The company Unistellar is developing a small telescope called the evScope that includes an active light amplification system that greatly brightens and sharpens images:
Turn the Amplified Vision ON and the system will start to accumulate light from the objects you are viewing all the while projecting it directly into the eyepiece of the telescope: the image is progressively intensified and in a matter of seconds colors and shapes of galaxies and nebulae, invisible in normal telescopes, will appear. Turn Field Recognition ON and the system will recognize and name the objects in the field !
Called the “eVscope” (pronounced Ee-Vee Scope) for short, Unistellar’s product outwardly appears to be just a typical 4.5-inch Newtonian reflector—a simple small telescope that, along with its tripod, easily fits inside a backpack. But a peek through its eyepiece reveals the eVscope’s power: Using a proprietary system of sensors, optics and specialized software, the telescope can amplify and display the accumulated light from a faint target over time, stacking up and processing hundreds of images to correct for instrumental jitter and smeared exposures to build up vivid, sharp views that rival those from far larger and more expensive equipment. And, as Marchis intends to show with his demonstration from a Brooklyn graveyard, the technology even works under poor viewing conditions—such as in and around New York City, where the glare of city lights is so oppressive that even on clear nights one can practically count on fingers and toes all the stars visible to the naked eye. (The technology works so well, in fact, that Unistellar’s eVscope has managed to capture and display images of faraway Pluto in its eyepiece as a dim and distant dot hanging in the light-polluted skies over Marseilles, France, and San Francisco.)
The evScope is sensitive enough for amateurs to do real science with it. The company plans to encourage citizen science projects with the device:
Through a partnership with the SETI Institute, eVscope users will have the option of automatically uploading their observations to an online database for use by amateur and professional astronomers alike. “We’ll build it up slowly, with a thousand eVscopes providing millions of frames for any given region of sky that can be combined to get good signal to noise,” Marchis says. “We could use it to search for Earth-threatening asteroids and comets, stellar occultations, supernovae, variable stars; maybe even things we can scarcely imagine—a flash of light, a laser pulse from another cosmic civilization? Who knows what we might find—it’s not like we have been observing the sky continuously at these magnitudes.”
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Unistellar plans to begin selling the evScope in 2018.
The spectacular planetary nebula NGC 7009, or the Saturn Nebula, emerges from the darkness like a series of oddly-shaped bubbles, lit up in glorious pinks and blues. This colourful image was captured by the powerful MUSE instrument on ESO’s Very Large Telescope (VLT), as part of a study which mapped the dust inside a planetary nebula for the first time. [Larger images.]The spectacular planetary nebula NGC 7009, or the Saturn Nebula, emerges from the darkness like a series of oddly-shaped bubbles, lit up in glorious pinks and blues. This colourful image was captured by the powerful MUSE instrument on ESO’s Very Large Telescope (VLT), as part of a study which mapped the dust inside a planetary nebula for the first time. The map — which reveals a wealth of intricate structures in the dust, including shells, a halo and a curious wave-like feature — will help astronomers understand how planetary nebulae develop their strange shapes and symmetries.
The spectacular planetary nebula NGC 7009, or the Saturn Nebula, emerges from the darkness like a series of oddly-shaped bubbles, lit up in glorious pinks and blues. This colourful image was captured by the powerful MUSE instrument on ESO’s Very Large Telescope (VLT), as part of a study which mapped the dust inside a planetary nebula for the first time.
The Saturn Nebula is located approximately 5000 light years away in the constellation of Aquarius (The Water Bearer). Its name derives from its odd shape, which resembles everyone’s favourite ringed planet seen edge-on.
But in fact, planetary nebulae have nothing to do with planets. The Saturn Nebula was originally a low-mass star, which expanded into a red giant at the end of its life and began to shed its outer layers. This material was blown out by strong stellar winds and energised by ultraviolet radiation from the hot stellar core left behind, creating a circumstellar nebula of dust and brightly-coloured hot gas. At the heart of the Saturn Nebula lies the doomed star, visible in this image, which is in the process of becoming a white dwarf[1].
