Discovered: An ‘Invisible’ Alien Planet

The best hidden player in a cosmic game of hide-and-seek has just been given away by its own gravitational attraction. For the first time ever, scientists have identified an invisible alien planet by just noticing the gravitational attraction it exerts on another planet, which has been observed. The game was won by the NASA’s Kepler Space Telescope.

An artist's impression of Kepler 19c tugging stealthily at Kepler 19b, as the latter makes its transit across the host star. (Courtesy: David Augilar, Harvard-Smithsonian Center for Astrophysics)

An Alien World

Kepler detected one alien planet as it made a transit across the star it orbits. However, it was noticed that the transit started five minutes early and ended five minutes later than expected. This could only mean that another planetary body tugs on this planet speeding up or delaying its orbital speed. The observed planet has been named Kepler 19b and the unseen planet, Kepler 19c. This is the first time this technique known as transit timing variation or TTV has been used to figure out the existence of an exoplanet. The planetary system is 650 light years away in the constellation Lyra.

Sarah Ballard of Harvard-Smithsonian Center for Astrophysics explains it in naughty-next-door-kid jargon:

It’s like having someone play a prank on you by ringing your doorbell and running away. You know someone was there, even if you don’t see them when you get outside

What about Kepler 19c?

Almost nothing is known about Kepler 19c, except for the fact that it exists. Generally, all planets fall in two categories rocky planets and gas giants. Kepler 19c can be a rocky planet with an orbital period of about 5-7 days (i.e. it is really close to the host star, but light) or it can be a gas giant with an orbital period of 100 or 200 days (i.e. it is far off, but very massive). Both types would be able to exert similar gravitational influence on Kepler 19b.

Kepler 19c hasn’t been seen transiting the parent star, suggesting that the planes of orbit of Kepler 19b and 19c are oblique to one another. Kepler will keep looking. Kepler has done an excellent job in detecting exoplanets, detecting as many as 1235 planets in its first four months of operation.

The excitement and toil of such a search is the same as that of a murder mystery investigation, but happily without a victim. Did you just say, Elementary…? It is not!

Discovered: Two Nearby Supermassive Black Holes Gobbling Up Each Other

This is cannibalism on the cosmic scale. Two black holes have been found by the Chandra X-Ray Telescope gobbling matter from one another. The black holes are in the process of merging with one another. The real excitement is that this is close to home on the scale of the cosmos about 160 million light years away.

The Giants!

The galaxy in the limelight is NGC3393. The two black holes are separated by only 490 light years. One of them has a mass of 30 million suns and other is much smaller at one million solar mass. The bigger one is gobbling up matter surrounding the smaller one.

Chandra's Picture of the twin black holes. (Photo Courtesy: NASA/CXC/SAO/G.Fabbiano et al; Optical: NASA/STScI)

The close proximity of the black holes has also got scientists excited. It is because these supermassive black holes are so close that Chandra could resolve them into two distinct objects. When a black hole accretes matter, i.e. just gathers by sucking the matter around it, the matter gets hot enough to radiate profusely in the X-Ray region. These radiations occur close to the event horizon and this is where Chandra X-Ray Telescope can work its magic. But even Chandra couldn’t have spotted such a double black hole system if it were farther away.

Many that got away?

What we are seeing is really a merger. Black holes merge to become even bigger black holes. It is surprising that NGC3393 still retains the elliptic shape that it originally had. The perturbations occur near the central part and do not propagate throughout the galaxy. NASA scientists think that this is one reason why black hole mergers or double black hole systems have rarely been observed till date. The expected tell-tale signs like galactic perturbations are not really there. Astronomers now want to train Chandra’s eagle-eye on more boring candidates.

The findings were published yesterday in the science journal Nature.

The Universe is not only queerer than we imagine. It is, by all means, queerer than we can possibly imagine!

Discovered: A Huge River That Flows Underneath The Amazon!

This has got to be amongst the weirdest things you’ve heard! Get this: there is actually a river flowing beneath the mighty Amazon!

Scientists have discovered evidence of an underground river, complete with a river basin and features like valleys, flowing 13,000 ft underneath the Amazon. The Brazilian National Observatory, credited with this discovery, has named the river Hamza, after the scientist Valiya Hamza, who has been studying the Amazon for 40 years.

