Csillagászat (Hírfigyelő)

Am dat tigrope, Bordar Flip ?i solar flare

napkitores.hu - 2018. április 26. 21:15
Created by VideoShow:http://videoshowapp.com/free.

SpaceX - Fairing Final Journey - TESS 04-25-2018

napkitores.hu - 2018. április 26. 21:15
Could not take my eye off this fairing. Sorry if video is too long. Will probably never see this again. Congratulations to SpaceX for getting both fairings! This probably wont look good on...

Mysterious UFO alien ship

napkitores.hu - 2018. április 26. 21:15
This is not fake this is real.

Thanks to a Massive Release from Gaia, we now Know Where 1.7 BILLION Stars are in the Milky Way

universetoday - 2018. április 26. 20:39

On December 19th, 2013, the European Space Agency’s (ESA) Gaia spacecraft took to space with one of the most ambitious missions ever. Over the course of its planned 5-year mission (which was recently extended), this space observatory would map over a billion stars, planets, comets, asteroids and quasars in order to create the largest and most precise 3D catalog of the Milky Way ever created.

The first release of Gaia data, which took place in September 2016, contained the distances and motions of over two million stars. But the second data release, which took on April 25th, 2018, is even more impressive. Included in the release are the positions, distance indicators and motions of more than one billion stars, asteroids within our Solar System, and even stars beyond the Milky Way.

Whereas the first data release was based on just over a year’s worth of observations, the new data release covers a period of about 22 months – which ran from July 25th, 2014, to May 23rd, 2016. Preliminary analysis of this data has revealed fine details about 1.7 billion stars in the Milky Way and how they move, which is essential to understanding how our galaxy evolved over time.

ESA’s Gaia is currently on a five-year mission to map the stars of the Milky Way. Image credit: ESA/ATG medialab; background: ESO/S. Brunier.

As Günther Hasinger, the ESA Director of Science, explained in a recent ESA press release:

The observations collected by Gaia are redefining the foundations of astronomy. Gaia is an ambitious mission that relies on a huge human collaboration to make sense of a large volume of highly complex data. It demonstrates the need for long-term projects to guarantee progress in space science and technology and to implement even more daring scientific missions of the coming decades.

The precision of Gaia‘s instruments has allowed for measurements that are so accurate that it was possible to separate the parallax of stars – the apparent shift caused by the Earth’s orbit around the Sun – from their movements through the galaxy. Of the 1.7 billion stars cataloged, the parallax and velocity (aka. proper motion) of more than 1.3 billion were measured and listed.

For about 10% of these, the parallax measurements were so accurate that astronomers can directly estimate distances to the individual stars. As Anthony Brown of Leiden University, who is also the chair of the Gaia Data Processing and Analysis Consortium Executive Board, explained:

The second Gaia data release represents a huge leap forward with respect to ESAs Hipparcos satellite, Gaias predecessor and the first space mission for astrometry, which surveyed some 118 000 stars almost thirty years agoThe sheer number of stars alone, with their positions and motions, would make Gaias new catalogue already quite astonishing. But there is more: this unique scientific catalogue includes many other data types, with information about the properties of the stars and other celestial objects, making this release truly exceptional.

In addition to the proper motions of stars, the catalog provides information on a wide range of topics that will be of interest to astronomers and astrophysicists. These include brightness and color measurements of nearly all of the 1.7 billion stars cataloged, as well as information on how the brightness and color change for half a million variable stars over time.

It also contains the velocities along the line of sight of seven million stars, the surface temperatures of about 100 million, and the effect interstellar dust has on 87 million. The Gaia data also contains information on objects in our Solar System, which includes the positions of 14,000 known asteroids (which will allow for the precise determination of their orbits).

Beyond the Milky Way, Gaia obtained more accurate measurements of the positions of half a million distant quasars – bright galaxies that emit massive amounts of energy due to the presence of a supermassive black hole at their centers. In the past, quasars have been used as a reference frame for the celestial coordinates of all objects in the Gaia catalogue based on radio waves.