In order to better understand how planetary nebulae are moulded into such odd shapes, an international team of astronomers led by Jeremy Walsh from ESO used the Multi Unit Spectroscopic Explorer (MUSE) to peer inside the dusty veils of the Saturn Nebula. MUSE is an instrument installed on one of the four Unit Telescopes of the Very Large Telescopeat ESO’s Paranal Observatory in Chile. It is so powerful because it doesn’t just create an image, but also gathers information about the spectrum — or range of colours — of the light from the object at each point in the image.
The spectacular planetary nebula NGC 7009, or the Saturn Nebula, emerges from the darkness like a series of oddly-shaped bubbles, lit up in glorious pinks and blues. This colourful image was captured by the powerful MUSE instrument on ESO’s Very Large Telescope (VLT), as part of a study which mapped the dust inside a planetary nebula for the first time. This annotated version labels the features of this curious object. [ Larger images.]The team used MUSE to produce the first detailed optical maps of the gas and dust distributed throughout a planetary nebula [2]. The resulting image of the Saturn Nebula reveals many intricate structures, including an elliptical inner shell, an outer shell, and a halo. It also shows two previously imaged streams extending from either end of the nebula’s long axis, ending in bright ansae (Latin for “handles”).
Intriguingly, the team also found a wave-like feature in the dust, which is not yet fully understood. Dust is distributed throughout the nebula, but there is a significant drop in the amount of dust at the rim of the inner shell, where it seems that it is being destroyed. There are several potential mechanisms for this destruction. The inner shell is essentially an expanding shock wave, so it may be smashing into the dust grains and obliterating them, or producing an extra heating effect that evaporates the dust.
Mapping the gas and dust structures within planetary nebulae will aid in understanding their role in the lives and deaths of low mass stars, and it will also help astronomers understand how planetary nebulae acquire their strange and complex shapes.
This zoom sequence starts from a very broad view of the sky and heads towards the constellation of Aquarius (The Water Bearer). After a while we see a bright tiny blue disc, which eventually turns into the spectacular planetary nebula NGC 7009, known as the Saturn Nebula because of its distinctive shape. The final image is from new data taken with the MUSE instrument on ESO’s Very Large Telescope in Chile. Credit: ESO/Digitized Sky Survey 2/N. Risinger (skysurvey.org). Music: Astral Electronic
But MUSE’s capabilities extend far beyond planetary nebulae. This sensitive instrument can also study the formation of stars and galaxies in the early Universe, as well as map the dark matter distribution in galaxy clusters in the nearby Universe. MUSE has also created the first 3D map of the Pillars of Creation in the Eagle Nebula (eso1518) and imaged a spectacular cosmic crash in a nearby galaxy (eso1437).
Notes
[1] Planetary nebulae are generally short-lived; the Saturn Nebula will last only a few tens of thousands of years before expanding and cooling to such an extent that it becomes invisible to us. The central star will then fade as it becomes a hot white dwarf.
[2] The NASA/ESA Hubble Space Telescope has previously provided a spectacular image of the Saturn Nebula — but, unlike MUSE, it cannot reveal the spectrum at each point over the whole nebula.
This artist’s impression shows the binary asteroid 288P, located in the main asteroid belt between the planets Mars and Jupiter. The object is unique as it is a binary asteroid which also behaves like a comet. The comet-like properties are the result of water sublimation, caused by the heat of the Sun. The orbit of the asteroids is marked by a blue ellipse. [Larger images]With the help of the NASA/ESA Hubble Space Telescope, a German-led group of astronomers have observed the intriguing characteristics of an unusual type of object in the asteroid belt between Mars and Jupiter: two asteroids orbiting each other and exhibiting comet-like features, including a bright coma and a long tail. This is the first known binary asteroid also classified as a comet. The research is presented in a paper published in the journal Nature this week.
In September 2016, just before the asteroid 288P made its closest approach to the Sun, it was close enough to Earth to allow astronomers a detailed look at it using the NASA/ESA Hubble Space Telescope [1].
