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Monday, January 31, 2011

Astronomy Israel is the Official Provider of Star Tours for Taglit-Birthright Israel

We have been privileged to give star tours to groups from Taglit-Birthright Israel during January. Birthright Israel is a wonderful program that provides scholarships to students who have never visited Israel to come and see the Promised Land. The program also mixes in Israeli students and IDF soldiers (with only a few exceptions, all Israelis must do military duty after completing high school) with a seasoned tour guide. We usually start with groups of around 50, dwindling down to the hard-core interested after a couple of hours. Interestingly enough, it has usually been the women who become fascinated and stick around past the very end. We have had very interesting discussions with them ranging all the way from science to personal counseling about the direction of their lives.

There are too many students to get to Mitzpe Ramon, so we usually meet up with them when they are staying at Sde Boker, only about 10 miles from Mitzpe Ramon. Last week, we rendezvoused with the group at Hawarim Farm, a Bedouin-experience camp not far from Sde Boker. It is in the middle of the desert, but for some reason the camp feels it needs to blast its white and green spotlights across the desert vastness all night long. We had a hard time finding a nearby spot where we could watch the stars, although we were in the middle of the wilderness. Turn off the lights, already!

A hard-core group from Taglit-Birthright Israel stays to the very end of our star tour.

We are scheduled to do another star tour with a group this coming Monday, if the weather holds. We've been getting a few days of steady rain now that we are well into winter. 

Here's hoping we get to meet up, and...

Keep on looking up!

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A Night with Yeshiva Yishrei Lev of Jerusalem

I am always amazed at how many yeshivas there are in Israel, the quality of their rabbis, and of the students. Last Thursday night we took up the students from yeshiva Yishrei Lev in Jerusalem who had come to Mitzpe Ramon to do a day tour of the Machtesh (crater) and finish with a night tour of the stars. They numbered 7 all together, including Rabbi Gordon. They were a great group.

Yeshiva Yishrei Lev, Rabbi Gordon, and me!

Thanks for touring the stars with us and remember, 
Keep on looking up!

Thursday, January 27, 2011

Is the Earth Destined to Have Two Suns?

In one of those displays of National Enquirerdom that seems to strike all too often on the Internet, the Huffington Post wrote an article that received alot of play about the star Betelgeuse going supernova and becoming a second sun in our day time sky. After I explained the bad science behind this "popularization" to an Astronomy Israel tour group from Birthright Israel, one of the students rightly concluded, "So you will have to pick up your children from daycare tomorrow."

Betelgeuse is my favorite star in my favorite constellation, Orion. It is (sometimes) the brightest star in the constellation (it is a variable brightness star), the eighth brightest star in the sky, and one of the most massive and largest stars known. It is one of the few stars whose nature is revealed to the naked eye since it is obviously red. Well, it is "obviously" red only after I point out to our guests that stars actually have naked-eye color and I ask them what color they think Betelgeuse is. Everyone is astonished to realize that Betelgeuse is red, although the women seem to see this more quickly than the men. I then like to do a color comparison with Rigel, the young, hot, white-blue star in Orion's knee.

Betelgeuse and Rigel, the two brightest stars in the constellation Orion. Betelgeuse is an aging red supergiant. Rigel is a bright, young, hot blue-white star. Their natures are revealed even to the naked eye. (Click for full size)

Betelgeuse is what astronomers know as a red supergiant star, a massive star that is nearing the end of its life, has burnt most of its hydrogen and helium fuel in thermonuclear reactions that power it and has cooled, thereby glowing red, a condition visible to the naked eye. A star in this condition is ready to go supernova, that is blow itself to bits in one of the most massive explosions in the universe. A supernova can generate more energy and become brighter than the whole galaxy of stars that contain it, such is the power of a supernova explosion. This, apparently, was the excitement behind the Huffington Post article.

Of course, this has been know for years to astronomers, plus when we realize that "nearing the end of its life" in cosmological terms means "could happen in the next million years", there is no reason to think you will not have to pick your children up from daycare tomorrow. Indeed, even if Betelgeuse were to go supernova tomorrow (or 600 years ago, which it would have to do to go supernova tomorrow, since it is 600 light years distant) it is so far away, that it would be no brighter than the full moon in our daytime sky, and still just a point of light to our naked eye. Bright, yes, but not exactly a second sun. This could last for anywhere from a few days to a few months as the dying star collapsed to a neutron star core.

