Blue Moon - Chief guest
Niharika
Urvashi
Pranav
Kinjal
Naphees
Abhishek
Club Members
Club Members
Vintage Telescope
Thanks to all members who join the star party & enjoyed the event.
Regards DMR
Friday, August 31, 2012
Blue Moon - Today
The second full moon for the month of August 2012 will occur on Friday the 31st, which is commonly referred to as a 'blue moon'.
Dawn Spacecraft
NASA's Dawn spacecraft is on track to become the first probe to orbit and study two distant solar system destinations, to help scientists answer questions about the formation of our solar system. The spacecraft is scheduled to leave the giant asteroid Vesta on Sept. 4 PDT (Sept. 5 EDT) to start its two-and-a-half-year journey to the dwarf planet Ceres.
NASA Curiosity Rover Begins Eastbound Trek on Martian Surface
Soil clinging to the right middle and rear wheels of NASA's Mars rover Curiosity can be seen in this image taken by the Curiosity's Navigation Camera after the rover's third drive on Mars. Image credit: NASA/JPL-Caltech
NASA's Mars rover Curiosity has set off from its landing vicinity on a trek to a science destination about a quarter mile (400 meters) away, where it may begin using its drill.
The rover drove eastward about 52 feet (16 meters) on Tuesday, its 22nd Martian day after landing. This third drive was longer than Curiosity's first two drives combined. The previous drives tested the mobility system and positioned the rover to examine an area scoured by exhaust from one of the Mars Science Laboratory spacecraft engines that placed the rover on the ground.
Astronauts Complete Second Expedition 32 Spacewalk
Flight Engineer Akihiko Hoshide rides on the station's robotic arm. Credit: NASA TV
ASA Flight Engineer Sunita Williams and Japan Aerospace Exploration Agency Flight Engineer Akihiko Hoshide completed the second spacewalk of the Expedition 32 mission at 4:33 p.m. EDT Thursday. They began the spacewalk at 8:16 a.m.
During the spacewalk, Williams and Hoshide were unable to install a new Main Bus Switching Unit (MBSU) on the International Space Station’s s-zero truss. After removing and stowing the failed unit, the spacewalkers had difficulties driving the bolts to secure the replacement switching unit in the s-zero truss.
Thursday, August 30, 2012
Saturn and its Largest Moon Reflect Their True Colors
A giant of a moon appears before a giant of a planet undergoing seasonal changes in this natural color view of Titan and Saturn from NASA's Cassini spacecraft.
Titan, Saturn's largest moon, measures 3,200 miles, or 5,150 kilometers, across and is larger than the planet Mercury. Cassini scientists have been watching the moon's south pole since a vortex appeared in its atmosphere in 2012. See PIA14919 and PIA14920 to learn more about this mass of swirling gas around the pole in the atmosphere of the moon.
Astronauts at Work Outside Space Station
NASA Flight Engineer Sunita Williams and Japan Aerospace Exploration Agency Flight Engineer Akihiko Hoshide began the second spacewalk of the Expedition 32 mission at 8:16 a.m. EDT Thursday.
During the scheduled 6.5-hour excursion, the spacewalkers will replace a faulty power relay unit on the International Space Station's truss, rig power cables for the arrival late next year of a Russian laboratory module, replace a failing robotic arm camera and install a thermal cover on a docking port.
Williams has conducted 4 previous spacewalks and is wearing a spacesuit bearing red stripes. Hoshide, wearing a spacesuit with no stripes, is conducting his first spacewalk. He is the third Japanese astronaut in history to conduct a spacewalk. The spacewalk is the 164th in support of station assembly and maintenance. This is the first U.S.-based spacewalk since July 2011.
Over the past couple of weeks, Williams and Hoshide completed a variety of tasks in anticipation of the spacewalk including resizing their U.S. extravehicular mobility unit spacesuits, conducting routine spacesuit maintenance, configuring spacewalk equipment and conducting a suited “dry run” check.
The first Expedition 32 spacewalk was performed by Commander Gennady Padalka and Flight Engineer Yuri Malenchenko on Aug. 20. The primary task during their 5-hour, 51-minute excursion was the move of the Strela-2 cargo boom from the Pirs docking compartment to the Zarya module. Other tasks included the installation of micrometeoroid debris shields on the exterior of the Zvezda service module and the deployment of a small science satellite.
Source: NASA
NASA LAUNCHES RADIATION BELT STORM PROBES MISSION
NASA's Radiation Belt Storm Probes (RBSP), the first
twin-spacecraft mission designed to explore our planet's radiation belts,
launched into the predawn skies at 4:05a.m. EDT Thursday from Cape Canaveral
Air Force Station, Fla.
