DEAN:
HEY THERE STAR GAZERS.
IM DEAN REGAS, ASTRONOMER FROM THE CINCINNATI
OBSERVATORY.
JAMES:
AND I'M JAMES ALBURY, DIRECTOR OF THE KIKA
SILVA PLA PLANETARIUM IN GAINESVILLE, FLORIDA.
AND WERE HERE TO HELP YOU FIND YOUR WAY AROUND
THE SKY.
DEAN:
STARS ARE NOT ALWAYS WHAT THEY SEEM.
MOST STARS IN THE SKY ARE REALLY TWO, THREE,
OR MORE STARS ORBITING EACH OTHER.
MANY STARS WILDLY FLUCTUATE IN BRIGHTNESS.
THEY'RE ALL DIFFERENT COLORS AND TEMPERATURES.
SOME ARE NEWLY BORN AND OTHERS ARE NEARING
THEIR DRAMATIC DEMISE.
JAMES:
THIS WEEK WERE GOING TO LOOK AT THREE STARS
IN THE FALL SKY WITH HIDDEN SECRETS.
THE FIRST STAR IS ACTUALLY TWO BEAUTIFULLY
COLORED STARS IN A SMALL TELESCOPE.
DEAN:
THE SECOND STAR WILL MAKE YOUR HEAD SPIN.
JAMES:
AND THE THIRD IS A LONELY STAR WITH A FUNNY
NAME THAT GAVE ASTRONOMERS A BIG PLANETARY
SURPRISE.
AS OUR TELESCOPES GET BETTER AND BETTER, WERE
UNCOVERING THE MYSTERIOUS NATURE OF STARS
TRILLIONS OF MILES AWAY.
DEAN:
LET US INTRODUCE YOU TO THE STARS ALBIREO,
ALTAIR AND FOMALHAUT.
JAMES:
OKAY, WE HAVE OUR SKIES SET TO 10:00 P.M.
THIS MONTH LOOKING WEST.
THE MOST PROMINENT FEATURE IS THE SUMMER TRIANGLE.
LOOK FOR THREE REALLY BRIGHT STARS IN THE
SKY AND YOU'VE FOUND IT!
DEAN:
THE THREE STARS ARE CALLED VEGA, ALTAIR, AND
DENEB.
JAMES:
NOW DENEB IS SUPPOSED TO BE THE BRIGHT TAIL
OF THE CONSTELLATION CYGNUS THE SWAN BUT WERE
GOING TO ZOOM IN ON THE FAINTER HEAD STAR
VISIBLE WITHIN THE SUMMER TRIANGLE.
DEAN:
THIS IS THE STAR CALLED ALBIREO AND ITS ONE
OF MY FAVORITE STARS TO LOOK AT WITH A SMALL
TELESCOPE.
DEAN:
WHEN YOU LOOK CLOSER AT ALBIREO, YOU FIND
ITS REALLY A DOUBLE STAR - TWO STARS ORBITING
EACH OTHER.
THE BIGGER ONE IS
ORANGE IN COLOR AND THE SMALLER ONE IS BRILLIANT
BLUE.
THE CONTRASTING COLORS MAKE A COOL AND HOT
SIGHT TO SEE - BECAUSE THIS TELLS US THEIR
CONTRASTING TEMPERATURES.
THE BLUER, THE HOTTER.
THE ORANGER,
THE COOLER.
THEY'RE LIKE TWO BEAUTIFUL, SPARKLING JEWELS
IN THE NIGHT SKY.
JAMES:
NOW LET'S GET BACK TO THE STAR ALTAIR AND
IT'S HIDDEN SECRET.
ALTAIR LOOKS LIKE ANY ORDINARY BRIGHT WHITE
STAR, BUT IT IS ONE OF THE CLOSER STARS TO
US, AT ONLY 17 LIGHT
YEARS AWAY.