The mouth of the Amazon

A new river – a new type of river!

The Hamza is pretty impressive on its own right, even though it is dwarfed by the Amazon. It is 3,700 miles long, with the Amazon being 4,200 miles long. The Hamza flows along the same slope as the Amazon i.e. from west to east, but at a much slower speed than the Amazon owing to much smoother height gradient underneath the surface.

The river has almost been confirmed, but Hamza is willing to wait till 2014 to get the absolute final confirmation before saying hurrah. The data is primarily obtained from 240 wells drilled into the Amazon region in the 1970’s and 80’s. The wells go down to depths of upto 4,000 meters.

The features of the underground river may be pretty impressive. Scans show that there are vertical drops at 2000 feet depth, but it the river becomes sluggish soon after at greater depths, owing to flat topographical features.

Here’s a video explaining the river in brief.

The effects of this river might have already been apparent for a long time. The salinity levels at the mouth of the Amazon are unexpectedly low and the Brazilian National Observatory claims that the water from the Hamza might be responsible for the unexplained dilution.

Discovered: Unique Planet Completely Made Up of Diamond!

Diamonds are turning out to be more ubiquitous than thought. After we reported that candles burn up diamonds a few days back, we hear of a discovery of a planet, which is completely made up of real diamond. This diamond planet is important in astrophysics, though for a very different reason!

An illustration of what the planet might look like. The yellow circle represents the size of out Sun, for comparison. The entire star-planet system could fit into the sun.

The discovery is too recent for any deep scientific investigation. Astrophysicists think that the planet is actually the core of a star, which died and became a white dwarf. The difference with other white dwarfs in the Universe is that this was orbiting a neutron star.

Lifetime and Death of a Star

A star burns hydrogen, converting it into helium, during its lifetime, known as the main sequence of the star. Once, it runs out of hydrogen it begins to contract, until enough heat builds up to trigger a newer set of reactions, which involves fusing helium to form heavier elements. Once the helium is also snuffed out, the star contracts again. Now, depending on the mass of the star, there might be many such contraction-fusion phases, making higher and higher elements. A mass the size of the Sun will stop somewhere at oxygen and then just settle down, cooling off and becoming a white dwarf. A star with a mass of 1.4 times that of the Sun becomes a neutron star, basically an extremely compact object made up of neutrons. Above 3 solar masses, you get a black hole.

The giant gem!

This new planet is five times the size of Earth with a super-high surface pressure. The extremely high surface pressure leads scientists to suspect that the entire planet has been crystallized into diamond. The planet orbits a rapidly pulsating neutron star that radiates a pulsar. Named PSR J1719-1438, the pulsar has a rotation rate of 10000 rotations per minute! It is located at a distance of 4000 light years from Earth!

All that sparkles… also pulsates

This system is not only interesting for being the biggest piece of diamond known! This is only the second time such a system, i.e. one which involves white dwarf orbiting a pulsar, has been discovered. The planet is also larger than the star’, as generally white dwarfs are bigger than neutron stars in size.

So there is another piece of diamond that you’ll never get your hands on! Thank your pulsars that no one else is getting it either!

Discovered: A VERY Dark Exoplanet, Which Reflects Just 1% Of Incident Radiation

It’s dark out there, really dark out there. Astronomers have stumbled upon an object which reflects just 1% of the incident radiation and absorbs 99%. It is the darkest astronomical body found. Not only that, it is the darkest object known to man even surpassing carbon nanotubes, which can be prepared to be extra dark. It does emit a faint reddish glow, though.

An artist's rendition of the dark planet. (Courtesy: David A. Augilar)

About the Oddity

The size of the planet is more than Jupiter’s, but orbits the central star at a distance of just 3 million miles, more than 30 times closer than the distance between Earth and Sun. It orbits a star named GSC 03549-02811, which is located 750 light years away. It is one of the so called Kepler Planets, discovered and now being viewed by the Kepler spacecraft.

Comparison in size of TrES-2b with Jupiter (Courtesy: Wikipedia Commons)

In comparison to this planet, Earth reflects about 35% of its radiation. Venus reflects the highest amongst all the Solar System, reflecting about 65% of the total incident radiation.

It’s Hot too!

