Author Topic: ESA - Gaia updates  (Read 123672 times)

Online jacqmans

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Re: ESA - Gaia updates
« Reply #60 on: 09/01/2016 01:04 pm »
Press Release
N°29-2016

Paris, 1 September 2016

Call for media: First data release from ESA's Gaia mission 

Media representatives are invited to a briefing on the first data release of ESA's Gaia mission, an astrometry mission to map the stars of our galaxy, the Milky Way.

The media briefing is being organised by ESA at the European Space Astronomy Centre (ESAC) in Villanueva de la Cañada, Madrid, Spain, on Wednesday 14 September 2016, 11:30-13:00 CEST. Doors open at 11:00 CEST. 

Launched in December 2013, Gaia is destined to create the most accurate map yet of the Milky Way. By making accurate measurements of the positions and motions of stars in the Milky Way, it will answer questions about the origin and evolution of our
home galaxy.

The first data release, containing among other things three-dimensional positions and two-dimensional motions of a subset of two million stars, demonstrates that Gaia's measurements are as precise as planned, paving the way to create the full map of
one billion stars to be released towards the end of 2017. 

The media briefing will provide examples of the performance of the satellite and its science data and will highlight the science that can be done with this first data release.


Programme outline

11:30-11:40 - 
Alvaro Gimenez, Director of Science, ESA:
Astrometry with Gaia at the very core of ESA's Science Programme 

11:40-11:50 - 
Fred Jansen, ESA Gaia Mission Manager:
Operating at the limits of precision 

11:50-12:00 - 
Timo Prusti, ESA Gaia Project Scientist:
Gaia on the way to the most precise map of our galaxy 

12:00-12:10 - 
Anthony Brown, Gaia Data Processing and Analysis Consortium, Leiden University:
A first exploration of the Gaia sky

12:10-12:20- 
Antonella Vallenari, Gaia Data Processing and Analysis Consortium, Instituto Nazionale di Astrofisica (INAF), Astronomical Observatory of Padua:
Gaia's view of the nearby star clusters

12:20-12:30 - 
Gisella Clementini, Gaia Data Processing and Analysis Consortium Member of Coordination Unit 7, Instituto Nazionale di Astrofisica (INAF), Astronomical Observatory of Bologna:
Gaia and the distance ladder   

12:30-13:00 - 
Question and Answer sessions and opportunity for individual interviews

Accreditation

For accreditation, media can register at: [email protected]
Please register by 12 September.

How to get to ESAC: http://www.esa.int/About_Us/ESAC/Getting_to_ESAC

Follow online

Webstreaming

www.youtube/esa

Social media

Twitter: @esascience. Ask questions via #AskESA.
Jacques :-)

Offline denis

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Re: ESA - Gaia updates
« Reply #61 on: 09/02/2016 07:59 pm »
Information and statistics on the first data release:

http://www.cosmos.esa.int/web/gaia/dr1

Link to the Gaia data archive (real data only from the 14 of Septembre):
http://gea.esac.esa.int/archive/


Image credit: ESA/Gaia/DPAC.
« Last Edit: 09/02/2016 08:10 pm by denis »

Offline zubenelgenubi

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Re: ESA - Gaia updates
« Reply #62 on: 09/02/2016 11:29 pm »
Information and statistics on the first data release:
re: graph
Wow!

I'm still disappointed FAME (Full-sky Astrometric Mapping Explorer) was cancelled and that USNO didn't get to fly their mission--old news.

And, we had to wait for so long after Hipparcos for the next astrometry mission.

Looking forward to September 14!
« Last Edit: 09/02/2016 11:30 pm by zubenelgenubi »
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Offline Nilof

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Re: ESA - Gaia updates
« Reply #63 on: 09/03/2016 01:40 am »
I'm interested in the real meat - what is the distance to the Pleiades star cluster? Were the Hipparcos parallax measurements indeed wrong?
For a variable Isp spacecraft running at constant power and constant acceleration, the mass ratio is linear in delta-v.   Δv = ve0(MR-1). Or equivalently: Δv = vef PMF. Also, this is energy-optimal for a fixed delta-v and mass ratio.

Offline JulesVerneATV

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Re: ESA - Gaia updates
« Reply #64 on: 09/03/2016 05:39 pm »
Call for media: First data release from ESA's Gaia mission
http://www.satprnews.com/2016/09/01/call-for-media-first-data-release-from-esas-gaia-mission/
Media representatives are invited to a briefing on the first data release of ESA’s Gaia mission, an astrometry mission to map the stars of our galaxy, the Milky Way

 Two years' worth of data from the European Space Agency's (ESA) Gaia spacecraft – which includes a camera with a billion pixels – is scheduled for public release on 14 September.

Gaia will give the most detailed map of the universe ever undertaken. The spacecraft, which has a camera comprised of a mosaic of 106 CCDs, is designed to pinpoint the positions, distances, motions and other properties of more than a billion stars.

It has three instruments collecting astrometric, photometric and spectroscopic data on stars in the Milky Way galaxy, as well as more distant galaxies and quasars, and nearby, but faint Solar System objects.