This artist’s impression shows the binary main-belt comet 288P. From a distance the comet-like features of the system can clearly be seen: among them, the bright coma surrounding both components of the system and the long tail of dust and water pointing away from from the Sun. Only a closer look reveals the two components of the system: two asteroids circling each other on an eccentric orbit. Credit: ESA/Hubble, L. Calçada, M. Kornmesser
The images of 288P, which is located in the asteroid belt between Mars and Jupiter, revealed that it was actually not a single object, but two asteroids of almost the same mass and size, orbiting each other at a distance of about 100 kilometres. That discovery was in itself an important find; because they orbit each other, the masses of the objects in such systems can be measured.
This set of images from the ESA/NASA Hubble Space Telescope reveals two asteroids with comet-like features orbiting each other. These include a bright halo of material, called a coma, and a long tail of dust. The asteroid pair, called 288P, was observed in September 2016 just before the asteroid made its closest approach to the Sun. These images reveal ongoing activity in the binary system. The apparent movement of the tail is a projection effect due to the relative alignment between the Sun, Earth, and 288P changing between observations. The tail orientation is also affected by a change in the particle size. Initially, the tail was pointing towards the direction where comparatively large dust particles (about 1 millimetre in size) were emitted in late July. However, from 20 September 2016 onwards, the tail began to point in the opposite direction from the Sun where small particles (about 10 microns in size) are blown away from the nucleus by radiation pressure. [Larger images]But the observations also revealed ongoing activity in the binary system.
“We detected strong indications of the sublimation of water ice due to the increased solar heating — similar to how the tail of a comet is created,”
Understanding the origin and evolution of main-belt comets — asteroids orbiting between Mars and Jupiter that show comet-like activity — is a crucial element in our understanding of the formation and evolution of the whole Solar System. Among the questions main-belt comets can help to answer is how water came to Earth [2]. Since only a few objects of this type are known, 288P presents itself as an extremely important system for future studies.
This time-lapse video, assembled from a set of ESA/NASA Hubble Space Telescope images, reveals two asteroids with comet-like features orbiting each other. The asteroid pair, called 288P, was observed in September 2016, just before the asteroid made its closest approach to the Sun.
The various features of 288P — wide separation of the two components, near-equal component size, high eccentricity and comet-like activity — also make it unique among the few known wide asteroid binaries in the Solar System. The observed activity of 288P also reveals information about its past, notes Agarwal:
“Surface ice cannot survive in the asteroid belt for the age of the Solar System but can be protected for billions of years by a refractory dust mantle, only a few metres thick.”
From this, the team concluded that 288P has existed as a binary system for only about 5000 years. Agarwal elaborates on the formation scenario:
“The most probable formation scenario of 288P is a breakup due to fast rotation. After that, the two fragments may have been moved further apart by sublimation torques.”
The fact that 288P is so different from all other known binary asteroids raises some questions about whether it is not just a coincidence that it presents such unique properties. As finding 288P included a lot of luck, it is likely to remain the only example of its kind for a long time.
“We need more theoretical and observational work, as well as more objects similar to 288P, to find an answer to this question,” concludes Agarwal.
Notes
[1] Like any object orbiting the Sun, 288P travels along an elliptical path, bringing it closer and further away to the Sun during the course of one orbit.
[2] Current research indicates that water came to Earth not via comets, as long thought, but via icy asteroids.
This image depicts the two areas where most of the asteroids in the Solar System are found: the asteroid belt between Mars and Jupiter, and the trojans, two groups of asteroids moving ahead of and following Jupiter in its orbit around the Sun. The binary asteroid 288P is part of the asteroid belt. [Larger images]
This ALMA image reveals much finer structure in the U Antliae shell than has previously been possible. Around 2700 years ago, U Antliae went through a short period of rapid mass loss. During this period of only a few hundred years, the material making up the shell seen in the new ALMA data was ejected at high speed. Examination of this shell in further detail also shows some evidence of thin, wispy clouds known as filamentary substructures. [Larger images]Astronomers have used ALMA to capture a strikingly beautiful view of a delicate bubble of expelled material around the exotic red star U Antliae. These observations will help astronomers to better understand how stars evolve during the later stages of their life-cycles.