"Scientists will learn in unprecedented detail how
the radiation belts are populated with charged particles, what causes them to
change and how these processes affect the upper reaches of the atmosphere
around Earth," said John Grunsfeld, associate administrator for NASA's
Science Mission Directorate at Headquarters in Washington. "The
information collected from these probes will benefit the public by allowing us
to better protect our satellites and understand how space weather affects
communications and technology on Earth."
Blue Moon - Facts
With a so-called "blue moon" set to rise in the night sky this Friday (Aug. 31), you may find yourself wondering: Just what is a blue moon, exactly? And where does the term come from?
Somewhat confusingly, the answers have nothing to do with the moon's color. The "blue moon" tale is a convoluted one, with much of the action taking place in the relatively recent past.
In 1946, "Sky and Telescope" magazine traced the term to the "Maine Farmer's Almanac," where it apparently referred to the third full moon in a season that contains four full moons instead of the usual three.
NASA's WISE Survey Uncovers Millions of Black Holes
NASA's Wide-field Infrared Survey Explorer (WISE) mission has led to a bonanza of newfound supermassive black holes and extreme galaxies called hot DOGs, or dust-obscured galaxies.
With its all-sky infrared survey, NASA's Wide-field Infrared Survey Explorer, or WISE, has identified millions of quasar candidates. Image credit: NASA/JPL-Caltech/UCLA
Images from the telescope have revealed millions of dusty black hole candidates across the universe and about 1,000 even dustier objects thought to be among the brightest galaxies ever found. These powerful galaxies, which burn brightly with infrared light, are nicknamed hot DOGs.
"WISE has exposed a menagerie of hidden objects," said Hashima Hasan, WISE program scientist at NASA Headquarters in Washington. "We've found an asteroid dancing ahead of Earth in its orbit, the coldest star-like orbs known and now, supermassive black holes and galaxies hiding behind cloaks of dust."
Curiosity Begins 1st Long Martian Drive
Curiosity headed off eastward Tuesday (Aug. 28) toward a spot called Glenelg, where three different types of terrain come together in one place. The 52-foot (16-meter) drive marks the rover's first big move away from "Bradbury Landing," where Curiosity touched down on the night of Aug. 5.
"This drive really begins our journey toward the first major driving destination, Glenelg, and it's nice to see some Martian soil on our wheels," mission manager Arthur Amador, of NASA's Jet Propulsion Laboratory in Pasadena, Calif., said in a statement. "The drive went beautifully, just as our rover planners designed it."
Curiosity had made two short drives before Tuesday's big move. These previous jaunts tested the rover's mobility system and positioned it to study a patch of ground scoured by Curiosity's rocket-powered "sky crane" descent stage, which lowered the six-wheeled robot to the Martian surface on cables.
Wednesday, August 29, 2012
Signing out: Armstrong autographs under hammer
A series of autographs of Neil Armstrong, the first man to walk on the moon, will go under the hammer this week with auctioneers wondering if the sky's the limit for the prized signatures.
Interest is likely to be intense, following Armstrong's death last weekend at age 82, according to the Los Angeles auction house behind the sale.
"Neil Armstrong was very generous to those who sought out his autograph because they were inspired by the Apollo 11 mission," said Nate Sanders, owner of Nate D Sanders Auctions.
"When he realized that some people just requested it in order to sell it ... he became disillusioned with autograph seekers. He didn't believe in charging for his autograph, so at this time he suddenly stopped signing altogether.
Artificial Universe Similar to Ours Built with Supercomputer
Building a universe from scratch that brims with galaxies resembling those around us is now possible on supercomputers for the first time, researchers say.
This still frame is taken from the Arepo-generated animation shown above. It demonstrates Arepo's key ability to produce realistic spiral galaxies. Previous simulations tended to yield blobby galaxies lacking distinct spiral structure. Posted Aug. 28, 2012.
CREDIT: CfA/UCSD/HITS/M. Vogelsberger (CfA) & V. Springel (HITS)
Our galaxy, the Milky Way, is a spiral galaxy with a broad disk and outstretched arms, as are many in our cosmic neighborhood, such as Andromeda, the Pinwheel and the Whirlpool galaxies. Spiral galaxies are common, but past computer models that aimed to accurately simulate the birth and evolution of the universe over billions of years had trouble creating them. Instead, they often generated lots of blobby galaxies clumped into balls.
Hubble Telescope's Hidden Photo Treasures: 2012 Winner
First Prize/Winner of the Public Vote: Josh Lake, Star-Forming Region NGC 1763Credit: Josh Lake/NASA & ESAJosh Lake (USA) submitted a stunning image of NGC 1763, part of the N11 star-forming region in the Large Magellanic Cloud. ESA/Hubble had previously published an image of an area just adjacent to this (heic1011), based on observations by the same team. Josh took a different approach, producing a bold two-colour image which contrasts the light from glowing hydrogen and nitrogen. The image is not in natural colours — hydrogen and nitrogen produce almost indistinguishable shades of red light that our eyes would struggle to tell apart — but Josh’s processing separates them out into blue and red, dramatically highlighting the structure of the region. As well as narrowly topping the jury’s vote, Josh Lake also won the public vote.