However, this information will now be available at optical wavelengths for the first time. This, and other developments made possible by Gaia, could revolutionize how we study our galaxy and the Universe. As Antonella Vallenari, from the Istituto Nazionale di Astrofisica (INAF), the Astronomical Observatory of Padua, Italy, and the deputy chair of the Data Processing Consortium Executive Board, indicated:

The new Gaia data are so powerful that exciting results are just jumping at us. For example, we have built the most detailed Hertzsprung-Russell diagram of stars ever made on the full sky and we can already spot some interesting trends. It feels like we are inaugurating a new era of Galactic archaeology.

The Hertzsprung-Russell diagram, which is named after the two astronomers who devised it in the early 20th century, is fundamental to the study of stellar populations and their evolution. Based on four million stars that were selected from the catalog (all of which are withing five thousand light-years from the Sun), scientist were able to reveal many fine details about stars beyond our Solar System for the first time.

Along with measurements of their velocities, the Gaia Hertzsprung-Russell diagram enables astronomers to distinguish between populations of stars that are of different ages, are located in different regions of the Milky Way (i.e. the disk and the halo), and that formed in different ways. These include fast moving stars that were previously thought to belong to the halo, but are actually part of two stellar populations.

“Gaia will greatly advance our understanding of the Universe on all cosmic scales,” said Timo Prusti, a Gaia project scientist at ESA. “Even in the neighborhood of the Sun, which is the region we thought we understood best, Gaia is revealing new and exciting features.”

For instance, for a subset of stars within a few thousand light-years of the Sun, Gaia measured their velocity in all three dimensions. From this, it has been determined that they follow a similar pattern to stars that are orbiting the galaxy at similar speeds. The cause of these patterns will be the subject of future research, as it is unclear whether its caused by our galaxy itself or are the result of interactions with smaller galaxies that merged with us in the past.

Last, but not least, Gaia data will be used to learn more about the orbits of 75 globular clusters and 12 dwarf galaxies that revolve around the Milky Way. This information will shed further light on the evolution of our galaxy, the gravitational forces affecting it, and the role played by dark matter. As Fred Jansen, the Gaia mission manager at ESA, put it:

Gaia is astronomy at its finest. Scientists will be busy with this data for many years, and we are ready to be surprised by the avalanche of discoveries that will unlock the secrets of our Galaxy.

The third release of Gaia data is scheduled to take place in late 2020, with the final catalog being published in the 2020s. Meanwhile, an extension has already been approved for the Gaia mission, which will now remain in operation until the end of 2020 (to be confirmed at the end of this year). A series of scientific papers describing what has been learned from this latest release will also appear in a special issue of Astronomy & Astrophysics.

From the evolution of stars to the evolution of our galaxy, the second Gaia data release is already proving to be a boon for astronomers and astrophysicists. Even after the mission concludes, we can expect scientists will still be analyzing the data and learning a great deal more about the structure and evolution of our Universe.

Further Reading: ESA

The post Thanks to a Massive Release from Gaia, we now Know Where 1.7 BILLION Stars are in the Milky Way appeared first on Universe Today.

14 Galaxies Might Become Universe’s Most Massive Structure

skyandtelescope.com-MostRecent - 2018. április 26. 20:21

At least 14 galaxies are swarming in the early universe, forming a protocluster with the mass of 10 trillion Suns. It might become one of the most massive structures in the universe.

The post 14 Galaxies Might Become Universe’s Most Massive Structure appeared first on Sky & Telescope.

Asteroids Smack Jupiter More Often Than Astronomers Thought

universetoday - 2018. április 26. 16:59

Pow: The July 1994 impact of Comet Shoemaker-Levy 9 on Jupiter, captured by the Hubble Space Telescope. Credit: R. Evans/J. Trauger/H. Hammel/HST Comet Science Team/NASA.

Are you keeping a eye on Jupiter? The King of the Planets, Jove presents a swirling upper atmosphere full of action, a worthy object of telescopic study as it heads towards another fine opposition on May 9th, 2018.