In the faint southern constellation of Antlia (The Air Pump) the careful observer with binoculars will spot a very red star, which varies slightly in brightness from week to week. This very unusual star is called U Antliae and new observations with the Atacama Large Millimeter/submillimeter Array (ALMA) are revealing a remarkably thin spherical shell around it.
Astronomers have used ALMA to capture a strikingly beautiful view of a delicate bubble of expelled material around the exotic red star U Antliae. These observations will help astronomers to better understand how stars evolve during the later stages of their life-cycles. This short podcast takes a look at this important new result and what it means. Credit: ESO.
U Antliae [1] is a carbon star, an evolved, cool and luminous star of the asymptotic giant branch type. Around 2700 years ago, U Antliae went through a short period of rapid mass loss. During this period of only a few hundred years, the material making up the shell seen in the new ALMA data was ejected at high speed. Examination of this shell in further detail also shows some evidence of thin, wispy gas clouds known as filamentary substructures.
The data collected with ALMA are not just a single image, but a three-dimensional dataset (a data cube) with each slice being observed at a slightly different wavelength. Because of the Doppler effect, different slices of the data cube show images of gas moving at different speeds towards or away from the observer. By displaying different velocities we can cut this cosmic bubble into virtual slices just as we do in computer tomography of a human body. Credit: ALMA (ESO/NAOJ/NRAO)/F. Kerschbaum
This spectacular view was only made possible by the unique ability to create sharp images at multiple wavelengths that is provided by the ALMA radio telescope, located on the Chajnantor Plateau in Chile’s Atacama Desert. ALMA can see much finer structure in the U Antliae shell than has previously been possible.
This video sequence takes the viewer on an imaginary journey from Earth to the red and ageing star U Antliae. Near the start we see the Moon briefly and later we pass many stars that are closer to Earth than the final goal of the journey, a rare carbon star about 900 light-years away. Credit: ESO/spaceengine.org
The new ALMA data are not just a single image; ALMA produces a three-dimensional dataset (a data cube) with each slice being observed at a slightly different wavelength. Because of the Doppler Effect, this means that different slices of the data cube show images of gas moving at different speeds towards or away from the observer. This shell is also remarkable as it is very symmetrically round and also remarkably thin. By displaying the different velocities we can cut this cosmic bubble into virtual slices just as we do in computer tomography of a human body.
This image was created from ALMA data on the unusual red carbon star U Antliae and its surrounding shell of material. The colours show the motion of the glowing material in the shell along the line of sight to the Earth. Blue material lies between us and the central star, and is moving towards us. Red material around the edge is moving away from the star, but not towards the Earth. For clarity this view does not include the material on the far side of the star, which is receding from us in a symmetrical manner. [Large image.]Understanding the chemical composition of the shells and atmospheres of these stars, and how these shells form by mass loss, is important to properly understand how stars evolve in the early Universe and also how galaxies evolved. Shells such as the one around U Antliae show a rich variety of chemical compounds based on carbon and other elements. They also help to recycle matter, and contribute up to 70% of the dust between stars.
Notes [1] The name U Antliae reflects the fact that it is the fourth star that changes its brightness to be found in the constellation of Antlia (The Air Pump). The naming of such variable stars followed a complicated sequence as more and more were found and is explained here.
This image from the Digitized Sky Survey 2 shows the very red carbon star U Antliae and its surroundings. [ Larger Images.]
This artist’s impression shows the exoplanet WASP-12b — an alien world as black as fresh asphalt, orbiting a star like our Sun. Scientists were able to measure its albedo: the amount of light the planet reflects. The results showed that the planet is extremely dark at optical wavelengths. [Larger image]
Astronomers have discovered that the well-studied exoplanet WASP-12b reflects almost no light, making it appear essentially pitch black. This discovery sheds new light on the atmospheric composition of the planet and also refutes previous hypotheses about WASP-12b’s atmosphere. The results are also in stark contrast to observations of another similarly sized exoplanet.
