VEGA, ALTAIR AND DENEB…
OH MY!
JAMES: HEY THERE STAR GAZERS.
I'M JAMES ALBURY, DIRECTOR OF THE KIKA SILVA PLA PLANETARIUM IN GAINESVILLE, FLORIDA.
DEAN: AND, I'M DEAN REGAS, ASTRONOMER FOR THE CINCINNATI
OBSERVATORY.
WERE HERE TO HELP YOU FIND YOUR WAY AROUND THE SKY.
THIS WEEK WE WANT YOU TO KICK BACK AND RELAX UNDER THE STARS
JAMES: SUMMER OFFICIALLY BEGINS AT THE END OF THIS
WEEK AND THOSE WARM EVENINGS ARE PERFECT FOR LYING IN THE GRASS AND
LOOKING UP.
DEAN: THE BRIGHTEST STARS OF THE SEASON ARE OVERHEAD.
JAMES: THERE YOU'LL FIND A TRIANGLE OF THREE CELESTIAL
DAZZLERS - THE STARS OF THE SUMMER TRIANGLE NAMED VEGA, ALTAIR, AND DENEB.
DEAN: AS SUMMER BEGINS, LET'S TAKE A CLOSER LOOK.
DEAN: OKAY WE HAVE OUR SKY SET UP FOR 11PM ANY NIGHT
THIS WEEK FACING EAST.
YOU'LL SEE 3 BRIGHT STARS THAT REALLY STAND OUT.
ITS A TRIANGLE.
ITS RISING IN SUMMER.
SO I'D CALL THAT A SUMMER TRIANGLE.
JAMES: LET'S FOCUS IN ON THOSE 3 STARS, AND FLY IN
FOR A CLOSER LOOK.
DEAN: NO MATTER IF YOU LIVE IN THE COUNTRY OR THE
HEART OF A CITY, YOU SHOULD BE ABLE TO FIND THESE THREE STARS DISTINCTLY IN THE SKY.
WHEN YOU CONNECT THEM WITH LINES THEY FORM A HUGE TRIANGLE OVER 30 DEGREES LONG AND 20
DEGREES HIGH.
JAMES: REMEMBER THE EASY WAY TO MEASURE DEGREES
IN THE SKY?
YOUR FIST AT ARMS LENGTH IS ABOUT 10 DEGREES.
SO SEE IF YOUR SUMMER TRIANGLE IS TWO FISTS HIGH AND THREE
FISTS LONG.
DEAN: THE BRIGHTEST STAR OF THE THREE, AND THE ONE
CLOSEST TO THE ZENITH JUST AFTER SUNSET IS CALLED VEGA.
JAMES: DO I DETECT A SLIGHT BLUE-ISH TINT TO
THIS STAR?
DEAN: YOU SURE DO.
VEGA IS A BLUE-WHITE GIANT STAR AND THIS TELLS US ITS TEMPERATURE.
BLUE IS HOTTER THAN WHITE WHICH IS HOTTER THAN YELLOW.
VEGA IS WELL OVER 16,800 DEGREES FAHRENHEIT ON ITS SURFACE.
MUCH HOTTER THAN OUR 10,000 DEGREE YELLOW SUN.
JAMES: THE SECOND BRIGHTEST STAR IN THE TRIANGLE,
AND THE ONE OFF TO THE RIGHT, IS CALLED ALTAIR.
ALTAIR IS STARK WHITE IN COLOR WITH A TEMPERATURE OF 13,400 DEGREE
FAHRENHEIT.
DEAN: AND THE FAINTEST OF THE THREE, OVER TO THE
LEFT IS CALLED DENEB.
DENEB IS BLUEISH-WHITE - NOT AS BLUE AS VEGA BUT HOTTER THAN ALTAIR.
IT SCORCHES SPACE WITH A SURFACE TEMPERATURE OF ABOUT 14,800 DEGREES.
JAMES: EACH BRIGHT STAR IN THE SUMMER TRIANGLE IS
PART OF ITS OWN CONSTELLATION.
IF I USE MY IMAGINATION (AND SOME HELP FROM THE STAR GAZERS GRAPHICS DEPARTMENT),
I CAN JUST MAKE THEM OUT.
VEGA IS PART OF THE CONSTELLATION LYRA THE HARP.
THE STARS MAKE A TINY PARALLELOGRAM HANGING OFF VEGA.
IN SOME PICTURES OF LYRA THERES A BIRD AROUND THE HARP - SINCE PEOPLE ALSO CALLED THIS A
VULTURE.
DEAN: ALTAIR IS THE EAGLE EYE OF THE CONSTELLATION
AQUILA THE EAGLE.
IF YOU CANT SEE AN EAGLE IN THOSE STARS, YOU'RE NOT ALONE.
BUT AT LEAST YOU KNOW WHERE THE EYE IS.
JAMES: AND DENEB IS THE TAIL STAR OF THE STELLAR
SWAN - THE CONSTELLATION CYGNUS.
OKAY, THAT'S AN EASY ONE TO PICTURE WITH HIS BODY AND LONG, STRETCHED-OUT BEAK.
CYGNUS FORMS A CROSS SHAPE AND IS ALSO CALLED THE NORTHERN CROSS.
DEAN: NOW LETS TALK DISTANCES.
VEGA IS THE BRIGHTEST OF THE THREE STARS BUT IS NOT THE CLOSEST.
THAT HONOR GOES TO ALTAIR WHO IS ONLY 17 LIGHT YEARS AWAY FROM US.
WITH PROFESSIONAL TELESCOPES WE CAN ACTUALLY SEE THAT ALTAIR IS SPINNING RAPIDLY.
IT SPINS SO FAST THAT IT HAS SQUISHED ITS SHAPE TO RESEMBLE A BLUE-WHITE EGG.
JAMES: VEGA IS THE SECOND CLOSEST AT ABOUT
25 LIGHT YEARS AWAY.
THAT MEANS THE LIGHT THAT YOU SEE LEFT VEGA 25 YEARS AGO.
THAT WAS BACK WHEN I HAD HAIR!
DEAN: HA!
DENEB IS NOT ONLY THE FARTHEST OF THE THREE, IT IS PERHAPS THE FARTHEST STAR YOU CAN SEE
WITH THE NAKED EYE.
AT A WHOPPING 3000 LIGHT YEARS AWAY, WE CAN STILL SEE IT AS A BRIGHT STAR.
THAT MEANS DENEB MUST BE HUMONGOUS.
HERE IS A SIDE-BY-SIDE COMPARISON OF THE THREE SUMMER TRIANGLE STARS…
JAMES: WOW-SERS!
DENEB DWARFS THE OTHER TWO.
DEAN: SO GET OUTSIDE UNDER THE SUMMER STARS THIS
WEEK.
JAMES: ENJOY THE WARM SUMMER NIGHTS AND LOOK FOR
THE SUMMER TRIANGLE RISING IN THE EAST.
DEAN: VEGA, ALTAIR AND DENEB SHINE IN THE SKY
AS SUMMER BEGINS.
SO DEFINITELY…
BOTH: KEEP LOOKING UP!