Nice to wake up to the sun shine this morning. The haze of the past week was swept away so completely that the waning crescent moon stood out sharply in the clean sky even at 9 o’clock. The Clear Sky Chart for our region forecasts cloudless skies through the early hours of tomorrow morning. This will give us a great chance to see lots of satellites (see yesterday’s blog) and find the Dumbbell Nebula. More about that in a minute.
On Monday, an unidentified man adjusts a telescope that once belonged to Albert Einstein. Students and visitors will be able to look through the long-lost scope starting Thursday after it’s renovated. (AP Photo/Hebrew University in Jerusalem)
I read in today’s paper about the discovery of Einstein’s long-lost telescope. It was stored in a shed at Hebrew University in Jerusalem. Einstein received the scope in 1954, the year before he died, as a gift from his friend Zvi Gizeri. Gizeri likely made the scope himself. It’s clearly a reflecting telescope — one that uses mirrors to gather and focus light — on a heavy-duty metal mount. Since the tube measures about eight inches in diameter and six feet long, the mirror would be six to eight inches across. This would have been a substantial amateur telescope for the era.
You wonder if Einstein actually used it to look at the sky. If he toted the scope into his front yard on September 24, 1954, he would have seen Mars almost exactly where Jupiter is now in Sagittarius. More likely, he pondered equations deep into the night, trying to reconcile quantum mechanics with relativity. Let’s assume he stepped out into the pre-dawn air to clear his head. If Einstein looked to the east, Jupiter in Gemini would have caught his gaze for sure. We’ll probably never know for certain if he hauled it outside for a look-see, but it’s cool just to know that Einstein had a telescope.
This map shows the southern sky around 9 o’clock this week. You’ll recall that Vega, Deneb and Altair form the familiar asterism of the Summer Triangle. Altair is due south and halfway up in the sky. The Dumbbell’s home is the faint constellation of Vulpecula the Fox. To find the nebula, you can use Sagitta the Arrow, located one outstretched fist above Altair. — created with Stellarium
You won’t need a telescope to see the Dumbbell Nebula, which is located just above the little, arrow-shaped constellation of Sagitta the Arrow this fall. Binoculars will do. The Dumbbell was the first planetary nebula to be discovered. It was snagged in telescopic sweeps by that famous seeker of comets, Charles Messier, in 1764. Planetary nebulas are small, round clouds of glowing gas whose distinct shapes reminded early astronomers of planets, hence the name.
At the center of each planetary is a faint, tiny and impossibly dense star called a white dwarf. One teaspoon of white dwarf matter weighs five tons. Or how about this: A white dwarf packs an entire sun’s worth of matter into a sphere the size of Earth. They’re the ultimate tin of sardines.
The Dumbbell Nebula, also known as M27 (the 27th entry in Messier’s catalog of deep sky objects) shines by the light of the white dwarf star visible at its center. The Dumbbell is around 1300 light years from Earth. This time-exposure photo reveals the green glow of excited oxygen atoms in rarified gas. Photo: Jim Misti
The sun will evolve into a white dwarf as it ages and ultimately runs out of nuclear fuel. Some four to five billion years from now, our favorite star will shed its atmosphere, exposing its very core. The intense ultraviolet radiation from the core, now called a white dwarf star, will excite the expanding shell of its former atmosphere and create a beautiful, glowing sphere. Voila! A planetary nebula. Their lovely oval and round shapes and cool blue-green colors place planetaries high on the "favorites" list of amateur astronomers.
The Dumbbell gets its name from the familiar hand weight form, which shows very nicely in a telescope. The nebula is also easily seen in ordinary binoculars as a fuzzy, cloud-like patch some three "fingers" above the end of the Sagitta arrow. Point your binoculars right above Altair, and find the line of stars that make the arrow. The nebula is directly above the arrow tip. Matter of fact, if you put the "tip star" in the bottom of your binocular field, you’ll probably see the Dumbbell in the top half.
Binocular star gazing is more challenging than naked eye but when mastered, you’ll be on a first-name basis with more members of the cosmic zoo than you ever realized were there.