Using the Space Telescope Imaging Spectrograph (STIS) on the NASA/ESA Hubble Space Telescope, an international team led by astronomers at McGill University, Canada, and the University of Exeter, UK, have measured how much light the exoplanet WASP-12b reflects — its albedo — in order to learn more about the composition of its atmosphere [1].
The results were surprising, explains lead author Taylor Bell, a Master’s student in astronomy at McGill University who is affiliated with the Institute for Research on Exoplanets:
“The measured albedo of WASP-12b is 0.064 at most. This is an extremely low value, making the planet darker than fresh asphalt!”
This makes WASP-12b two times less reflective than our Moon which has an albedo of 0.12 [2]. Bell adds:
“The low albedo shows we still have a lot to learn about WASP-12b and other similar exoplanets.”
WASP-12b orbits the Sun-like star WASP-12A, about 1400 light-years away, and since its discovery in 2008 it has become one of the best studied exoplanets (opo1354, opo1015, opo1436, heic1524). With a radius almost twice that of Jupiter and a year of just over one Earth day, WASP-12b is categorised as a hot Jupiter. Because it is so close to its parent star, the gravitational pull of the star has stretched WASP-12b into an egg shape and raised the surface temperature of its daylight side to 2600 degrees Celsius.
The high temperature is also the most likely explanation for WASP-12b’s low albedo.
“There are other hot Jupiters that have been found to be remarkably black, but they are much cooler than WASP-12b. For those planets, it is suggested that things like clouds and alkali metals are the reason for the absorption of light, but those don’t work for WASP-12b because it is so incredibly hot,” explains Bell.
The daylight side of WASP-12b is so hot that clouds cannot form and alkali metals are ionised. It is even hot enough to break up hydrogen molecules into atomic hydrogen which causes the atmosphere to act more like the atmosphere of a low-mass star than like a planetary atmosphere. This leads to the low albedo of the exoplanet.
To measure the albedo of WASP-12b the scientists observed the exoplanet in October 2016 during an eclipse, when the planet was near full phase and passed behind its host star for a time. This is the best method to determine the albedo of an exoplanet, as it involves directly measuring the amount of light being reflected. However, this technique requires a precision ten times greater than traditional transit observations. Using Hubble’s Space Telescope Imaging Spectrograph the scientists were able to measure the albedo of WASP-12b at several different wavelengths.
“After we measured the albedo we compared it to spectral models of previously suggested atmospheric models of WASP-12b”, explains Nikolay Nikolov (University of Exeter, UK), co-author of the study. “We found that the data match neither of the two currently proposed models.”[3].
The new data indicate that the WASP-12b atmosphere is composed of atomic hydrogen and helium.
WASP-12b is only the second planet to have spectrally resolved albedo measurements, the first being HD 189733b, another hot Jupiter. The data gathered by Bell and his team allowed them to determine whether the planet reflects more light towards the blue or the red end of the spectrum. While the results for HD 189733b suggest that the exoplanet has a deep blue colour (heic1312), WASP-12b, on the other hand, is not reflecting light at any wavelength. WASP-12b does, however, emit light because of its high temperature, giving it a red hue similar to a hot glowing metal.
“The fact that the first two exoplanets with measured spectral albedo exhibit significant differences demonstrates the importance of these types of spectral observations and highlights the great diversity among hot Jupiters,” concludes Bell.
Notes
[1] The team measured the optical geometric albedo of WASP-12b, which measures the light that is scattered back towards the source of light, and can have values above 1. This is in contrast to the Bond albedo, which describes the total amount of energy reflected across all wavelengths and always falls in the range of 0 to 1.
[2] Earth has an average optical geometric albedo of about 0.37. Enceladus, an icy moon of Saturn, has an albedo of 1.4, the highest known albedo of any celestial body in the Solar System.
[3] One proposed model was an aluminum-oxide atmosphere with Mie scattering while the other was a cloud-free atmosphere with Rayleigh scattering.