DEAN:
AND BECAUSE ITS RELATIVELY CLOSE, ASTRONOMERS
COULD UNCOVER ALTAIRS SECRET - ITS MIND-BOGGLING
ROTATIONAL RATE.
JAMES:
MEANING IT SPINS
REALLY FAST!
DEAN:
OUR SUN SPINS AS WELL.
THE SUN ROTATES ABOUT 2 KILOMETERS PER SECOND
AT ITS EQUATOR SO IT TAKES ABOUT
25 DAYS FOR THE SUN
TO SPIN ONCE.
NOW LETS COMPARE OUR SUN TO ALTAIR.
ALTAIR IS ALMOST TWICE AS BIG AS THE SUN AND
SHINES 11 TIMES BRIGHTER.
BUT HOLD ONTO YOUR SEATS, THIS STAR SPINS
SUPER-FAST!
AT THE EQUATOR, ALTAIR ROTATES AT ABOUT 286
KILOMETERS PER SECOND.
THAT MEANS THAT THE ENTIRE STAR SPINS ONCE
EVERY 9 HOURS!
JAMES:
THIS UNBELIEVABLE ROTATIONAL VELOCITY HAS
ACTUALLY AFFECTED THE SHAPE OF THIS STAR.
INSTEAD OF A SPHERE, ALTAIR IS SQUISHED AT
THE POLES AND BULGES AT THE EQUATOR.
THE ENTIRE MASS OF THE STAR HAS SHIFTED AND
HAS LEFT ALTAIR LOOKING LIKE A RAPIDLY
SPINNING EGG.
DEAN:
NEXT, LETS LOOK SOUTH AT 10:00 P.M.
WHERE YOU'LL SEE ONLY ONE BRIGHT STAR.
THIS IS FOMALHAUT THE BRIGHTEST STAR IN THE
CONSTELLATION OF PISCIS AUSTRALIS, OR THE
SOUTHERN FISH.
JAMES:
WITH A LITTLE IMAGINATION YOU CAN MAKE OUT
A GOLDFISH SHAPE IN THESE STARS WITH FOMALHAUT
AS ONE BEADY EYE...
CUTE.
DEAN:
FOMALHAUT IS A
BLUE-WHITE STAR
25 LIGHT YEARS AWAY, MAKING IT ANOTHER CLOSE
TARGET TO OBSERVE WITH THE BEST TELESCOPES.
IN 2004 ASTRONOMERS DETECTED A DUST RING AROUND
FOMALHAUT.
JAMES:
WE CALL IT PROTO-PLANETARY DEBRIS.
DEAN:
OR JUST A BIG RING OF STUFF, AND EVERYONE
GOT EXCITED.
THIS WAS THE KIND OF STUFF THAT MIGHT HARBOR
A PLANET OR EVEN A WHOLE SOLAR SYSTEM.
JAMES:
AND THEN IN 2008, ASTRONOMERS CAUGHT THE FIRST
VISIBLE-LIGHT IMAGE OF A PLANET ORBITING AROUND
ANOTHER STAR - ORBITING AROUND FOMALHAUT.
YOU HAVE TO REALLY SQUINT, BUT THERE IT IS.
JAMES:
SO CHECK OUT FOMALHAUT TONIGHT, THE LONE STAR
IN THE SOUTH.
DEAN:
THATS NOT SO LONELY AFTER ALL.
JAMES:
FIND RAPIDLY ROTATING ALTAIR IN THE WESTERN
SKY ON THE LEFT SIDE OF THE SUMMER TRIANGLE.
DEAN:
AND DONT FORGET TO TRAIN YOUR TELESCOPES ON
ALBIREO TO DISCOVER ITS SECOND SUN.
WHEN YOU LOOK AT THE STARS ABOVE WHO KNOWS
WHAT OTHER HIDDEN SECRETS YOULL DISCOVER WHEN
YOU
BOTH:
KEEP LOOKING UP!