Betelgeuse, as imaged by the Hubble Telescope in 1995, would extend beyond the orbit of Jupiter if in place of our sun, consuming 75% of our solar system.

One of the more amazing things about Betelgeuse is that it is so huge that it was the first star whose stellar disk was resolved by telescopes on earth, the first such stellar disk besides our sun's ever seen. This was done using a technique called speckle interferometry in which the output of two telescopes separated by some distance is combined to create a single image of a star. In 1995 the Hubble Space Telescope was the first single telescope to reveal the disk of the star. Recently, using the Infrared Optical Telescope Array (IOTA), the disk of Betelgeuse was resolved using interferometry to reveal two hot spots.

Two hot spots are imaged on the star Betelgeuse by the IOTA.

Betelgeuse is so large that if it were in the place of our sun, its radius would extend to engulf the planet Jupiter, or much of our entire solar system.

But you're still going to have to pick up your kids from day care tomorrow. And probably for at least a few 100,000 years beyond that. Maybe even a million.

Keep on looking up!

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Wednesday, January 26, 2011

Tangerine Moon

Last Monday, January 24th, we were returning from Hawarim Farm where we did another fun astro tour for Taglit/Birthright Israel. As we turned onto the perimeter road that skirts the edge of Machtesh Ramon we came upon a huge last quarter moon rising over the desert, peering into the abyss of the giant crater. It looked like nothing so much as a gigantic, juicy slice of fresh tangerine. Here it is for your delectation and delight.

A tangerine moon rises over Machtesh Ramon (Click for full size image)

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Tuesday, January 18, 2011

Full Moons of the New Year

Original caption from NASA: "S103-E-5037 ...Image via WikipediaThis post is based on Joe Rao's article (See below), which is well worth your time to read in full. Full moons have many names in different cultures. Some of the most poetic and evocative come from Native American names, based on agriculture and hunting. It can be difficult to find them all in one place, so thanks to Joe Rao for giving us this summary and article.


If you know of any others from different cultures please let us know in the Comments or via email and we will update them here.

Jan. 19, 11:21 p.m. IST – Full Wolf Moon/Old Moon/Moon after Yule. The wolves begin to howl.

Feb. 18, 10:36 a.m. IST – Full Snow Moon/Full Hunger Moon. Summer's grain is all gone.

Mar. 19, 9:10 p.m. IST – Full Worm Moon/Full Crow Moon/Full Sap Moon. Sap's a risin'.

The moon will also arrive at perigee only 50 minutes later at 11:00 p.m. IST at a distance of 221,565 miles (356,575 kilometers) from Earth. So this is the biggest full moon of 2011. Very high ocean tides can be expected during the next two or three days, thanks to the coincidence of perigee with full moon.

Apr. 18, 5:44 p.m. IDT – Paschal Full Moon/Full Pink Moon/Full Fish Moon/Egg Moon/Full Sprouting Grass Moon

In 2011, this is also the Paschal Full Moon; the first full moon of the spring season. The first Sunday following the Paschal Moon is Easter Sunday, which indeed will be observed one week later on Sunday, April 24. This, incidentally, is just one day shy of the latest date that Easter can fall. Not by coincidence, April 18th is also the first Seder night of Pesach/Passover. This is a leap year in the Jewish calendar with an extra month (Adar II) added. This is why Pesach, and with it Easter, are so late this year.

May 17, 2:09 p.m. IDT – Full Flower Moon/Full Corn Planting Moon/Milk Moon

Jun. 15, 11:14 p.m. IDT – Full Strawberry Moon/Rose Moon. "Pick ye strawberries while ye may..."

Jul. 15, 9:40 a.m. IDT – Full Buck Moon/Full Buck Moon/Full Hay Moon. Hunting season for Native Americans.

Aug. 13, 9:57 p.m. IDT – Full Sturgeon Moon/Full Red Moon/Green Corn Moon/Grain Moon. Summer haze turns the moon red near the horizon. Fish run upstream. Corn begins to ripen.

The occurrence of this full moon on this particular date is rather poor timing for those who enjoy the annual performance of the Perseid meteor shower; this display will peak on this very same day and the brilliant light of the moon will likely wash out all but the very brightest of these swift streaks of light.

