WPBT2's Star Gazers

Episode #12-37 "The False Dawn of Omar Khayyam"
Air Dates September 10 - September 16, 2012

DEAN: Hey there Star Gazers. I’m Dean Regas, astronomer for the Cincinnati Observatory.

JAMES: And I’m James Albury, Director of the Kika Silva Pla Planetarium in Gainesville, Florida. Far-out fellow star gazer, Marlene Hidalgo, will be joining us to talk about the false dawn of Omar Khayyam.

JAMES: Almost a thousand years ago, the persian poet Omar Khayyam in his book of poetry "The Rubaiyat" wrote his most famous line "A jug of wine, a loaf of bread and thou beside me singing in the wilderness." but elsewhere in "The Rubaiyat" Omar made a poetic allusion to a mysterious "false dawn" as opposed to the real dawn, which can only be seen at a certain time of year.

DEAN: And this year the next two weeks of this September are your best chances to see it for 2012 because there will be no bright moonlight to overpower this delicate astronomical phenomenon. Let’s take a trip out into space and see what we’re talking about.


MARLENE: O.K. if we could go way out into space and look down on our solar system with super human vision we would notice a faint, almost imperceptible vast cloud extending outward from the sun in the plane of the orbits of Mercury, Venus, Earth and slightly beyond, an enormous cloud of cosmic dust.

JAMES: And while one would expect it would be impossible to see this super faint cloud from Earth, nevertheless in September, when the plane of our earth's orbit is almost vertical to the horizon, we can under the right conditions.

DEAN: And those conditions require that there is no moonlight out and that you must be far away from city lights because even the faintest moonlight or urban lighting will wipe out the extremely delicate, ethereal glow of the false dawn. As a general rule if you can see the Milky Way from where you're observing you'll have a good chance to see this it.


JAMES: To find it look toward the east about 2 hours before sunrise, before the real dawn. It will look like a wedge or cone-shaped dim patch of light about the same brightness as the Milky Way. And it will extend from the horizon about one third to half way up to the zenith, a ghostly, faintly glowing, rounded pyramid of light.

DEAN: This year Venus and Jupiter may help you locate this elusive phenomenon. Venus will be right in the middle of it and Jupiter will give you a marker to show where the upper boundary may lie. Notice that the Milky Way is at an angle to this faint band of light and the Milky Way will be there all night long while ‘the false dawn’ will only appear as dawn approaches. That is about two hours before sunrise.

MARLENE: Now the scientific name of this phenomenon is the Zodiacal Light, and it's caused by sunlight scattering from all those trillions and trillions of dust particles which make up the great cosmic cloud lying in the plane of the planets close to the sun.

DEAN: And while you’re out there looking for the false dawn look over to the right and notice the early morning return of the stars of winter: Orion the Hunter, the brilliant star Sirius in Canis Major and the twins of Gemini, Castor and Pollux which will give you a good idea of where the top of this cone of light should be.

MARLENE: And if you look a bit farther to the left you’ll be able to see the Big Dipper rising in the northeastern sky.

JAMES: And although Omar didn't mention it, this 'false dawn' also has an evening counterpart the 'false dusk', the evening Zodiacal Light, which looks pretty much the same except that it is visible 2 hours after sunset in the west in March when the plane of our earth's orbit is also almost vertical to the horizon.

DEAN: Additionally, if you ever see a similar oval shaped glow directly overhead at midnight you would be seeing the Zodiacal Light's sister phenomenon called the Gegenschein or Counterglow. And Iwonder whether any poet ever wrote about that.

MARLENE: At any rate, remember that September is the month to see the 'false dawn' of Omar Khayyam, the morning Zodiacal Light, which i admit is very elusive.

DEAN: But once you've found it i think you'll know why it appeared in poetry centuries before it appeared in scientific writings

JAMES: So get outside before dawn the next two weeks of this month, be sure you're far from city lights and see if you are as inspired as an ancient poet. Keep looking up!


Episode #12-37 "The False Dawn of Omar Khayyam"
Air Dates September 10 - September 16, 2012

MARLENE: Hey there Star Gazers. Almost a thousand years ago the Persian poet Omar Khayyam wrote about a 'false dawn' which can only be seen in the fall.

DEAN: And which you can see the next two weeks if you're far from city lights because there will be no moon out to hide its faint glow.


MARLENE: Look east about 2 hours before sunrise for a very dim cone shaped patch of light about the brightness of the Milky Way extending from the horizon almost half way up to the zenith. Venus will be in the middle of it and Jupiter will let you know to stop looking for it.

DEAN: Although Omar couldn't know it his 'false dawn' is actually a humongous cloud of cosmic dust extending from the sun past Mercury and Venus and slightly beyond Earth. Astronomers call it the Zodiacal Light.

MARLENE:  And the next two weeks give you your best chance to see it this year. So see what inspired an ancient poet and you may be inspired yourself. Keep looking up!


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