STARS FOR EVERY SEASON
JAMES:
WELCOME TO 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.
WE'RE HERE TO HELP YOU FIND YOUR WAY AROUND
THE SKY.
YOU KNOW,
WE CAN SEE SOME STARS AND CONSTELLATIONS
ALL YEAR ROUND -
LIKE THE BIG DIPPER AND CASSIOPEIA.
JAMES:
WHILE OTHERS ARE ONLY VISIBLE DURING CERTAIN
SEASONS -
LIKE SCORPIUS AND THE SUMMER TRIANGLE.
WHY IS THIS?
DEAN:
LET'S SHOW YOU THE DIFFERENCE BETWEEN CIRCUMPOLAR
AND SEASONAL STARS.
DEAN:
OKAY WE HAVE OUR SKIES SET UP TO ANY NIGHT
THIS WEEK,
FACING NORTH AT 10:30PM.
FIRST, FIND THE BIG DIPPER STANDING ON
ITS SPOON HIGH IN THE NORTHWESTERN SKY.
THESE SEVEN STARS ALSO MARK THE REAR END AND
TAIL OF URSA MAJOR,
THE BIG BEAR.
JAMES:
WE CAN USE THE TWO STARS ON THE END OF
THE SPOON TO POINT US TO POLARIS,
AKA THE
NORTH STAR.
POLARIS MARKS THE END OF THE TAIL OF THE
LITTLE BEAR,
URSA MINOR
DEAN:
OR THE END OF THE HANDLE OF THE
LITTLE DIPPER.
JAMES:
NOW IF YOU CONTINUE THAT LINE FROM THE
BIG DIPPERS HANDLE THROUGH POLARIS,
YOU REACH A CONSTELLATION THAT LOOKS LIKE
THE
LETTER, W.
THIS IS THE BEAUTIFUL CASSIOPEIA THE QUEEN
SITTING ON HER THRONE.
DEAN:
THESE THREE CONSTELLATIONS,
URSA MAJOR,
URSA MINOR, AND CASSIOPEIA ARE VISIBLE IN
THE SKY NEARLY EVERY NIGHT OF THE YEAR.
THE REASON WHY,
IS THAT, AS THE NIGHT ROLLS ON,
THE STARS WILL APPEAR TO ROTATE AROUND A PIVOT
POINT -
NEAR POLARIS.
JAMES:
THIS MOTION IN THE HEAVENS IS ACTUALLY CAUSED
BY THE ROTATION OF THE EARTH.
OUR DAILY SPIN CAUSES STARS TO RISE IN THE
EAST AND SET IN
THE WEST.
BUT IN THE NORTH WE CAN WATCH THE STARS
SPIN A FULL 360 DEGREES WITHOUT GOING BELOW
THE HORIZON.
THAT MAKES THEM
CIRCUM- POLAR STARS.
DEAN:
WOW,
THIS IS MAKING ME DIZZY!
JAMES:
STAY FOCUSED, DEAN!
DEAN:
YES, AND WHEN YOU LOOK AT STARS FARTHER
FROM POLARIS,
THEY SEEM TO MAKE
BIGGER CIRCLES
IN THE SKY.
SO THE FARTHER SOUTH YOU LOOK,
THE LESS EACH CONSTELLATION IS ABOVE THE HORIZON.
JAMES:
AS THE EARTH ORBITS
THE SUN,
OUR PERSPECTIVE ON
THE DISTANT STARS CHANGES.
WHEN WE'RE ON ONE
SIDE OF THE SUN,
LIKE IN WINTER,
WE CAN MORE EASILY SEE CONSTELLATIONS LIKE
ORION AND GEMINI
AT NIGHT.
DEAN:
BUT WHEN WE'RE ON THE OTHER SIDE OF THE SUN,
LIKE IN SUMMER,
WE CAN'T SEE ORION AND GEMINI AS WELL BECAUSE
THE GLARE OF THE SUN IS IN THE WAY.
THOSE CONSTELLATIONS ARE ONLY ABOVE THE HORIZON
DURING THE
DAY TIME.
IN SUMMER WHEN THE NIGHTTIME PART OF THE EARTH
IS POINTED THAT WAY THEN WE CAN BETTER SEE
THE
STAR PATTERNS LIKE SCORPIUS AND THE SUMMER
TRIANGLE.
SO ALL THESE ARE SEASONAL CONSTELLATIONS.
JAMES:
BUT NO MATTER WHAT SEASON IT IS,
WE ALWAYS HAVE A GOOD VIEW TO THE
NORTHERN SKY.
SO WE,
IN THE NORTHERN HEMISPHERE,
CAN VIEW URSA MAJOR, URSA MINOR,
AND CASSIOPEIA ALL
YEAR LONG.
THAT MAKES THEM CIRCUMPOLAR CONSTELLATIONS.
JAMES:
SO NOW THAT WE'RE
IN SUMMER,
LET'S CHECK OUT THE SUMMER TRIANGLE.
LOOK HIGH IN THE EAST AND YOU'LL FIND ITS
THREE BRIGHT STARS.
WE CAN SEE THE BRIGHTEST STAR, VEGA,
IS AT THE TOP,
BRIGHT WHITE ALTAIR IS TO THE RIGHT,
AND DIMMER DENEB IS
TO THE LEFT.
DEAN:
VEGA IS THE BRIGHTEST STAR IN THE CONSTELLATION
LYRA
THE HARP,
ALTAIR IS THE EAGLE EYE OF AQUILA THE EAGLE,
AND DENEB IS THE TAIL
OF CYGNUS THE SWAN: THREE GREAT SUMMER CONSTELLATIONS
IN ONE BIG TRIANGLE.
JAMES:
ANOTHER EASY-TO-FIND SUMMER CONSTELLATION
IS LOW IN THE
SOUTHERN SKY.
THERES SCORPIUS THE SCORPION.
YOU WON'T NEED TO STRAIN YOUR IMAGINATION
TO SEE A SCORPION IN THE LONG FISHHOOK OF
STARS THAT MAKE HIS
TAIL AND STINGER.
DEAN:
THE BRIGHTEST STAR IN SCORPIUS IS A BEAUTIFUL,
RED STAR ANTARES.
ANTARES MEANS RIVAL OF MARS BECAUSE ITS COLOR
IS SIMILAR TO THAT OF THE RED PLANET.
A STRING OF FAINTER NIGHT LIGHTS CURL JUST
ABOVE THE HORIZON AND END AT THE SCORPIONS
STINGER-STARS:
SHAULA AND LESATH.
YOU CAN THE STARS OF SCORPIUS EVERY SUMMER
EVENING.
JAMES:
SO GET OUTSIDE TONIGHT AND SEE HOW THE STARS
MOVE OVER THE NIGHT.
IT MIGHT TAKE A FEW HOURS (OR DAYS)
BUT YOU'LL NOTICE THE DIFFERENCE BETWEEN THE
CIRCUMPOLAR AND SEASONAL CONSTELLATIONS.
DEAN:
SAY HI TO OUR OLD FRIENDS,
URSA MAJOR,
URSA MINOR,
AND CASSIOPEIA.
AND THEN YOU CAN CELEBRATE SUMMER BY SPOTTING
THE SUMMER TRIANGLE AND THE SCORPION.
BOTH:
KEEP LOOKING UP!