Sep. 13, 12:27 a.m. IDT – Full Harvest Moon: Traditionally, this designation goes to the full moon that occurs closest to the autumnal (fall) equinox (September 21). The Harvest Moon usually comes in September in the Northern Hemisphere, but (on average) once or twice a decade it will fall in early October.

At the peak of the harvest, farmers can work into the night by the light of this moon. Usually the moon rises an average of 50 minutes later each night, but for the few nights around the Harvest Moon, the moon seems to rise at nearly the same time each night – just 25 to 30 minutes later across the U.S., and only 10 to 20 minutes later for much of Canada and Europe. Corn, pumpkins, squash, beans and wild rice – the chief Indian staples – are now ready for gathering. If you come out with us on or near a full-moon night you will be amazed at how bright it is. That's why the Indians never attacked the fort during full moon.

Oct. 12, 4:06 p.m. IST – Full Hunters' Moon. Fall hunting season.

Since the moon arrives at apogee about 10 hours later, this will also be the smallest full moon of 2011. In terms of apparent size, it will appear 12.3 percent smaller than the full moon of Mar.19.

Nov. 10, 10:16 p.m. IST – Full Beaver Moon/Frosty Moon. Winter is a cumin' in.

Dec. 10, 4:36 p.m. IST – Full Cold Moon/Moon Before Yule/Full Long Nights Moon

Sometimes this moon is referred to as the Full Long Nights Moon, and the term "Long Night" Moon is a very appropriate name because the nights are now indeed long and the moon is above the horizon a long time. This particular full moon makes its highest arc across the sky because it's diametrically opposite to the low sun.



Keep on looking up!

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Sunday, January 16, 2011

Clouded Out

Two braided Shabbat challahs placed under an e...Image via WikipediaWe were planning to go up this Saturday evening with a small group from Chez Eugene, but the clouds cancelled us out. This Shabbat has been cold, windy and rainy. The rain stopped, but clouds, wind and cold continued through the night. Perhaps we shall have better luck in the new week.

Keep on looking up!



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A Four Star Night

We had the pleasure of hosting Katherine and Evan last Wednesday night under a first quarter moon. Jupiter and Uranus were still visible in the same wide-angle telescopic field and continue to make an impressive sight. People are just amazed to find out that while visible near each other in a line from earth, Uranus is 1.4 billion miles farther away than Jupiter.

The moon, although bright, did not interfere too much with our observations and made a splendid spectacle itself in the telescope. We had a good view of the Lunar Alps and Piton in Mare Imbrium.

We tried to split the Pup again (drum roll), but failed (raspberry). This is still at the top of our observing list this season. Who will be the lucky guests to be counted among the few on earth who have split the Pup? Only time will tell.

Evan was a fast learner and got three stars for being able to answer all of my questions on night vision and the position of the North Star from various latitudes on Earth. Katherine got a gold star for quickly identifying star colors, especially the Red Giants Betelgeuse and Aldebaran. She also called Capella's yellow tint immediately. A four star night! (Note to self: must get gold stars to paste on people's astronomy portfolios.)

Evan is a medical student at Ben Gurion University of the Negev and Katherine is a writer for Time Out Israel. Maybe she will write something nice about us. Could we have a picture, too? :-)

Evan and Katherine, our cute young couple from Beer-Sheva

Keep on looking up!


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Thursday, January 13, 2011

Holy Mackerel!

A Mackerel Sky nearly ruined our night under the stars with Ilana and Yossi, but we persevered until the clouds dissipated. In addition to clouds we had to contend with a first quarter moon, which is really bright under the dark skies of the desert.

We had a marvelous view of Jupiter as it set in the west, right next to the moon-illuminated dome of the Wise Observatory. I didn't get a chance to take a picture through the telescope, so you'll just have to take my word how cool it is to see Jupiter and its 4 Galilean moons sink below the horizon in the same field of view as the great dome of the observatory. Not far away (visually) was Uranus, although 1.4 billion miles separated it from Jupiter.

The Great Nebula in Orion shone brightly, defying the light of the first quarter moon. We tried to split the Pup again, but did not achieve our goal, despite using a power of 300x. This remains on our list of "must do" items this winter observing season.

Splitting the Pup: Sirius has a dim 8th magnitude companion just 11 arc seconds distant during 2011. It is affectionately known as the Pup, since Sirius has been known as the Dog Star for millennia.

