Science is the poetry of Nature.

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Posts tagged "astronomy"

Zodiacal Light

Pre dawn Zodical light (upper left) and Aurora (top) near Tensleep Wyoming on 8-27. - DakotaLapse

(via afro-dominicano)


Hubble Helps Astronomers Find Smallest Known Galaxy With Supermassive Black Hole

Astronomers using the NASA/ESA Hubble Space Telescope have found a monster lurking in a very unlikely place.

New observations of the ultracompact dwarf galaxy M60-UCD1 have revealed a supermassive black hole at its heart, making this tiny galaxy the smallest ever found to host a supermassive black hole.

This suggests that there may be many more supermassive black holes that we have missed, and tells us more about the formation of these incredibly dense galaxies. The results will be published in the journal Nature on 18 September 2014.

Lying about 50 million light-years away, M60-UCD1 is a tiny galaxy with a diameter of 300 light-years — just 1/500th of the diameter of the Milky Way. Despite its size it is pretty crowded, containing some 140 million stars. While this is characteristic of an ultracompact dwarf galaxy (UCD) like M60-UCD1, this particular UCD happens to be the densest ever seen.

Despite their huge numbers of stars, UCDs always seem to be heavier than they should be. Now, an international team of astronomers has made a new discovery that may explain why — at the heart of M60-UCD1 lurks a supermassive black hole with the mass of 20 million Suns.

"We’ve known for some time that many UCDs are a bit overweight. They just appear to be too heavy for the luminosity of their stars," says co-author Steffen Mieske of the European Southern Observatory in Chile. "We had already published a study that suggested this additional weight could come from the presence of supermassive black holes, but it was only a theory. Now, by studying the movement of the stars within M60-UCD1, we have detected the effects of such a black hole at its centre. This is a very exciting result and we want to know how many more UCDs may harbour such extremely massive objects."

The supermassive black hole at the centre of M60-UCD1 makes up a huge 15 percent of the galaxy’s total mass, and weighs five times that of the black hole at the centre of the Milky Way. “That is pretty amazing, given that the Milky Way is 500 times larger and more than 1000 times heavier than M60-UCD1,” explains Anil Seth of the University of Utah, USA, lead author of the international study. “In fact, even though the black hole at the centre of our Milky Way galaxy has the mass of 4 million Suns it is still less than 0.01 percent of the Milky Way’s total mass, which makes you realise how significant M60-UCD1’s black hole really is.”


Remembering Stellafane

  "The image is assembled from several hundred 30-second exposures made while attempting to record Perseid meteors in August 2006. The unusual-looking building in the foreground is the famous Porter Turret telescope at Stellafane. Moonlight illuminated the foreground during the exposures" - Dennis di Cicco


Remembering Stellafane

"The image is assembled from several hundred 30-second exposures made while attempting to record Perseid meteors in August 2006. The unusual-looking building in the foreground is the famous Porter Turret telescope at Stellafane. Moonlight illuminated the foreground during the exposures" - Dennis di Cicco


Milky Way above Atacama Salt Lagoon

Galaxies, stars, and a serene reflecting pool combine to create this memorable land and skyscape.

Image Credit & Copyright: Alex Tudorica (AIfA, U. Bonn)

The featured panorama is a 12-image mosaic taken last month from the Salar de Atacama salt flat in northern Chile. The calm water is Laguna Cejar, a salty lagoon featuring a large central sinkhole. On the image left, the astrophotographer’s fiancee is seen capturing the same photogenic scene.

The night sky is lit up with countless stars, the Large and Small Magellanic Cloud galaxies on the left, and the band of our Milky Way galaxy running diagonally up the right. The Milky Way may appear to be causing havoc at the horizon, but those are just the normal lights of a nearby town.


Stellar Flare Hits HD 189733b

This artist’s impression shows exoplanet HD 189733b, as it passes in front of its parent star, called HD 189733A.

Hubble’s instruments observed the system in 2010, and in 2011 following a large flare from the star (depicted in the image). Following the flare, Hubble observed the planet’s atmosphere evaporating at a rate of over 1000 tonnes per second.

In this picture, the surface of the star, which is around 80% the mass of the Sun, is based on observations of the Sun from the Solar Dynamics Observatory.


An Interacting Colossus

This picture, taken by the NASA/ESA Hubble Space Telescope’s Wide Field Planetary Camera 2 (WFPC2), shows a galaxy known as NGC 6872 in the constellation of Pavo (The Peacock).

Its unusual shape is caused by its interactions with the smaller galaxy that can be seen just above NGC 6872, called IC 4970. They both lie roughly 300 million light-years away from Earth.

From tip to tip, NGC 6872 measures over 500 000 light-years across, making it the second largest spiral galaxy discovered to date. In terms of size it is beaten only by NGC 262, a galaxy that measures a mind-boggling 1.3 million light-years in diameter!

To put that into perspective, our own galaxy, the Milky Way, measures between 100 000 and 120 000 light-years across, making NGC 6872 about five times its size.

Milky Way Madness At Mesa Arch by Mike Berenson

"Night photographer Mike Berenson provides his own "icing on the cake" in this flashlight illuminated, starry night image with Milky Way skies at Mesa Arch in Canyonlands National Park, Utah. Mike captured this image with a Nikon D800 and Bower 14mm f/2.8 Lens on August 19th, 2014."


