DEAN: WELCOME TO STAR GAZERS.
I'M DEAN REGAS, ASTRONOMER FROM THE CINCINNATI OBSERVATORY.
JAMES: AND I'M JAMES ALBURY, DIRECTOR OF THE KIKA
SILVA PLA PLANETARIUM IN GAINESVILLE FLORIDA.
DEAN AND I OFTEN TALK ABOUT ORION THE HUNTER BUT RARELY DO WE EVER GET TO TALK ABOUT HIS
DOGS, CANIS MAJOR AND CANIS MINOR.
DEAN: THAT’S RIGHT, JAMES!
AFTER ORION WAS STUNG BY SCORPIUS THE SCORPION, HE WAS PLACED IN THE SKY.
HOWEVER, LIKE MOST DOG-LOVERS, ORION WAS LONELY WITHOUT HIS BELOVED
HUNTING DOGS.
SO, ZEUS PLACED HIS DOGS IN THE SKY TO KEEP HIM COMPANY.
LET’S SHOW YOU!
(STOP & DROP – SET TIME TO 8:30 PM, MARCH 11TH )
JAMES: OK, WE HAVE OUR SKIES SET UP FOR ABOUT AN
HOUR AFTER SUNSET, ANY NIGHT THIS WEEK, FACING SOUTH.
HIGH IN THE SKY, YOU’LL SEE THE FAMILIAR STARS OF ORION THE HUNTER.
THE THREE STARS FORMING HIS BELT MAKE HIM EASY TO FIND.
DEAN: TO FIND CANIS MAJOR, USE ORION’S BELT AND
START WITH THE STAR ON THE FAR RIGHT; THAT STAR IS MINTAKA.
THEN DRAW A LINE FROM MINTAKA, THROUGH ANLINAM AND ALNITAK AND KEEP GOING AND YOU’LL RUN
SMACK DAB INTO THE BRIGHTEST STAR IN THE NIGHT SKY.
THAT STAR’S NAME IS SIRIUS.
JAMES: SIRIUS IS THE BRIGHTEST STAR IN THE NIGHT
SKY BECAUSE IT’S RELATIVELY CLOSE TO US.
AT ROUGHLY 8 LIGHT YEARS AWAY, SIRIUS DEFINITELY MAKES ITS PRESENCE KNOWN.
YOU CAN OFTEN SEE SIRIUS TWINKLING BRILLIANTLY IN THE SOUTHERN SKY.
DEAN: THE NAME SIRIUS COMES FROM THE GREEK WORD
FOR “SCORCHING” AND IT’S ACTUALLY A BINARY STAR SYSTEM.
THE COMPANION STAR, SIRIUS-B IS A WHITE DWARF WITH AN ORBITAL PERIOD OF ALMOST 50 YEARS.
SIRIUS-A AND SIRIUS-B HAD THEIR SMALLEST ANGULAR SEPARATION FROM EACH OTHER BACK IN 1993.
THEIR GREATEST ANGULAR SEPARATION WILL HAPPEN BETWEEN 2020 AND 2025.
JAMES: NOW FOR THE OTHER STARS IN CANIS MAJOR.
UP AND TO THE LEFT OF SIRIUS WE HAVE MULIPHEIN, A BLUE-WHITE GIANT STAR 441 LIGHT YEARS FROM
EARTH, AND ON THE OTHER SIDE OF SIRIUS WE HAVE MIRZAM, MIRZAM IS 500 LIGHT YEARS AWAY
AND ITS NAME MEANS “THE ANNOUNCER”, BECAUSE FROM MOST LOCATIONS,
IT RISES JUST A FEW MINUTES BEFORE SIRIUS.
DEAN: JUST TO THE SOUTH AND EAST OF SIRIUS, YOU’LL SEE A SMALL TRIANGLE OF STARS WHICH
MARK THE HIND QUARTERS OF CANIS MAJOR.
THE STAR AT THE TOP OF THE TRIANGLE IS NAMED WEZEN, A YELLOW-WHITE SUPERGIANT ABOUT 1600
LIGHT YEARS FROM US.
JAMES: THIS STAR’S NAME MEANS “THE WEIGHT” AND FOR GOOD REASON.
WEZEN IS MASSIVE!
IT’S 17 TIMES THE MASS OF OUR SUN, OVER 50,000 TIMES AS BRIGHT AND ITS DIAMETER IS
THE SAME AS THE ORBIT OF THE EARTH.
THEREFORE, IF IT TOOK THE PLACE OF
THE SUN IN OUR SOLAR SYSTEM, WE WOULD BE SKIMMING ACROSS ITS SURFACE.
DEAN: JUST TO THE LEFT OF WEZEN WE HAVE THE STAR ALUDRA.
ALUDRA IS EVEN BRIGHTER THAN WEZEN, BUT ONLY HALF IT’S DIAMETER.
ALUDRA IS A BLUE-WHITE SUPERGIANT, SHINING OVER 176,000 TIMES AS BRIGHT AS OUR SUN AND
IS A WHOPPING 2000 LIGHT YEARS AWAY.
JAMES: THE OTHER STAR IN THE TRIANGLE IS ADHARA.
TODAY, ADHARA IS 430 LIGHT YEARS AWAY, BUT ALMOST 5 MILLION YEARS AGO, ADHARA WAS CLOSE
ENOUGH TO THE EARTH TO BE THE BRIGHTEST STAR IN THE NIGHT SKY; DRAMATICALLY OUTSHINING
SIRIUS AND EVEN RIVALING THE BRILLIANCE OF THE PLANET VENUS.
DEAN: ALRIGHT, LET’S NOW TALK ABOUT ORION’S OTHER HUNTING DOG, CANIS MINOR.
JAMES: THIS SHOULD BE EASY.
CANIS MINOR ONLY HAS TWO STARS.
DEAN: WELL, TWO THAT YOU CAN SEE FROM MOST MAJOR CITIES.
BELIEVE IT OR NOT, THIS TINY CONSTELLATION HAS OVER 50 STARS!
JAMES: NO WAY!
DEAN: YES, WAY…
NOW GRANTED, MANY OF THOSE STARS ARE DIMMER THAN 4TH MAGNITUDE.
NEVERTHELESS, THEY’RE UP THERE.
JAMES: TO FIND CANIS MINOR, TAKE ORION’S SHOULDER STARS BELLATRIX AND BETELGEUSE AND
DRAW A LINE TOWARD THE EAST AND YOU’LL RUN INTO THE TWO STARS PROCYON AND GOMEISA.
PROCYON IS THE BRIGHTER OF THE TWO AND IS ONLY 11 LIGHT YEARS FROM US.
DEAN: GOMEISA IS 162 LIGHT YEARS AWAY AND IS 195 TIMES AS BRIGHT AS OUR SUN WITH
A SURFACE TEMPERATURE OF OVER 20,000 DEGREES FARHENHEIT.
JAMES: WOW!
20,000 DEGREES?!
I GUESS YOU COULD SAY CANIS MINOR IS A REALLY HOT DOG!
HEHEHE!
DEAN: ANYWAY…
GET OUTSIDE TONIGHT AND CHECK OUT ORION’S TWO HUNTING DOGS IN ALL THEIR CELESTIAL SPLENDOR.
JAMES: IT’S EASY TO DO WHEN YOU…
BOTH: KEEP LOOKING UP!