Now, an interesting international study out of the School of Engineering in Bilbao, Spain, the Astronomical Society of France, the Meath Astronomical Group in Dublin Ireland, the Astronomical Society of Australia, and the Esteve Duran Observatory in Spain gives us a fascinating and encouraging possibly, and another reason to keep a sharp eye on old Jove: Jupiter may just get smacked with asteroids on a more regular basis than previously thought.

The study is especially interesting, as it primarily focused in on flashes chronicled by amateur imagers and observers in recent years. In particular, researchers focused on impact events witnessed on March 17th 2016 and May 26th, 2017, along with the comparison of exogenous (of cosmic origin) dust measured in the upper atmosphere. This allowed researchers to come up with an interesting estimate: Jupiter most likely gets hit by an asteroid 5-20 meters in diameter (for comparison, the Chelyabinsk bolide was an estimated 20 meters across) 10 to 65 times every year, though researchers extrapolate that a dedicated search might only nab an impact flash or scar once every 0.4 to 2.4 years or so.

Compare this impact rate with the Earth, which gets hit by a Chelyabinsk-sized 20-meter impactor about once every half century or so. Incidentally, we know this impact rate on Earth better than ever before, largely due to U.S. Department of Defense classified assets in space continually watching for nuclear tests and missile launches, which also pick up an occasional meteor “photobomb.”

Small asteroid impacts over the span of the Earth over a 20 year period. NASA/Planetary Science.

One reason we may never have witnessed a meteor impact on Jupiter is, astronomers (both professional and amateur) never thought to look for them. The big wake-up call was the impact of Comet Shoemaker-Levy 9 in July 1994, an event witnessed by the newly refurbished Hubble Space Telescope as the resulting impact scars were easily visible in backyard telescopes for weeks afterward. Back in the day, speculation was rampant in the days leading up to the impact: would the collision be visible at all? Or would gigantic Jupiter simply gobble up the tiny comet fragments with nary a belch?

Australian amateur astronomer Anthony Wesley also caught an interesting impact (scar?) in 2009, and every few years or so, we get word of an elusive flash reported on the Jovian cloudtops, sometimes corroborated by a secondary independent observation or a resulting impact scar, and sometimes not.

An impact scar (top center on the disk) on Jupiter, captured on July 19th, 2009. Image credit: Anthony Wesley.

Of course, there are factors which will lower said ideal versus the actual observed impact rate. There’s always a month or so a year, for example, when Jupiter is near solar conjunction on the far side of the Sun, and out of range for observation. Also, we only see half of the Jovian disk from our Earthly perspective at any given time, and we’re about to lose our only set of eyes in orbit around Jupiter – NASA’s Juno spacecraft – later this summer, unless there’s a last minute mission extension.

On the plus side, however, Jupiter is a fast rotator, spinning on its axis once every 9.9 hours. This also means that near opposition, you can also track Jupiter through one full rotation in a single evening.

Finding Jupiter: looking eastward tonight at around 11PM local. Credit Stellarium.

Then there’s the planet’s location in the sky: Currently, Jupiter’s crossing the southern constellation of Libra, and opposition for Jove moves about one astronomical constellation eastward along the ecliptic a year. Jupiter will bottom out along the ecliptic in late 2019, and won’t pop back up north of the celestial equator until May 2022. And while it’s not impossible for northern observers to keep tabs on Jupiter when it’s down south, we certainly get more gaps in coverage around this time.

Hale-Bopp’s close inbound passage near Jupiter in 1996. Credit: NASA/JPL-Horizons.

Should we hail Jove as a protective ‘cosmic goal-tender,’ or fear it as the bringer of death and destruction? There are theories that Jupiter may be both: for example, Jupiter altered the inbound path of Comet Hale-Bopp in 1997, shortening its orbital period from 4,200 to 2,533 years. The 2000 book Rare Earth even included the hypothesis of Jupiter as a cosmic debris sweeper as one of the factors for why life evolved on Earth… if this is true, it’s an imperfect one, as Earth does indeed still get hit as well.

All reasons to keep an eye on Jupiter in the 2018 opposition season.

-See something strange? The ALPO Jupiter observers section wants to know!

The post Asteroids Smack Jupiter More Often Than Astronomers Thought appeared first on Universe Today.