Located at the L2 Lagrange point, 1.5 million kilometres from Earth, Gaia surveys the entire sky as it spins on its axis. By repeatedly measuring the positions of the stars, Gaia is providing data that enables scientists to calculate their distances and motions through our Galaxy.

‘More than 50 billion focal plane transits, 110 billion photometric observations and 9.4 billion spectroscopic observations have been successfully processed to date,’ noted Fred Jansen, ESA's mission manager for Gaia.

Question and Answer Sessions and opportunity for individual interviews

Offline bolun

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Re: ESA - Gaia updates
« Reply #65 on: 09/12/2016 02:16 pm »
Watch Gaia first data release media briefing

Livestreaming of the media briefing on the first data release from ESA’s Gaia mission will begin on 14 September at 09:30 GMT (11:30 CEST).

The media briefing will provide examples of the performance of the satellite and its science data, and will highlight the research that can be done with this first data release.



Social-media updates will be provided on Twitter: @esascience. Ask questions via #AskESA.

Last update: 12 September 2016

http://www.esa.int/Our_Activities/Space_Science/Gaia/Watch_Gaia_first_data_release_media_briefing
« Last Edit: 09/12/2016 02:22 pm by bolun »

Offline bolun

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Re: ESA - Gaia updates
« Reply #66 on: 09/12/2016 08:37 pm »
ESA’s Star Mapper visualisation

In 1989, ESA launched the first space mission dedicated to astrometry – the science of charting the sky. The satellite was named Hipparcos, echoing the name of ancient Greek astronomer, Hipparchus, who compiled the oldest known stellar catalogue in the second century BC.

Hipparcos operated for over three years and a catalogue based on its data, released in 1997, had a major impact on many areas of astronomy research.

This catalogue listed 117 955 stars, reporting their positions with unprecedented accuracy, alongside estimates of their distance from us and motions through the Galaxy. It was a huge advance on the best catalogues compiled from ground-based observations, which contained information for just over 8000 stars.

The newly launched ESA Star Mapper visualisation is an exploration of some central aspects of astrometric star catalogues, using data from ESA’s Hipparcos mission.

This interactive experience allows users to delve into this famous dataset, exploring the three-dimensional distribution of almost 60 000 stars from the Hipparcos Catalogue. Stars are visualised as a function of their brightness; it is also possible to show their colours, as well as names and parent constellations for the brightest stars.

Users can get a sense of where in the sky stars were located in the past – or will be in the future – based on their motions measured by Hipparcos.

A visualisation of the ‘Hertzsprung-Russell diagram’, a tool used by astronomers to study the evolution of stars, is provided as well.

The next great breakthrough in this field will come with ESA’s Gaia mission, launched in 2013. Gaia will make a census of more than a billion stars – roughly 1% of the content of our Galaxy – of such superb precision and detail that it will revolutionise astronomy again.

The journey starts at: http://sci.esa.int/star_mapper/

More about Hipparcos: http://sci.esa.int/hipparcos/

http://www.esa.int/spaceinimages/Images/2016/09/ESA_s_Star_Mapper_visualisation

Image credit: ESA

Offline as58

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Re: ESA - Gaia updates
« Reply #67 on: 09/14/2016 10:57 am »
I'm interested in the real meat - what is the distance to the Pleiades star cluster? Were the Hipparcos parallax measurements indeed wrong?

If I understood correctly, new Gaia estimate disagrees with Hipparcos and agrees with the other estimates.

Offline Star One

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Re: ESA - Gaia updates
« Reply #68 on: 09/14/2016 11:33 am »

GAIA'S BILLION-STAR MAP HINTS AT TREASURES TO COME

13 September 2016
The first catalogue of more than a billion stars from ESA's Gaia satellite was published today – the largest all-sky survey of celestial objects to date.
 
Gaia's first sky map. Credit: ESA/Gaia/DPAC. Acknowledgement: A. Moitinho & M. Barros (CENTRA – University of Lisbon), F. Mignard (Observatoire de la Côte d'Azur), on behalf of DPAC.
On its way to assembling the most detailed 3D map ever made of our Milky Way galaxy, Gaia has pinned down the precise position on the sky and the brightness of 1142 million stars.
As a taster of the richer catalogue to come in the near future, today's release also features the distances and the motions across the sky for more than two million stars.

Gaia's first sky map, annotated.
"Gaia is at the forefront of astrometry, charting the sky at precisions that have never been achieved before," says Alvaro Giménez, ESA's Director of Science.
"Today's release gives us a first impression of the extraordinary data that await us and that will revolutionise our understanding of how stars are distributed and move across our Galaxy."
Launched 1000 days ago, Gaia started its scientific work in July 2014. This first release is based on data collected during its first 14 months of scanning the sky, up to September 2015.
"The beautiful map we are publishing today shows the density of stars measured by Gaia across the entire sky, and confirms that it collected superb data during its first year of operations," says Timo Prusti, Gaia project scientist at ESA.
The stripes and other artefacts in the image reflect how Gaia scans the sky, and will gradually fade as more scans are made during the five-year mission.