The new object, exotically named TrES-2b or Kepler-1b, has a record 1800 Degree Celsius as its surface temperature, due to the intense greenhouse effects produced by the thick heat-absorbing atmosphere. The atmosphere contains sodium, potassium and titanium oxide, which all help in the absorption. The effect is a runaway heating of the planet, somewhat balanced only by the amount of heat radiated by the clouds into space. The high temperature also prevents ammonia clouds from forming, which would have helped in the reflection. This is a really greenhouse planet.

This is the first time such an extreme object has been discovered. Despite the atmospheric composition, astronomers cannot justify how such a planet can exist. Here’s another juicy, dark mystery for science.

Discovered : A Belt of Antimatter Surrounding Earth

Anti-particles are not as exotic as many think and here’s further proof. The PAMELA spacecraft has detected a ring of anti-protons around the Earth, confined in that region by Earth’s magnetic field. These may be confined in that small region for hours before annihilating with matter and producing radiation.

This ground-breaking discovery was reported by PAMELA spacecraft recently. PAMELA, acronym for Payload for Anti-Matter Exploration and Light-nuclei Astrophysics, is a satellite that was launched to further cosmic ray astrophysics on 15th June 2006. It was specifically built to focus on the occurrence and interactions of positrons (anti-electrons) and anti-protons in the space around Earth.

The PAMELA spacecraft

Some theoretical considerations

Anti-matter is a theoretical necessity, which can be deduced from the symmetry of theories in physics. It was first predicted by the great Paul Dirac in 1931, following the interpretation of results given by his own equation (unsurprisingly called, the Dirac Equation) to describe the electron. His wild prediction of the positron was soon experimentally verified the following year by Carl Anderson, who detected it in his lab. (Remember, that the neutron was not yet known. It was also discovered in 1932 late in the year.) The scientific impact and importance can be gauged from the fact that Anderson went onto win the Nobel Prize in 1936, just four years after the discovery. Now, we know that every particle must have its anti-particle.

When particles and anti-particles collide, they annihilate producing (two) gamma rays. As always in physics, the reverse can also happen. Given certain conditions, a gamma ray can give rise to two particles a particle and an anti-particle obeying Einstein’s famous equation E=mc2. (Due to other strong constraints imposed by symmetries of physics, two particles or two anti-particles cannot be produced.)

The Van Allen Radiation Belts (Courtesy: Addison Wesley Longman)

In our atmosphere too, the same phenomenon happens. High energy cosmic rays bombard the Earth’s atmosphere producing matter and anti-matter particles. These can be kept separated out from each other due to the presence of Earth’s magnetic field, since moving particles of opposite charge behave very differently in magnetic fields. Furthermore, magnetic fields can confine these particles in pockets. They can remain stable for hours on average, before encountering matter particles and annihilating. Theoreticians have long predicted the presence of anti-protons in the Van Allen Belts (belts of charged particles surrounding Earth), in addition to positrons, because of the high energy of the bombarding cosmic rays. Anti-protons are much more massive than anti-electrons and thus require more energy to be produced. Most radiation can produce electron-positron pairs, but do not have enough energy to produce proton-antiproton pairs.

Enter PAMELA

PAMELA collected data over 850 days from the South Atlantic anomaly (a region over the South Atlantic ocean, where the Van Allen belts come closest to the Earth’s surface) and confirmed this theoretical prediction.

As this news spreads, there will be inevitable attempts at grabbing eyeballs by projecting this as the new cheap, easily available energy source. You can lend an ear to that at your own risk.

Discovered: A Super Massive Black Hole Weighing As Much As Two Billion Suns

This is a big astrophysical find, literally big! The Chandra X-Ray telescope has detected the signature of a supermassive black hole by observing the hot gases falling into it. The estimated mass of the black hole is a huge 2 Billion times the mass of the Sun!

The compact object lies at the heart of the galaxy known as NGC 3115, located at a distance of 32 million light-years away from Earth, making this the closest billion-solar-mass object to Earth. Astronomers have long been interested in the activity in this region, especially the gas falling into the central object. There have been various observations in the various frequencies, but this is only the first time when the X-Ray signatures have been clearly observed. The Chandra data suggests a huge mass for the black hole, given the temperature of the glowing gas falling into it. Only if the gas glows extremely intensely, does it give off X-Rays. NGC 3115 is about a million times brighter in X-Rays than in visible light.