A Yellowstone guide to life on Mars

sciencedaily.com - 2018. április 26. 01:56
A geology student is helping NASA determine whether life existed on other planets. He is helping find a marker for ancient bacterial life on Mars. The research could help scientists put to rest one of our most fundamental mysteries.

How Many Planets is TESS Going to Find?

universetoday - 2018. április 26. 01:11

The Transiting Exoplanet Survey Satellite (TESS), NASA’s latest exoplanet-hunting space telescope, was launched into space on Wednesday, April 18th, 2018. As the name suggests, this telescope will use the Transit Method to detect terrestrial-mass planets (i.e. rocky) orbiting distant stars. Alongside other next-generation telescopes like the James Webb Space Telescope (JWST), TESS will effectively pick up where telescopes like Hubble and Kepler left off.

But just how many planets is TESS expected to find? That was the subject of a new study by a team researchers who attempted to estimate just how many planets TESS is likely to discover, as well as the physical properties of these planets and the stars that they orbit. Altogether, they estimate TESS will find thousands of planets orbiting a variety of stars during its two-year primary mission.

The study, titled “A Revised Exoplanet Yield from the Transiting Exoplanet Survey Satellite (TESS)“, recently appeared online. The study was led by Thomas Barclay, an associate research scientist at the NASA Goddard Space Flight Center and the University of Maryland, and included Joshua Pepper (an astrophysicist at Lehigh University) and Elisa Quintana (a research scientist with the SETI Institute and NASA Ames Research Center).

As Thomas Barclay told Universe Today via email:

“TESS builds off the legacy of Kepler. Kepler was primarily a statistical mission and taught us that planets are everywhere. However, it wasn’t optimized for finding excellent individual planets for further study. Now that we know planets are common, we can launch something like TESS to search for the planets that we will undertake intensive studies of using ground and space-based telescopes. Planets that TESS will find will on average be 10x closer and 100x brighter.”

For the sake of their study, the team created a three-step model that took into account the stars TESS will observe, the number of planets each one is likely to have, and the likelihood of TESS spotting them. These included the kinds of planets that would be orbiting around dwarf stars ranging from A-type to K-type (like our Sun), and lower-mass M-type (red dwarf) stars.

“To estimate how many planets TESS will find we took stars that will be observed by TESS and simulated a population of planets orbiting them,” said Barclay. “The exoplanet population stats all come from studies that used Kepler data. Then, using models of TESS performance, we estimated how many of those planets would be detected by TESS. This is where we get our yield numbers from.”

The first step was straightforward, thanks to the availability of the Candidate Target List (CTL) – a prioritized list of target stars that the TESS Target Selection Working Group determined were the most suitable stars for detecting small planets. They then ranked the 3.8 million stars that are included in the latest version based on their brightness and radius and determined which of these TESS is likely to observe.

Liftoff of the SpaceX Falcon 9 rocket carrying NASA’s TESS spacecraft. Image credit: NASA TV

The second step consisted of assigning planets to each star based on a Poisson distribution, a statistical technique where a given number is assigned to each star (in this case, 0 or more). Each planet was then assigned six physical properties drawn at random, including an orbital period, a radius, an eccentricity, a periastron angle, an inclination to our line of sight, and a mid-time of first transit.

Last, they attempted to estimate how many of these planets would generate a detectable transit signal. As noted, TESS will rely on the Transit Method, where periodic dips in a star’s brightness are used to determine the presence of one or more orbiting planets, as well as place constraints on their sizes and orbital periods. For this, they considered the flux contamination of nearby stars, the number of transits, and the transit duration.

Ultimately, they determined with 90% confidence that TESS is likely to detect 4430–4660 new exoplanets during its two years mission:

“The results is that we predict that TESS will find more than 4000 planets, with hundreds smaller than twice the size of Earth. The primary goal of TESS is to find planets that are bright enough for ground-based telescope to measure their mass. We estimate that TESS could lead to triple the number of planets smaller than 4 Earth-radii with mass measurements.”

