Variable Stars

With a Motive for expanding our knowledge of Astronomy, the club decided to get together every Thursday for discussions on the recent events in the area. The first one of such Thursdays saw a discussion on variable stars. Basically, Variables are those objects in the night sky whose apparent brightness (i.e. as seen from earth) changes over time. The changes may be due to a variation in the star’s actual luminosity, intrinsic variables or due to variations in the amount of the star's light that is blocked from reaching Earth, Extrinsic variables.

Our very own pole star or Polaris belongs to the class of Variable Stars, accurately, it is part of the Cepheid variables, a class of pulsating stars that swell and shrink extremely regularly. Generally in each subgroup of the class, a fixed relation holds between period and absolute magnitude, as well as a relation between period and mean density of the star hence enabling astronomers to gauge the distances of such stars from the earth.

Like a Diamond in the Sky

...Like a Diamond in the Sky"





I remember looking up at the sky when I was a kid and had no idea what the thousands of dots in the sky were. They looked like tiny pin pricks which showed bits of some holy daylight from beyond the otherwise dark night sky. And that was probably the beginning of a four-year old’s fascination for the night sky; the thousands of bright pinpricks –the twinkling little stars. For all of you out there, who feel or have felt even the tiniest of inklings of awe and wonder for the vast dark night sky at some point of time; I’m sure you have your own story to tell.

Throughout man’s existence on the planet, since the time of the early Neanderthal man, he has tried to explain what the sky, the pinpricks meant; what they implied. We had our share of men –astronomers and physicists who strived to solve the mysterious unexplained, right above them in the sky.

“Where does it come from? This quest, this need to solve life's mysteries, of the simplest of questions can never be answered. Perhaps we'd be better not looking at all, not delving, and not yearning. But that's not human nature, not the human heart. That is not why we are here.”

We will keep looking. We will keep searching for answers. We will always be awed by themahakaash. We will keep looking at the constellations, the stars, the planets, the nebulae, the thousands of pinpricks and wonder. And be amazed now, tomorrow, for many many years to come.

***

Men came and went. Theories came and went. Models of the Universe explaining why the night sky is the way it is, were given. Few of them accepted. Even they went. The only thing that stayed the way it was, was the sky and man’s fascination for the unexplained.

For the thousands of bright pinpricks in the sky...

Transit of Venus, 2012

The next transit of Venus will occur on June 5–June 6 in 2012, succeeding the previous transit on June 8, 2004. After 2012, the next transits of Venus will be in December 2117 and December 2125.

A computer simulation of the transit as seen from Beijing,China



Where visible

Where the 2012 transit will be visible

The transit will be best viewed from the Pacific Ocean. North America will be able to see the start of the transit, while South Asia, the Middle East, and most of Europe will catch the end of it. The transit will not be visible in most of South America or western Africa. The regions from which the transit is visible are shown in the map to the right.

When visible

Total Lunar Eclipse -- 12 December

These are the Photos we Clicked at India Gate, New Delhi , India on 10 December Lunar Eclipse.

Strange New 'Species' of Ultra-Red Galaxy Discovered

"We've had to go to extremes to get the models to match our observations," said Jiasheng Huang of the Harvard-Smithsonian Center for Astrophysics (CfA). Huang is lead author on the paper announcing the find, which was published online by the Astrophysical Journal.

Spitzer succeeded where Hubble failed because Spitzer is sensitive to infrared light -- light so red that it lies beyond the visible part of the spectrum. The newfound galaxies are more than 60 times brighter in the infrared than they are at the reddest colors Hubble can detect.

Galaxies can be very red for several reasons. They might be very dusty. They might contain many old, red stars. Or they might be very distant, in which case the expansion of the universe stretches their light to longer wavelengths and hence redder colors (a process known as redshifting). All three reasons seem to apply to the newfound galaxies.

All four galaxies are grouped near each other and appear to be physically associated, rather than being a chance line-up. Due to their great distance, we see them as they were only a billion years after the Big Bang -- an era when the first galaxies formed.

"Hubble has shown us some of the first protogalaxies that formed, but nothing that looks like this. In a sense, these galaxies might be a 'missing link' in galactic evolution" said co-author Giovanni Fazio of the CfA.

