Elementary Astronomy News Highlights
Each week in 107-02 we will discuss something interesting that has been in the news. The subjects will be drawn from the New York Times, [http://apod.nasa.gov/apod/ Astronomy Picture of the Day], and press releases from NASA, the European Space Agency, the European Southern Observatory, or the Space Telescope Institute. If there is something interesting from one of our telescopes we may tell you about that too. This page has the highlights.
Week of February 27, 2012
Astronomers using a telescope in Chile discovered "light echos" of eruptions in the double star system Eta Carinae. The events were seen from Earth in the 1800's, when the star brightened to be the second brightest star in the sky. It is now a faint 8th magnitude. Some light from the eruption scatters off of dust around the star and then reaches us later than the light that comes directly toward us. The scattered "light echo" was analyzed to determine the explosion was unexpectedly cooler than we had predicted. The fate of stars like Eta Carinae is to become a supernova, sending their matter back into space, and seeding the formation of another generation of stars.
You can read about the discovery on National Geographics website.
Week of February 20, 2012
Mars will be in opposition on March 3 this year. It is now rising just a few minutes after sunset, and is visible most of the night. This is how it looked in a small 7-inch diameter telescope at our observatory on Monday morning, February 20.
New Moon is on Tuesday this week, and during the week it will grow from a thin crescent on the western horizon at sunset to first quarter Moon, high in the sky at sunset next Tuesday.
Week of February 13, 2012
While really news from last week, it's too good to let this one pass. A large meteorite that fell on Morocco on July 18, 2011, originated on Mars. Ejected by a collision of Mars with another space rock, this one went on a trajectory that eventually ended in the Moroccan desert near Tissint. It was acquired for the Natural History Museum in London, and is the largest martian meteorite in their collection. There is a nice video about it available on their website:
On its way from Mars to the desert and then to the Museum, it made a trip by airplane to New York, took a bicycle ride around Manhattan, and then went as carry-on luggage to Great Britain. The story is in the New York Times for February 9, 2011.
Week of February 6, 2012
The Astronomy Picture of the Day (APOD) for February 4, 2012, featured Comet Garradd, known officially as C2009/P1, as it appeared in the morning sky in the constellation Hercules on February 3.
From the APOD description --
The (yellow) dust tail tends to trail the comet along its orbit while the (blue) ion tail, blown by the solar wind, streams away from the comet in the direction opposite the Sun. Of course, M92 is over 25,000 light-years away. Comet Garradd is 12.5 light-minutes from planet Earth, arcing above the ecliptic plane.
You may be able to find the comet with binoculars in a dark morning sky this month. Sky and Telescope provides a map and observing suggestions here:
Week of January 30, 2012
The New York Times reported that a project to search for extraterrestrial intelligence (SETI) has found funding to continue its work, at least for a few months. You can read the full article in the New YorkTimes on line.
Highlights from the New York Times article --
"Advanced life and technology might be rare in the cosmos, said Geoffrey W. Marcy, the Watson and Marilyn Alberts in the Search for Extraterrestrial Intelligence professor at the University of California, Berkeley, “but surely they are out there, because the number of Earthlike planets in the Milky Way galaxy is simply too great.”
A simple “howdy,” a squeal or squawk, or an incomprehensible stream of numbers captured by one of the antennas here at the University of California’s Hat Creek Radio Observatory would be enough to end our cosmic loneliness and change history, not to mention science. It would answer one of the most profound questions humans ask: Are we alone in the universe?
Despite decades of space probes and billions of NASA dollars looking for life out there, there is still only one example of life in the universe: the DNA-based web of biology on Earth. “In this field,” said Jill Tarter, an astronomer at the SETI Institute in Mountain View, Calif., the “number two is the all-important number. We count one, two, infinity. We’re all looking for number two.”
Week of January 23, 2012
The week opened with a report of giant solar flare with the prompt emission of X-rays and the ejection of charged particles on a path toward Earth. It produced an aurora that was visible in northern latitudes and reported in Astronomy Picture of the Day for January 24. Another event occurred the following day, with the possibility of another aurora and disruption of communications on Tuesday.
These observatories continously monitor the Sun from space and provide real-time images and data about Space Weather:
The colors of the aurora borealis, or northern lights, appear above the city of Tromsoe, in northern Norway. Stargazers were out in force across northern Europe on Tuesday night, hoping to be awed by a spectacular show fueled by the most powerful solar storm in six years. The bright auroras are also visible across Alaska and Canada. Credit: Washington Post, January 26, 2012
Week of January 16, 2012
The New York Times and Nature reported the discovery of more planets orbiting two stars. Like the fictional Tatooine of Star Wars there would be two "suns" in the sky if you could stand on them and look up. However, these new discoveries are the size of Saturn, and they are so close to their stars that they are too hot to be habitable.
The first planet found orbiting two stars was Kepler 16b. The Kepler telescope finds planets by capturing the moment when they pass between us and their stars, blocking out a tiny fraction of the star's light (often less than 0.1%). These events allow astronomers to measure the size of the orbit, the diameter of the planet, and in some instances even the planet's atmosphere. For Kepler 16 the data look like this:
A planet like Earth is at just right distance -- in the Goldilocks zone -- where life such as we know it can flourish. Other known planets are usually either too close to their star(s) and too hot, are too far away and too cold.
Week of January 9, 2012
The science journal Nature reported the discovery made at the Very Large Telescope of the European Southern Observatory of a cloud of gas that is on a trajectory to fall into the million-solar-mass black hole at the center of the Milky Way. Click this link to see what they had to say.You may have to be connected through the University of Louisville's network to read the full article.
A gas cloud has been spotted approaching the Milky Way's central black hole. Observations of its closest approach, expected to occur in mid-2013, may offer insight into the black hole's immediate surroundings.
The discovery was also described in the New York Times with the headline Black Hole Forecast: A Cold Gas Cloud
The center of the Milky Way is a site known as Sagittarius A*, or SgrA* for short. You can watch a short video about this here: