Space

For the first time, a team of international researchers has found a way to view the accretion disks surrounding black holes and verify that their true electromagnetic spectra match what astronomers have long predicted they would be.

A black hole and its bright accretion disk have been thought to form a quasar, the powerful light source at the center of some distant galaxies. Using a polarizing filter, the research team, which included Robert Antonucci and Omer Blaes, professors of physics at the University of California, Santa Barbara, isolated the light emitted by the accretion disk from that produced by other matter in the vicinity of the black hole.


Imagine having three clocks in your house, each chiming at a different time.

Astronomers have found the equivalent of three out-of-sync "clocks" in the ancient open star cluster NGC 6791. The dilemma may fundamentally challenge the way astronomers estimate cluster ages, researchers said.

Using NASA's Hubble Space Telescope to study the dimmest stars in the cluster, astronomers uncovered three different age groups. Two of the populations are burned-out stars called white dwarfs. One group of these low-wattage stellar remnants appears to be 6 billion years old, another appears to be 4 billion years old. The ages are out of sync with those of the cluster's normal stars, which are 8 billion years old.


Continuing from the prior article... “The Sun Ain’t Yeller”, cries the heliochromologist.  Undaunted by tradition, dogma, or tens of thousands of erroneous magazine and textbook images of our Sun, heliochromology, a colorful heterodox, is winning the day because the Sun is what it is, color and all, regardless of other’s puerile incognizance. 

The answer is not a vague, subjective one, but an objective one, as sure as red apples are red.  Heliochromology is our path to enlightenment that will bring resolve to this color conundrum -- a subtle polemic that has been dormant to all of astronomy for hundreds, nay thousands, nay nay, tens of thousands of years, perhaps since mankind first discovered the Sun and its daily color metamorphosis. 

We know not who the sagacious sapien may have been who indubitably made the first astronomical discovery of all time – the Sun.

NASA's sun-focused STEREO spacecraft unexpectedly detected particles from the edge of the solar system last year, allowing University of California, Berkeley, scientists to map for the first time the energized particles in the region where the hot solar wind slams into the cold interstellar medium.

Mapping the region by means of neutral, or uncharged, atoms instead of light "heralds a new kind of astronomy using neutral atoms," said Robert Lin, UC Berkeley professor of physics and lead for the suprathermal electron sensor aboard STEREO. "You can't get a global picture of this region, one of the last unexplored regions of the heliosphere, any other way because it is too tenuous to be seen by normal optical telescopes."

The heliosphere is a volume over which the effects of the solar wind extend, stretching from the sun to more than twice the distance of Pluto. Beyond its edge, called the heliopause, lies the relative quiet of interstellar space, at about 100 astronomical units (AU) - 100 times the Earth-sun distance.


If you're a long-time reader of this site, you might get the idea that Albert Einstein was a pretty smart guy - that comes across because he tends to proven right a lot even today.

PSR J0737-3039A/B is a unique system of two dead stars, pulsars, and one of the pair is 'wobbling' in space just like a spinning top, according to a team of researchers. The effect, called precession, was predicted by Albert Einstein and is yet another confirmation of his theory.

The binary pulsars were formed when a pair of massive stars exploded and their cores collapsed to create objects whose mass is greater than that of our Sun, but compressed to the size of a city. They are spinning at incredible speeds and emit powerful beams of radio waves which sweep across our radio-telescopes like cosmic lighthouses producing regular pulses of energy - hence their name, pulsars. PSR J0737-3039A/B is the only known system in our galaxy where two pulsars are locked into such close orbit around one another - the entire system could fit inside our Sun.


A few years ago Voyager 1 entered the final frontier, that place where the solar wind becomes denser and hotter and pressure from gas between stars causes it to slow - the Termination Shock.

Now that Voyager 2 has reached its edge of the solar system, just under 7 billion miles from Earth, it has confirmed what astrophysicists had believed - the conflict between the solar wind and the interstellar wind has made that part of the solar system slightly squashed.


Homer's Odyssey, be it history or fiction, had one potentially true part that has fascinated readers throughout the ages - namely whether Odysseus returned home to experience a total solar eclipse.

Total eclipses, when the moon briefly but completely blocks the sun, happen pretty rarely. In fact, they're so rare that if what Homer describes is truly an eclipse, it could potentially help historians date the fall of Troy, which was purported to occur around the time of the events described in the Iliad and the Odyssey.

After arguing about the point for hundreds of years, historians, astronomers and classicists finally agreed that there was no corroborating evidence and tabled the discussion. Now, Marcelo O. Magnasco, head of the Laboratory of Mathematical Physics at Rockefeller, and Constantino Baikouzis of the Proyecto Observatorio at the Observatorio Astronómico in La Plata, Argentina, believe they have found some overlooked passages that, taken together, may shed new light on the timing of an epic journey.

Two stars, each with the same mass and in orbit around each other, are twins that one would expect to be identical. So astronomers were surprised when they discovered that twin stars in the Orion Nebula, a well-known stellar nursery 1,500 light years away, were not identical at all. In fact, these stars exhibited significant differences in brightness, surface temperature and possibly even size.

The study published in the June 19 Nature suggests that one of the stars formed significantly earlier than its twin. Because astrophysicists have assumed that binary stars form simultaneously, the discovery provides an important new challenge for today's star formation theories, forcing theorists to reexamine their models to see if the models can indeed produce binaries with stars that form at different times.


Today, at an international conference, a team of European astronomers announced they have found a triple system of 'super-Earths' around the star HD 40307, called such because they are more massive than the Earth but less massive than Uranus and Neptune (about 15 Earth masses.)

These super-Earths are around a rather normal star, which is slightly less massive than our Sun, and is located 42 light-years away towards the southern Doradus and Pictor constellations.

Looking at their entire sample studied with HARPS, the astronomers count a total of 45 candidate planets with a mass below 30 Earth masses and an orbital period shorter than 50 days. This implies that one solar-like star out of three harbors such planets.



Almost two years after the International Astronomical Union (IAU) General Assembly introduced the category of dwarf planets, the IAU, as promised, has decided on a name for transneptunian dwarf planets similar to Pluto.

The name plutoid was proposed by the members of the IAU Committee on Small Body Nomenclature (CSBN), accepted by the Board of Division III, by the IAU Working Group for Planetary System Nomenclature (WGPSN) and approved by the IAU Executive Committee at its recent meeting in Oslo, Norway.

Plutoids are celestial bodies in orbit around the Sun at a distance greater than that of Neptune that have sufficient mass for their self-gravity to overcome rigid body forces so that they assume a hydrostatic equilibrium (near-spherical) shape, and that have not cleared the neighbourhood around their orbit. The two known and named plutoids are Pluto and Eris. It is expected that more plutoids will be named as science progresses and new discoveries are made.