Next, researchers hope to measure an accurate redshift for the galaxies, which will require more powerful instruments like the Large Millimeter Telescope or Atacama Large Millimeter Array. They also plan to search for more examples of this new "species" of extremely red galaxies.

"There's evidence for others in other regions of the sky. We'll analyze more Spitzer and Hubble observations to track them down," said Fazio.

NASA's Jet Propulsion Laboratory, Pasadena, Calif., manages the Spitzer mission for NASA's Science Mission Directorate. Science operations are conducted at the Spitzer Science Center at the California Institute of Technology in Pasadena. NASA's Goddard Space Flight Center built Spitzer's Infrared Array Camera, which took the observations. The instrument's principal investigator is Giovanni Fazio of CfA.

Canary Islands Antenna Being Modified to Boost Signal to Struggling Russian Mars Probe

Maspalomas station hosts a 15-metre antenna with reception in S- and X-Band and transmission in S-band. It is located on the campus of the Instituto Nacional de Tecnica Aerospacial (INTA), in the southern part of the Canary Islands' Gran Canaria, at Montaña Blanca.Credit: ESA

As part of an effort to improve communication with the Russian Space Agency’s Phobos-Grunt spacecraft, modifications are being made to a 15-meter dish antenna at Maspalomas station. Located in the Canary Islands off the Atlantic coast of North Africa, the station provides tracking, telemetry, and other functions in support of the European Space Operations Centre (ESOC) of the European Space Agency (ESA).

Last week, ESA succeeded in communicating with Phobos-Grunt on two successive days after a feedhorn antenna was added to an antenna near Perth, Australia similar to the facility in Maspalomas. Although this enabled the downloading of spacecraft telemetry, attempts later in the week to make renewed contact failed. After no attempts were made over the weekend, commands aimed at getting the spacecraft to boost its orbit were sent yesterday, also from Perth, but tracking this morning revealed that the commands had not been executed.

Launched November 9 from the Baikonur Cosmodrome, in Kazakhstan, Grunt is an unpiloted science probe built to travel to Phobos, the larger of Mars’ two small moons. On board is a science payload consisting of numerous instruments designed to elucidate the structure and origin of Phobos, the composition of its surface material, and possibly dust from Mars that may be present as well. A Chinese probe called Yinhuo-1 is to be delivered into orbit around Mars, while the rest of the payload is to land on the Phobosian surface. Some time after landing, a 200 gram sample of the surface is to be deposited into a capsule which then will launch for a journey back to Earth. Also traveling in the return capsule is thePlanetary Society’s Living Interplanetary Flight Experiment (LIFE), which I helped to design. As with the Phobosian surface sample, the LIFE experiment will be valuable scientifically,only if the return capsule can be returned to Earth.

Although Phobos-Grunt was delivered into space nearly three weeks ago by a Zenit 2 rocket launch that appeared flawless, an upper stage rocket known as Fregat failed to ignite. This left the spacecraft in a low Earth orbit that improved as a result of the automated maneuvering, but that will decay by mid-January if the altitude is not boosted more significantly. Because a low orbit requires a spacecraft to move more swiftly with respect to the ground, communication is extremely limited due both to time and geometry. By allowing Maspalomas to operate similarly to Perth, but from its different location, both geometric and time factors affecting communication will be improved. Should this result in the spacecraft executing commands to climb to a higher orbit, further communication and diagnosis of spacecraft systems then would become much easier.

Mars Science Laboratory: NASA Launches Most Capable and Robust Rover to Red Planet

Credit: NASA/Bill White

NASA began a historic voyage to Mars with the Nov. 26 launch of the Mars Science Laboratory, which carries a car-sized rover named Curiosity. Liftoff from Cape Canaveral Air Force Station aboard an Atlas V rocket occurred at 10:02 a.m. EST (7:02 a.m. PST).

"We are very excited about sending the world's most advanced scientific laboratory to Mars," NASA Administrator Charles Bolden said. "MSL will tell us critical things we need to know about Mars, and while it advances science, we'll be working on the capabilities for a human mission to the Red Planet and to other destinations where we've never been."

The mission will pioneer precision landing technology and a sky-crane touchdown to place Curiosity near the foot of a mountain inside Gale Crater on Aug. 6, 2012. During a nearly two-year prime mission after landing, the rover will investigate whether the region has ever offered conditions favorable for microbial life, including the chemical ingredients for life.