Source: Space.com
Source: Space.com
Orbiting in the Habitable Zone of Two Sun
This diagram compares our own solar system to Kepler-47, a double-star system containing two planets, one orbiting in the so-called "habitable zone." This is the sweet spot in a planetary system where liquid water might exist on the surface of a planet.
Credit: NASA/JPL-Caltech/T. Pyle
NASA's Kepler Discovers Multiple Planets Orbiting a Pair of Stars
Coming less than a year after the announcement of the first circumbinary planet, Kepler-16b, NASA's Kepler mission has discovered multiple transiting planets orbiting two suns for the first time. This system, known as a circumbinary planetary system, is 4,900 light-years from Earth in the constellation Cygnus.
This discovery proves that more than one planet can form and persist in the stressful realm of a binary star and demonstrates the diversity of planetary systems in our galaxy.
The two planets of Kepler-47, the first transiting circumbinary system -- a system with more than one planet orbiting a pair of stars. Kepler-47b, on the right, has three times the radius of earth and orbits the pair of stars in less than 50 days while Kepler-47c is thought to be a gaseous giant, slightly larger than Neptune with an orbital period of 303 days.
This discovery proves that more than one planet can form and persist in the stressful realm of a binary star and demonstrates the diversity of planetary systems in our galaxy.
Sharing the Light of Two Suns
This artist's concept illustrates Kepler-47, the first transiting circumbinary system -- multiple planets orbiting two suns – 4,900 light-years from Earth, in the constellation Cygnus. The system was detected by NASA's Kepler space telescope, which measures minisucule changes in the brightness of more than 150,000 stars to search for planets that pass in front of or 'transit' their host star.
As seen from our vantage point on Earth, the two orbiting stars regularly eclipse each other every 7.5 days. One star is similar to the sun in size, but only 84 percent as bright. The second star is diminutive, measuring only one-third the size of the sun and less than one percent as bright.
Two planets also eclipse, or transit, the host stars. The inner planet, Kepler-47b, orbits the pair of stars in less than 50 days. At three times the radius of Earth, it is the smallest known transiting circumbinary planet.
Seen in the foreground, the outer planet, Kepler-47c, orbits its host pair every 303 days, placing it in the so-called "habitable zone," the region in a planetary system where liquid water might exist on the surface of a planet. While not a world hospitable for life, Kepler-47c is thought to be a gaseous giant, slightly larger than Neptune, where an atmosphere of thick bright water-vapor clouds might exist.
Credit: NASA/JPL-Caltech/T. Pyle
Bremsstrahlung - Definition
Bremsstrahlung
Bremsstrahlung is electromagnetic radiation produced
by the deceleration of a charged particle when deflected by
another charged particle, typically an electron by an atomic
nucleus. The moving particle loses kinetic
energy, which is converted into a photon because energy is conserved. The term is also used to refer
to the process of producing the radiation. Bremsstrahlung has a continuous spectrum, which becomes more intense and
shifts toward higher frequencies as the change of the energy of the accelerated
particles increases.
Strictly speaking, bremsstrahlung
is any radiation due to the acceleration of a charged particle, which includes synchrotron radiation and cyclotron radiation; however, it is frequently used
in the more narrow sense of radiation from electrons stopping in matter.
Bremsstrahlung
produced by a high-energy electron deflected in the electric field of an atomic
nucleus
Bremsstrahlung emitted from plasma is sometimes referred to as free-free radiation. This refers
to the fact that the radiation in this case is created by charged particles
that are free both before and after the deflection (acceleration) that
causes the emission.
Source: wikipedia, NASA
Brahe, Tycho (1546 - 1601) - Definition
Brahe,
Tycho (1546 - 1601)
Tycho Brahe (14 December 1546 – 24 October 1601),
born Tyge Ottesen Brahe,was a Danish nobleman known for
his accurate and comprehensiveastronomical
and planetary observations.
He was born in Scania, then part of Denmark, now part of modern-day
Sweden. Tycho was well known in his lifetime as an astronomer and alchemist.
His work as an astronomer was
remarkably accurate for his time. Most importantly, it had a most significant
impact which remains today.
In his De nova stella (On the new star) of 1573, he refuted
the Aristotelian belief in an unchanging celestial realm. His
precise measurements indicated that "new stars" (novae or also now known as supernovae), in
particular that of
1572, lacked the parallaxexpected in sub-lunar phenomena, and
were therefore not "atmospheric" tail-less comets as previously believed, but occurred above
the atmosphere and moon. Using similar measurements he showed that comets were
also not atmospheric phenomena, as previously thought, and must pass through
the supposed "immutable" celestial
spheres.