How They Found Out the Mass

There is a term, called Bondi radius, named after the astrophysicist Hermann Bondi, which describes how the gas is affected by the black hole gravity. It is defined as the distance at which the gravity first starts dominating the random kinetic motion of the gas and the gas starts spiraling into the black hole.

The NGC 3115 galaxy

The data from the Chandra telescope suggests that the Bondi Radius is 700 light years away from the black hole!! In comparison, the closest star to Earth, after the Sun, is about 4 light years away. This gives an estimate of the mass of the black hole and the calculation suggests 2 billion solar masses!!

Any Use?

This finding is not only one for public consumption, but also scientific fodder. It may help to explain how matter flows into a black hole, as a tremendous amount of data is available due to the luminosity of the black hole.

It also brings up questions. Scientists still don’t know how such extremely massive black holes stay dim. As Dr. Jimmy Irwin, assistant professor of University of Alabama’s Physics Department says:

A leading mystery in astrophysics is how the area around massive black holes can stay so dim, when there’s so much fuel available to light up.

It is often said that astronomy is a humbling science. This just confirms that saying.

Discovered: A Small Asteroid Which Shares Orbit With Earth

A tiny asteroid, having roughly the same orbit as the Earth, has been discovered. The companion asteroid is about 300 yards across. It leads the Earth as both the objects orbit the Sun. However, the asteroid has variable speed and a more eccentric orbit, often leading the Earth by as much as half-an-orbit.

The finding is due to work by Martin Connors of Canada’s Athabasca University and his colleagues. The findings have been published in the journal Nature.

The new object

The asteroid has been named 2010 TK7, and was discovered last year by NASA’s WISE satellite. This is the first time such a companion rocky body has been discovered to share the orbit with Earth. Many such bodies are known to either share the orbit with Jupiter or Saturn or become their moons. In fact, the fate of many objects sharing orbits with such large planets is that they eventually become satellites.

Asteroids are giant rocks in space, orbiting the Sun, believed to be remnants of the planet forming era. These are leftovers, those chunks which did not form planets. Among the big asteroids in the Solar System is Ceres, which has its own orbit between Mars and Jupiter. It is believed to be remnants of a planet which broke up, probably after being struck by a large comet.

Earth is not alone

Rocky bodies which share an orbit with a planet are called Trojans’. This object 2010 TK7 is the first Trojan found for Earth. Jupiter is known to have about 5000 Trojans, rocks brought to it by its intense gravitational pull. Mars, Neptune and Saturn also have their share, though the number is much less than that of Jupiter.

Trojans around Jupiter (green dots)

There is no fear of an asteroid crashing onto the Earth in the immediate future. It’s just a harmless body accompanying the Earth on its annual journey around the Sun.

Hubble Discovers a Fourth New Moon of Pluto

Hubble has done it again. It has captured a hitherto unknown fourth moon of Pluto, the dwarf planet. The three known moons of Pluto are Charon, Nix and Hydra. The fourth one, discovered just recently on 3rd July, 2011, and officially announced today by NASA and SETI, is temporarily known as P4.

Pluto was stripped of its planet tag on 24th August, 2006 and was relegated to the status of dwarf planet’ along with Eris and Ceres. Eris is, in fact, more massive than Pluto.

An animation showing Pluto. Done using images from Hubble (Photo: NASA)

Charon is the most well-known moon of Pluto and was the only moon discovered till 2005. It is quite large, with a size comparable with Pluto. In 2005, two newer moons were discovered and named Nix and Hydra. It is not known whether this recently discovered moon, P4, was there at the time of the discovery of the previous moons or was captured more recently.

The photo captured by Hubble. (Courtesy: SETI/NASA)

It was due to the wonder called the Hubble Space Telescope that a cold object, tiny in size and moving fast around a very distant body could be photographed. Mark Showalter of SETI Institute in Mountain View, California has this to say:

I find it remarkable that Hubble’s cameras enabled us to see such a tiny object so clearly from a distance of more than 3 billion miles (5 billion km).

The diameter of the new moon is just 8-21 miles, while Charon, by comparison, is a giant at 648 miles. Nix and Hydra are both about 50 miles in diameter.

NASA aims to discover more about the body least known to man with the upcoming New Horizons mission. New Horizons will hope to fly past Pluto in 2015, using inputs from Hubble’s photos to chart out its path.