"The launch vehicle has given us a great injection into our trajectory, and we're on our way to Mars," said Mars Science Laboratory Project Manager Peter Theisinger of NASA's Jet Propulsion Laboratory in Pasadena, Calif. "The spacecraft is in communication, thermally stable and power positive."

The Atlas V initially lofted the spacecraft into Earth orbit and then, with a second burst from the vehicle's upper stage, pushed it out of Earth orbit into a 352-million-mile (567-million-kilometer) journey to Mars.

"Our first trajectory correction maneuver will be in about two weeks," Theisinger said. "We'll do instrument checkouts in the next several weeks and continue with thorough preparations for the landing on Mars and operations on the surface."

Curiosity's ambitious science goals are among the mission's many differences from earlier Mars rovers. It will use a drill and scoop at the end of its robotic arm to gather soil and powdered samples of rock interiors, then sieve and parcel out these samples into analytical laboratory instruments inside the rover. Curiosity carries 10 science instruments with a total mass 15 times as large as the science-instrument payloads on the Mars rovers Spirit and Opportunity. Some of the tools are the first of their kind on Mars, such as a laser-firing instrument for checking the elemental composition of rocks from a distance, and an X-ray diffraction instrument for definitive identification of minerals in powdered samples.

To haul and wield its science payload, Curiosity is twice as long and five times as heavy as Spirit or Opportunity. Because of its one-ton mass, Curiosity is too heavy to employ airbags to cushion its landing as previous Mars rovers could. Part of the Mars Science Laboratory spacecraft is a rocket-powered descent stage that will lower the rover on tethers as the rocket engines control the speed of descent.

The mission's landing site offers Curiosity access for driving to layers of the mountain inside Gale Crater. Observations from orbit have identified clay and sulfate minerals in the lower layers, indicating a wet history.

Precision landing maneuvers as the spacecraft flies through the Martian atmosphere before opening its parachute make Gale a safe target for the first time. This innovation shrinks the target area to less than one-fourth the size of earlier Mars landing targets. Without it, rough terrain at the edges of Curiosity's target would make the site unacceptably hazardous.

The innovations for landing a heavier spacecraft with greater precision are steps in technology development for human Mars missions. In addition, Curiosity carries an instrument for monitoring the natural radiation environment on Mars, important information for designing human Mars missions that protect astronauts' health.

The mission is managed by JPL, a division of the California Institute of Technology in Pasadena, for NASA's Science Mission Directorate in Washington. The rover was designed, developed and assembled at JPL. NASA's Launch Services Program at the Kennedy Space Center in Florida managed the launch. NASA's Space Network provided space communication services for the launch vehicle. NASA's Deep Space Network will provide spacecraft acquisition and mission communication.

Trip TO MAAAAAAAAAAAAAAAAAAAARRRSSSS!!!!!!!!!!

The mars rover lift off is scheduled for 1502hrs GMT!!!!

Stay tuned for more updates!!

Astro Olympiad

Siase is organizing an Astronomy Olympiad in the first week of december!!!! 

ISS Crew May Be Forced To Take Shelter From Space Debris.

The International Space Station. Credit: NASA

What a fine welcome for the new crew on board the ISS: The three astronauts/cosmonauts on the space station may have to take shelter in their Soyuz spacecraft early Wednesday morning (Nov. 23), due to a close flyby or even a possible collision with a piece of space debris. Mission Control called up to the Expedition 30 at 2:06 pm EST today (Nov. 22), saying it was too late to do a debris avoidance maneuver with the entire station, and the crew should be ready to “shelter in place” in the Soyuz vehicle.

Reports are that the object is a piece of debris about 4 inches (10 centimeters) in diameter from the Chinese Fengyun 1C weather satellite that was destroyed in 2007. Current tracking indicates the object may come within 850 meters (2,800 feet) of the station.

An approach of debris is considered close only when it enters an imaginary “pizza box” shaped region around the station, measuring 0.75 kilometers above and below the station and 25 kilometers on each side (2,460 feet above and below and 15.6 by 15.6 miles). The undocking of the Expedition 29 crew yesterday altered the orbit of the ISS enough so that this object –which had previously not been a threat – is now on its way for a very close pass with the station.

Commander Dan Burbank and Flight Engineers Anton Shkaplerov and Anatoly Ivanishin will awake early and confer with Mission Control on the latest tracking data of the object, and decide by 4:30 a.m. EST (0930 UTC) on Nov. 23 if they should take shelter in the Soyuz.

NASA’s Chief Scientist for Orbital Debris Nicholas Johnson told Universe Today during a previous close conjunction of space debris and the ISS that on average, close approaches to ISS occur about three times a month.

Johnson said that small pieces of debris have already collided with ISS on many occasions, but these debris to date have not affected the safety of the crew or the operation of the mission. “The dedicated debris shields on ISS can withstand particles as large as 1 cm in diameter,” he said.

The crew has taken shelter in the Soyuz vehicles only twice during the 11 years of continual human presence on the ISS.

Schedule

2011 Meteor Showers

Name	Date of Peak	Moon
Quadrantids	night of January 3	New
Lyrids	night of April 21	Rises after midnight
Eta Aquarids	night of May 5	Sets in early evening
Perseids	night of August 12	Full
Draconids	night of October 8	Nearly full
Orionids	night of October 21	Rises after midnight
Leonids	night of November 17	Rises around midnight
Geminids	night of December 13	Just past full

NOTES These are approximate times for the Lower 48 states; actual shower times can vary. Bright moonlight makes it difficult to see all but the brightest meteors.

What are meteor showers?

An increase in the number of meteors at a particular time of year is called a meteor shower.
Comets shed the debris that becomes most meteor showers. As comets orbit the Sun, they shed an icy, dusty debris stream along the comet's orbit. If Earth travels through this stream, we will see a meteor shower. Depending on where Earth and the stream meet, meteors appear to fall from a particular place in the sky, maybe within the neighborhood of a constellation.
Meteor showers are named by the constellation from which meteors appear to fall, a spot in the sky astronomers call the radiant. For instance, the radiant for the Leonid meteor shower is located in the constellation Leo. The Perseid meteor shower is so named because meteors appear to fall from a point in the constellation Perseus.

What are shooting stars?

"Shooting stars" and "falling stars" are both names that people have used for many hundreds of years to describe meteors -- intense streaks of light across the night sky caused by small bits of interplanetary rock and debris called meteoroids crashing and burning high in Earth's upper atmosphere. Traveling at thousands of miles an hour, meteoroids quickly ignite in searing friction of the atmosphere, 30 to 80 miles above the ground. Almost all are destroyed in this process; the rare few that survive and hit the ground are known as meteorites.
When a meteor appears, it seems to "shoot" quickly across the sky, and its small size and intense brightness might make you think it is a star. If you're lucky enough to spot a meteorite (a meteor that makes it all the way to the ground), and see where it hits, it's easy to think you just saw a star "fall."

How can I best view a meteor shower?

If you live near a brightly lit city, drive away from the glow of city lights and toward the constellation from which the meteors will appear to radiate.
For example, drive north to view the Leonids. Driving south may lead you to darker skies, but the glow will dominate the northern horizon, where Leo rises. Perseid meteors will appear to "rain" into the atmosphere from the constellation Perseus, which rises in the northeast around 11 p.m. in mid-August.
After you've escaped the city glow, find a dark, secluded spot where oncoming car headlights will not periodically ruin your sensitive night vision. Look for state or city parks or other safe, dark sites.
Once you have settled at your observing spot, lie back or position yourself so the horizon appears at the edge of your peripheral vision, with the stars and sky filling your field of view. Meteors will instantly grab your attention as they streak by.

How do I know the sky is dark enough to see meteors?

If you can see each star of the Little Dipper, your eyes have "dark adapted," and your chosen site is probably dark enough. Under these conditions, you will see plenty of meteors.

What should I pack for meteor watching?

Treat meteor watching like you would the 4th of July fireworks. Pack comfortable chairs, bug spray, food and drinks, blankets, plus a red-filtered flashlight for reading maps and charts without ruining your night vision. Binoculars are not necessary. Your eyes will do just fine.