We hope to see Ilana and Yossi again with their extended family for a family tour of the night sky from Mitzpe Ramon.

Yossi, Ilana and me after our observing session.

Keep on looking up!
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Sunset, January 12, 2011

Mackerel sky over Lincolnshire, England.Image via WikipediaHigh, thin cirrus clouds dominate the desert this time of year. The wind sometimes blows them into Mares' Tails. At night they can create what's called a Mackerel Sky, where the clouds cover the sky like scales on a fish. They are made of ice crystals. At sunset they create very beautiful effects, like this sunset today.

A winter sunset in Mitzpe Ramon with our signature water tower.

Keep on looking up!

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Monday, January 10, 2011

New Year's Observing with Guests from the Arctic Circle

No, it wasn't Rudolf the Red Nose Reindeer. It was Partow Izadi and his family from Finland. Partow is an experienced amateur astronomer and was looking forward to a night under the stars without the freezing temperatures of his home in Finland near the arctic circle. We still couldn't resist teasing him about getting cold at 30 degrees north latitude, but he really didn't come dressed for freezing desert temps.

I was surprised when he told me how many dedicated amateur astronomers there are in Finland, where arctic temperatures, a nearly unchanging sky in the winter, and the midnight sun in the summer make observing a real challenge. Apparently there are many astronomy clubs in the country with avid members. At least he gets good views of the Aurora Borealis!

Thanks for being our guests and come back to visit Israel soon, Partow!

The Izadi family, from Finland, and me. (Click for full size image.)

Keep on looking up!


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Sunday, January 9, 2011

The Partial Solar Eclipse of January 4, 2011 from Israel

GIVATAYIM, ISRAEL - JANUARY 04:   The view of ...Image by Getty Images via @daylifeLast Tuesday's partial solar eclipse was well seen from Mitzpe Ramon, but much of northern Israel was under cloud cover and so missed the event. I set up in from the of the CafeNeto to allow the public to get a view using an 80mm refractor with a white light sun filter, naked eye with a #14 welder's glass, and naked eye through clouds that moved in toward the end.

The best metaphor for the eclipse came from my friend Shiki, who took a look through the telescope and said "Banana". I had never heard that one before. A Bedouin looked through the telescope and exclaimed, "Allah Akhbar" (Allah is great.) A number of high school students from the yeshiva came by and were the most excited of all. They really liked the naked eye view through the #14 welder's glass. I must admit there is something very compelling about seeing an eclipse of the sun directly with your naked eye. It has an immediacy lacking in the telescopic view.

Solar eclipse through my 80mm refractor with white light solar filter. (Photo: Ira Machefsky; click for full size image.)

Naked eye view of eclipse through clouds from Mitzpe Ramon. (Photo: Ira Machefsky; click for full size.)


There will not be another partial solar eclipse visible from Israel until March 2015. The last one visible from here was in August 1999.

Keep on looking up!
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Monday, January 3, 2011

How to See Tonight's Quadrantids Meteor Shower from Israel (or Anywhere Else for that Matter)

The Quadrantids meteor shower peaks early this Tuesday morning, January 4, 2011. Go out after midnight. Find as dark a location as you can. Face eastward, looking as high in the sky as you comfortably can. Lie down on your back in a sleeping bag or find a comfortable chair. Watch and enjoy. The peak is very brief and unpredictable, so stay out as long as you can. Defy the cold!!! No optical aid needed at all.


And don't forget that if you live in Europe, Africa, Asia or the Middle East, an excellent partial eclipse of the sun begins at around 9:00AM Israel Standard Time Tuesday morning, January 4, 2011.

Good luck.

Keep on looking up!



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Sunday, January 2, 2011

Starting the New Year with a Solar Eclipse in Israel

More good news for sky watchers. Start off the New Year with a partial solar eclipse that is well seen from Israel on Tuesday, January 4, 2011. This is not a total eclipse anywhere, but sky watchers in Europe, Africa, the Middle East and Asia will be able to see it well. The greatest extent of coverage will be in Stockholm, Sweden, where 79% of the sun will be covered at 9:42am local time.

In Israel the eclipse will begin at 9:09am, with maximum coverage of 47% reached at 10:41am local time. If you are without clouds, look carefully and you may be able to see a "dulling" of the sunshine around mid-eclipse, but the sun is so bright that only a total eclipse darkens the sky. Sometimes a perceptible drop in temperature can be felt around mid-eclipse as well.

I must caution you not to look directly at the sun with the naked eye, even during a partial eclipse, and certainly never with any optical instrument, unless it has been designated for solar use. More than a glance at the sun can cause permanent damage to eyesight. This includes smoked glass, exposed negatives or any other home made item, however dark. Also, sunglasses, however dark, are not safe for solar viewing. They can still allow harmful rays to reach the eye. Welders #14 glass can be used to view the eclipse with the naked eye or this projection system that you can make at home. You will be tempted to keep trying to watch the sun with your naked eye. Don't do that. Children's eyes are particularly susceptible to injury. There are special astronomical sun filters and films that can be used. You may find them for sale in various places, including camera shops.

                     Start          Middle         End       Sun Coverage
Tel Aviv    9:09am      10:41am    12:16pm         47%

Visibility of Partial Solar Eclipse, Tuesday, January 4, 2011

This eclipse allows us to directly view the "molad", the birth of the new moon of Shevat, but Rosh Chodesh, the first of the new month, will not occur until Thursday. This is because ordinarily the new moon of a month would not be visible until 12-24 hours after its astronomical occurrence, which is the earliest witnesses could report it to the Bet Din. Rosh Chodesh in the Jewish calendar is an observable event, not one calculated by celestial mechanics.

Barekat Observatory in Israel will webcast the event for those not able to get outside.

Chodesh Tov.

Keep on looking up.

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A Red Letter Observing Night

A Trouvelot lithograph depicting zodiacal lightZodiacal Light via WikipediaLast Tuesday night we had the Tellers and the Zamchecks under the stars and enjoyed some unique observing experiences. As I was showing them the Milky Way one of them (it was Michael Teller who deserves full credit for this observation) pointed to the horizon and asked, "What's that?" "That", as it turns out was the Zodiacal Light, a phenomenon I had never seen before.

I remembered talking to one of the astronomy graduate students at the Wise Observatory in November, and he remarked that he had seen the Zodiacal Light for the first time from Mitzpe Ramon that month. The Zodiacal Light is a fan of light that rises from the horizon toward the sky following the path of the Zodiac, or ecliptic, and is caused by the reflection of sunlight from dust and debris in the plane of the solar system. It takes a very dark, clear sky and unobstructed horizon to see it, together with circumstances of the position of the sun and ecliptic that I won't go into here. It was awe inspiring to see the band of the winter Milky Way, our galaxy, overhead with the band of the Zodiacal Light, our solar system next to it, and us standing on earth in between, our place in the cosmos clearly seen.

This alone would have sufficed to make for a red letter night. But wait - it gets better. Jupiter is a favorite telescope object right now, high overhead on an early winter's night. For the third time this year Jupiter appears quite close to Uranus as seen from the earth, just 1/2 a degree or the width of the full moon distant, and visible in the same low power telescopic field. (Although the positions of the two planets appear close in the sky as viewed from the earth, this is just an optical alignment. In reality the two planets are 15.21 astronomical units apart, or 1,414,530,000 miles. Yes, over 1.4 billion miles.) It was a wonderment to see the dark-striped disk of creamy Jupiter with three of its Galilean moons alongside, while just above it and to the side rode aquamarine Uranus like a small bubble in the black sky. I will never forget this beautiful sight, and almost refused to surrender my place at the telescope to our guests.

This photo, taken in September during an earlier conjunction, is a good approximation of the view in our telescope of Jupiter, its Galilean moons and Uranus on Tuesday night. Our colors were more intense. (Photo credit: Jin Lu) Click for full size image.

The sights made everyone giddy with excitement, so when I mentioned that Saturn would be rising about 12:30 AM, we decided to reconvene the group then and go up for another look. This was also my first view of Saturn for this season. It did not disappoint. Not only were the rings magnificent but we could also see Titan, Saturn's largest moon, and possibly a few other smaller ones.

As the last quarter moon rose in the sky with Saturn, the moon beams stuck us and for a moment we became "lunatiks". The group broke into a spontaneous snake dance across the hard rocks of the desert. 


A little night music 

Exhausted but well satisfied with our night's observing, we returned home.

Tellers, Zamchecks and that wiley old moon.

Keep on looking up!
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