Source: wikipedia, NASA
Boltzmann constant; k (l. Boltzmann) - Definition
Boltzmann constant
A constant which describes the relationship between
temperature and kinetic energy for molecules in an ideal gas. It is equal to
1.380622 x 10-23 J/K.
The Boltzmann constant (k or kB)
is the physical
constant relating energy at the individual particle level with temperature, which
must necessarily be observed at the collective or bulk level. It is the gas
constant R divided by the Avogadro
constant NA.
Boltzmann's
grave in the Zentralfriedhof, Vienna, with
bust and entropy formula.
Source: wikipedia, NASA
Bolometric Luminosity - Definition
Bolometric
Luminosity
The total energy radiated by an object at all wavelengths,
usually given in joules per second (identical to watts).
Luminosity is generally understood as a measurement of brightness. Each
discipline, however, defines the term differently, depending on what is being
measured.
Image
of galaxy NGC 4945 showing the
huge luminosity of the central few star clusters, suggesting there are 10 to
100 supergiant stars in each of these, packed into regions just a few parsecs across.
In astronomy, luminosity measures
the total amount of energy emitted by a star or other astronomical object in joules per second, which are watts. A watt
is one unit of power, and so just as a light
bulb is
measured in watts, so too is the Sun, the
latter having a total power output of 3.846×1026 W. It is
this number which constitutes the basic metric used in astronomy and is known
as 1 solar
luminosity.Radiant power, however, is not the only way to conceptualize brightness, so
other metrics are also used. The most common is apparent magnitude, which is the perceived brightness of an object from an observer on Earth at visible wavelengths.
Source: wikipedia, NASA
Blueshift - Definition
Blueshift
A blueshift is any decrease
in wavelength (increase in
frequency); the opposite effect is referred to as redshift. In visible light, this shifts the colour from the red end of the
spectrum to the blue end. The term also applies when photons outside the
visible spectrum (e.g. x-rays and radio
waves) are shifted toward shorter wavelengths, as well as to shifts in the de Broglie wavelength of particles.
Blueshift is most commonly caused by relative motion toward the observer,
described by the Doppler effect. An observer in
a gravity well will also see infalling radiation gravitationally blueshifted,
described by General
Relativity in the same way as gravitational
redshift.
In a contracting universe, cosmological
blueshift would be observed; the expanding universe gives a cosmological redshift, and the
expansion is observed to be accelerating.
Source: wikipedia, NASA
Blackbody Radiation - Definition
Blackbody Radiation
Black-body radiation is the type of electromagnetic radiation within or surrounding a body in thermodynamic equilibrium with its environment, or emitted by a black
body (an
opaque and non-reflective body) held at constant, uniform temperature. The
radiation has a specific spectrum and intensity that depends only on the
temperature of the body.
A perfectly insulated enclosure
that is in thermal equilibrium internally contains black body radiation and
will emit it through a hole made in its wall, provided the hole is small enough
to have negligible effect upon the equilibrium.
A black body at room temperature
appears black, as most of the energy it radiates is infra-red and cannot be perceived by the human eye. At
higher temperatures, black bodies glow with increasing intensity and colors
that range from dull red to blindingly brilliant blue-white as the temperature
increases.
Although planets and stars are
neither in thermal equilibrium with their surroundings nor perfect black
bodies, black body radiation is used as a first approximation for the
energy they emit.Black
holes are
near-perfect black bodies, and it is believed that they emit black-body
radiation (called Hawking
radiation), with a temperature that depends on the mass of the hole.
The term black body was introduced by Gustav
Kirchhoff in 1860.
When used as a compound adjective, the term is typically written
as hyphenated, for example, black-body
radiation, but sometimes also as one word, as inblackbody radiation.
Black-body radiation also is called complete
radiation ortemperature
radiation or thermal radiation.
Source: wikipedia, NASA
Blackbody Temperature - Definition
Blackbody Temperature
The
temperature of an object if it is re-radiating all the thermal energy that has
been added to it; if an object is not a blackbody radiator, it will not
re-radiate all the excess heat and the leftover will go toward increasing its
temperature.
A black body is an idealized physical
body that
absorbs all incident electromagnetic radiation,
regardless of frequency or angle of incidence.
A black body in thermal equilibrium (that is,
at a constant temperature) emits electromagnetic radiation called black-body radiation. The radiation is emitted
according to Planck's
law, meaning that it has a spectrum that is
determined by the temperature alone (see figure at right), not by the
body's shape or composition.
A black body in thermal
equilibrium has two notable properties:
1.
It is an ideal emitter: it emits as much or more energy at every
frequency than any other body at the same temperature.
2.
It is a diffuse emitter: the energy is radiated isotropically,
independent of direction.
Source: wikipedia, NASA
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