New planet

Extra Giant Planet May Have Dwelled in Our Solar System

Within our solar system, an extra giant planet, or possibly two, might once have accompanied Jupiter, Saturn, Neptune and Uranus.
Computer models showing how our solar system formed suggested the planets once gravitationally slung one another across space, only settling into their current orbits over the course of billions of years.
During more than 6,000 simulations of this planetary scattering phase, planetary scientist David Nesvorny at the Southwest Research Institute in Boulder, Colo., found that a solar system that began with four giant planets only had a 2.5 percent chance of leading to the orbits presently seen now. These systems would be too violent in their youth to end up resembling ours, most likely resulting in systems that have less than four giants over time, Nesvorny found.
Instead, a model about 10 times more likely at matching our current solar system began with five giants, including a now lost world comparable in mass to Uranus and Neptune. This extra planet may have been an "ice giant" rich in icy matter just like Uranus and Neptune, Nesvorny explained.

The computer model allowed Nesvorny to create a video of the potential extra planet's departure from our solar system.

Want to Be an Astronaut? NASA Seeking More Space Travelers

Good news for those who think they've got the right stuff: NASA opened the application process for its next astronaut class today (Nov. 15).
The space agency will accept applications for the next class, which will be the 21st group of spaceflyers in its history, through Jan. 27, 2012, then begin a lengthy and highly competitive screening process. NASA expects to announce its final selections in March 2013, and the newly minted spaceflyers will report to Johnson Space Center in Houston for training that summer, agency officials said.
While astronauts in the 21st class won't fly on NASA's now-retired shuttle fleet, there will be plenty of opportunities to get to the International Space Station — and perhaps destinations in deeper space, officials said.
"Some of the astronauts we're recruiting today will be pioneers in our missions to make the first footprints on the surface of Mars," NASA chief Charlie Bolden said during a briefing today.

A thinning astronaut corps
NASA tends to recruit a new astronaut class every two to four years, to maintain a deep enough pool of spaceflyers, officials said.
That pool has been getting more and more shallow recently.
NASA counted 150 active spaceflyers in its ranks in 1999. Many astronauts have retired or left the agency for jobs elesewhere since then, and as a result that number has fallen to 61 in 2011, according to a recent report by the U.S. National Research Council.
Some of those who left the astronaut corps may have been worried about their chances to get back into space soon. For one thing, construction of the $100 billion International Space Station, which required the efforts of many astronauts over the last 13 years, is now complete.
However, the station is slated to operate through at least 2020, and perhaps until 2028. So there will be a need for astronauts to perform research and live aboard the orbiting lab for a long time to come, officials said.
While the shuttle's retirement left NASA completely dependent on Russian Soyuz vehicles to get its spaceflyers to the station and back, that could change by the middle of the decade. The agency is encouraging American private spaceflight firms to take over this taxi service, and it wants at least some of them to be up and running by 2015 or so.
"As we enter this new era of commercial spaceflight, there will be even more opportunities for those of you who want to fly," Bolden said.
For its part, NASA is working to get astronauts to an asteroid by 2025, then on to Mars by the mid-2030s. It's developing a capsule called the Orion Multi-Purpose Crew Vehicle and a huge rocket called the Space Launch System to help get them there.
So the options for future astronauts look to be numerous and varied, according to Bolden.
"Human spaceflight is alive and well at NASA," Bolden said. "With the end of the shuttle program, we're now setting our sights on even more distant horizons. We're once again ready to go where no man or woman has gone before."
Becoming an astronaut
Those interested in applying for NASA's next astronaut class can do so by visiting www.usajobs.gov. Minimum qualifications include a bachelor's degree in science, engineering or mathematics, as well as at least three years of relevant professional experience.

Don't expect to just sail through the application process. The space agency tends to pick literal or figurative high-flyers — people who have experience operating jet aircraft or who are highly accomplished in their respective fields.
"It's very rigorous," said Janet Kavandi, director of flight crew operations at Johnson Space Center.
Rigorous indeed. NASA reviewed more than 3,500 applications before picking nine astronauts for its 20th spaceflyer class in 2009.
After selection, astronauts undergo training that lasts several years and is also extremely challenging, Kavandi added. Not everyone will make it through.

A screenshot of NASA's job announcement for astronaut candidates on the federal USAJobs website.

"If you're selected and you make it through that process, the experience is well worth the wait, I think," Kavandi said. "Anyone who's been to space can say that it was definitely worth all the hard work to get there."