Inspired by the cartwheeling Moroccan desert spider, the Cebrennus rechenbergi, professor Ingo Rechenberg of the Technical University of Berlin has developed a cartwheeling robot. His Tabbot — “Tabacha” means “spider” in the Berber language — mimics the agile spider’s moves. “This robot may be employed in agriculture, on the ocean floor or even on Mars,” Rechenberg said.

(via afro-dominicano)


Mapping the Light of the Cosmos

Figuring out what the structure of the universe is surprisingly hard. Most of the matter that makes up the cosmos is totally dark, and much of what is left is in tiny, dim galaxies that are virtually impossible to detect.

Image: The first image above shows one possible scenario for the distribution of light in the cosmos. Credit: Andrew Pontzen/Fabio Governato

This image shows a computer simulation of one possible scenario for the large-scale distribution of light sources in the universe. The details of how light (and hence galaxies and quasars) is distributed through the cosmos is still not a settled question – in particular, the relative contributions of (faint but numerous) galaxies and (bright but rare) quasars is unknown.

(New research from UCL cosmologists published last week shows how we should be able to find out soon.)

However, astronomers know that on the largest scales, the universe is structured as a vast web made up of filaments and clusters of galaxies, gas and dark matter separated by huge, dark voids. Observational astronomy is making strides forward in mapping out these structures in gas and light, but the smallest galaxies – less than a pixel across in the image above – might never be seen directly because they are simply too faint.

A Hubble image of a nearby faint dwarf galaxy (bottom image) shows the challenge involved in observing these objects even when they are in our galaxy’s vicinity.

These computer models are one way of trying to extrapolate from what we know to what is really there. New research from UCL now shows how we can also use future observations of gas to find out more about this elusive population of tiny galaxies.

This simulated image shows the distribution of light in an area of space over 50 million light-years across. The simulation was created by Andrew Pontzen of UCL and Fabio Governato of the University of Washington.

Solar Activity: 2010 - 2014 by Olivier Hardy


First Water Ice Clouds Found Beyond Our Solar System

For the first time, astronomers have detected water ice clouds, like the ones that shroud Earth, around a dim celestial body outside of our solar system.

Image: Astronomers have detected traces of water ice clouds in the atmosphere of the brown dwarf WISE 0855, a misfit failed star about 7.2 light-years from Earth. The discovery is the first time water ice clouds have been found beyond the solar system, scientists say Credit: Rob Gizis (CUNY BMCC) via Carnegie Institution/YouTube

Scientists discovered evidence of the alien water ice clouds in infrared images of a newly discovered brown dwarf that’s as cold as the North Pole.

"Ice clouds are predicted to be very important in the atmospheres of planets beyond our solar system, but they’ve never been observed outside of it before now," study leader Jacqueline Faherty, who is a fellow at the Carnegie Institution for Science in Washington, D.C., said in a statement.

Ice water has been found around gas giants in our solar system. NASA’s Cassini spacecraft recently detected water ice crystals on Saturn that had been churned up from deep inside the ringed planet’s thick atmosphere during a huge storm. Water ice clouds are also hidden underneath Jupiter’s stormy ammonia ice clouds.

Now, scientists found faint signatures of such clouds around the brown dwarf WISE J085510.83-071442.5, or W0855 for short. The object is the coldest brown dwarf ever observed by scientists. It lurks 7.2 light-years away from Earth and was first seen by NASA’s Wide-Field Infrared Explorer.


Lunar Maintenance by Göran Strand

The Moon is about to dock onto the lunar station Arcturus in Östersund Sweden, for some maintenance. The latest supermoon event took its toll on our only natural satellite.


Vesta’s Many Colors at Sextilia

This colorful image from NASA’s Dawn mission shows material northwest of the crater Sextilia on the giant asteroid Vesta. Sextilia, located around 30 degrees south latitude, is at the bottom right of this image.

The image was taken by Dawn’s framing camera from September to October 2011.

In this image, the entire color spectrum of Vesta becomes visible. While a large asteroid impact probably brought the black material, the red material may have been melted by the impact.

The composite image was created by assigning ratios of color information collected from several color filters in visible light and near-infrared light to maximize subtle differences in lithology (the physical characteristics of rock units, such as color, texture and composition). The color scheme pays special attention to the iron-rich mineral pyroxene.


NGC 6589-90

by Robert Gendler

This rich nebula complex is located near the center of the galaxy where dust is ubiquitous and often partially obscures the view at visible wavelengths.

The two bright blue clouds are NGC 6589 and NGC 6590. The clouds represent scattered starlight from two imbedded young blue stars. The two bright stars are part of a loose cluster known as NGC 6595. The diffuse magenta cloud is a complex HII region which absorbs the energy from the nearby bright stars and releases it in the visible red light of excited hydrogen.

The HII clouds are known as IC 1283, IC 1284 and IC 4700. This region of our galaxy is rich with dust clouds and young stars which together produce the stunning reflection nebulae we see in the image.[**]


Milky Way over Gemini Observatory by Joy Pollard

The Gemini Observatory consists of twin 8.1-meter diameter optical/infrared telescopes located on two of the best observing sites on the planet. From their locations on mountains in Hawai’i and Chile, Gemini Observatory’s telescopes can collectively access the entire sky.

Gemini is operated by a partnership of six countries including the United States, Canada, Chile, Australia, Brazil and Argentina. Any astronomer in these countries can apply for time on Gemini, which is allocated in proportion to each partner’s financial stake. [**]