewer circumpolar stars there are, but there are also fewer stars that never rise for you. At the equator, no stars are either circumpolar or never visible; all of them rise and set as Earth turns. 

That’s why, down here in south Texas, the Big Dipper sets for a while although it’s always up for most Americans. On the other hand, Canopus, too far south to rise for most Americans, rises for us.

Moon Phases

Moon Phases in February 2016:

Last Quarter: Jan. 31, 9:28 p.m.

New: Feb. 8, 8:39 a.m.

First Quarter: Feb. 15, 1:46 a.m.

Full: Feb. 22, 12:20 p.m.

(February is so short that last quarter Moons occur on Jan. 31 and March 1, but not in February). 

The New Moon of Feb. 8 is the second New Moon after the winter solstice. Accordingly, it marks Chinese New Year. Welcome to the Year of the Monkey!

Monday, Feb. 29, is leap day. This day exists because our normal year of 365 days is too short. The true length of one Earth orbit around the Sun is 365 days and almost 6 hours.  No one wants to begin a year in the middle of a day, however. Therefore, we let the error add up over four years, until it becomes 24 hours, or one whole day, then add that day back to the calendar. Thus, February 29 occurs every four years. 

Almost 6 hours?  Well, alright, the difference between our orbit and our year is actually 5 hours, 49 minutes, and 16 seconds. That makes our system a very slight overcorrection.  To prevent that from adding up, we’ll skip leap day in 2100, 2200, and 2300. 

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!