As of April 1st, 2018, a total 3,758 exoplanets have been confirmed in 2,808 systems, with 627 systems having more than one planet. In other words, Barclay and his team estimate that the TESS mission will effectively double the number of confirmed exoplanets and triple the number of Earth-sized and Super-Earth’s during its primary mission.

This will begin after a series of orbital maneuvers and engineering tests, which are expected to last for about two months. With the exoplanet catalog thus expanded, we can expect that there will be many more “Earth-like” candidates available for study. And while we still will not be able to determine if any of them have life, we may perhaps find some that show signs of a viable atmosphere and water on the surfaces.

The hunt for life beyond Earth will continue for many years to come! And in the meantime, be sure to enjoy this video about the TESS mission, courtesy of NASA:

Further Reading: Astrobites, arXiv

The post How Many Planets is TESS Going to Find? appeared first on Universe Today.

Grupo de Estudos Astronômicos de Iguaraçu – PR (GEAI)

skyandtelescope.com-MostRecent - 2018. április 25. 22:24

  NAME Grupo de Estudos Astronômicos de Iguaraçu – PR (GEAI) ADDRESS Rua: Antenor Tenente Nº 32 Bairro: Jardim Bela Vista Rua: José Ribeiro Nº 71 Bairro: Centro Iguaraçu, Paraná 86750-000 Brazil CONTACT Lucas Fiori Fiori Izaias PHONE +55 014 (44) 98436-1109 EMAIL lucasfiori120@gmail.com URL https://www.facebook.com/groups/GEAI.Astronomia NUMBER OF MEMBERS 5439 OTHER INFORMATION O Grupo de Estudos Astronômicos de Iguaraçu – PR mais conhecido como: GEAI, é um grupo de Astronomia e Ciências Afins […]

The post Grupo de Estudos Astronômicos de Iguaraçu – PR (GEAI) appeared first on Sky & Telescope.

Projectile cannon experiments show how asteroids can deliver water

sciencedaily.com - 2018. április 25. 22:20
New research shows that a surprising amount of water survives simulated asteroid impacts, a finding that may help explain how asteroids deposit water throughout the solar system.

Ultrahigh-pressure laser experiments shed light on super-Earth cores

sciencedaily.com - 2018. április 25. 22:20
Using high-powered laser beams, researchers have simulated conditions inside a planet three times as large as Earth. The pressures achieved in this study, up to 1,314 gigapascals (GPa), allowed researchers to gather the highest-pressure X-ray diffraction data ever recorded and generate new, more robust models for the interior structure of large, rocky exoplanets.

EPO10 SunSpots 2017-18

napkitores.hu - 2018. április 25. 21:15

SpaceX - First Fairings - Booster Latch - TESS 04-24-2018

napkitores.hu - 2018. április 25. 21:15
Both fairings look like they can be re-flown without doing a thing. First time both fairings recovered. Stormy weather slowed them down a bit. We are a US disabled veteran run, non-profit video...

Assembly of massive galaxy cluster witnessed for the first time

sciencedaily.com - 2018. április 25. 19:18
For the first time, astronomers have witnessed the birth of a colossal cluster of galaxies. Their observations reveal at least 14 galaxies packed into an area only four times the diameter of the Milky Way's galactic disk. Computer simulations of the galaxies predict that over time the cluster will assemble into one of the most massive structures in the modern universe.

Gaia Maps 1.7 Billion Stars, Widens Cosmic Census

skyandtelescope.com-MostRecent - 2018. április 25. 18:28

With its second data release, the European Space Agency's Gaia satellite has redefined the way we look at our galaxy.

The post Gaia Maps 1.7 Billion Stars, Widens Cosmic Census appeared first on Sky & Telescope.

Seven Nights of Enticing Lunar Sights

skyandtelescope.com-MostRecent - 2018. április 25. 18:09

Come along for a 7-night tour of some of the Moon's most compelling features visible in small telescopes.

The post Seven Nights of Enticing Lunar Sights appeared first on Sky & Telescope.

To see the first-born stars of the universe

sciencedaily.com - 2018. április 25. 18:02
ASU-led team aims to use new NASA space telescope to capture light from the first stars to be born in the universe.
Tartalom átvétel