Gaia scanning the sky. Click here for details and large versions of the video. Credit: ESA/Gaia/DPAC. Acknowledgement: B. Holl (University of Geneva, Switzerland), A. Moitinho & M. Barros (CENTRA – University of Lisbon), on behalf of DPAC.
"The satellite is working well and we have demonstrated that it is possible to handle the analysis of a billion stars. Although the current data are preliminary, we wanted to make them available for the astronomical community to use as soon as possible," adds Dr Prusti.
Transforming the raw information into useful and reliable stellar positions to a level of accuracy never possible before is an extremely complex procedure, entrusted to a pan-European collaboration of about 450 scientists and software engineers: the Gaia Data Processing and Analysis Consortium, or DPAC.
"Today's release is the result of a painstaking collaborative work over the past decade," says Anthony Brown from Leiden University in the Netherlands, and consortium chair.
"Together with experts from a variety of disciplines, we had to prepare ourselves even before the start of observations, then treated the data, packaged them into meaningful astronomical products, and validated their scientific content."
In addition to processing the full billion-star catalogue, the scientists looked in detail at the roughly two million stars in common between Gaia's first year and the earlier Hipparcos and Tycho-2 Catalogues, both derived from ESA's Hipparcos mission, which charted the sky more than two decades ago.
By combining Gaia data with information from these less precise catalogues, it was possible to start disentangling the effects of 'parallax' and 'proper motion' even from the first year of observations only. Parallax is a small motion in the apparent position of a star caused by Earth's yearly revolution around the Sun and depends on a star's distance from us, while proper motion is due to the physical movement of stars through the Galaxy.
In this way, the scientists were able to estimate distances and motions for the two million stars spread across the sky in the combined Tycho–Gaia Astrometric Solution, or TGAS.
This new catalogue is twice as precise and contains almost 20 times as many stars as the previous definitive reference for astrometry, the Hipparcos Catalogue.
As part of their work in validating the catalogue, DPAC scientists have conducted a study of open stellar clusters – groups of relatively young stars that were born together – that clearly demonstrates the improvement enabled by the new data.

From the Solar System to the Hyades cluster. Click here for details and large versions of the video. Credit: ESA/Gaia/DPAC. Acknowledgement: T. Sagristà Sellés & S. Jordan (Zentrum für Astronomie der Universität Heidelberg)
"With Hipparcos, we could only analyse the 3D structure and dynamics of stars in the Hyades, the nearest open cluster to the Sun, and measure distances for about 80 clusters up to 1600 light-years from us," says Antonella Vallenari from the Istituto Nazionale di Astrofisica (INAF) and the Astronomical Observatory of Padua, Italy.
"But with Gaia's first data, it is now possible to measure the distances and motions of stars in about 400 clusters up to 4800 light-years away.
"For the closest 14 open clusters, the new data reveal many stars surprisingly far from the centre of the parent cluster, likely escaping to populate other regions of the Galaxy."
Many more stellar clusters will be discovered and analysed in even greater detail with the extraordinary data that Gaia continues to collect and that will be released in the coming years.
The new stellar census also contains 3194 variable stars, stars that rhythmically swell and shrink in size, leading to periodic brightness changes.
Many of the variables seen by Gaia are in the Large Magellanic Cloud, one of our galactic neighbours, a region that was scanned repeatedly during the first month of observations, allowing accurate measurement of their changing brightness.
Details about the brightness variations of these stars, 386 of which are new discoveries, are published as part of today's release, along with a first study to test the potential of the data.
"Variable stars like Cepheids and RR Lyraes are valuable indicators of cosmic distances," explains Gisella Clementini from INAF and the Astronomical Observatory of Bologna, Italy.
"While parallax is used to measure distances to large samples of stars in the Milky Way directly, variable stars provide an indirect, but crucial step on our 'cosmic distance ladder', allowing us to extend it to faraway galaxies."
This is possible because some kinds of variable stars are special. For example, in the case of Cepheid stars, the brighter they are intrinsically, the slower their brightness variations. The same is true for RR Lyraes when observed in infrared light. The variability pattern is easy to measure and can be combined with the apparent brightness of a star to infer its true brightness.
This is where Gaia steps in: in the future, scientists will be able to determine very accurate distances to a large sample of variable stars via Gaia's measurements of parallaxes. With those, they will calibrate and improve the relation between the period and brightness of these stars, and apply it to measure distances beyond our Galaxy. A preliminary application of data from the TGAS looks very promising.
"This is only the beginning: we measured the distance to the Large Magellanic Cloud to test the quality of the data, and we got a sneak preview of the dramatic improvements that Gaia will soon bring to our understanding of cosmic distances," adds Dr Clementini.
Knowing the positions and motions of stars in the sky to astonishing precision is a fundamental part of studying the properties and past history of the Milky Way and to measure distances to stars and galaxies, but also has a variety of applications closer to home – for example, in the Solar System.

Pluto occultation. Credit: B. Sicardy (LESIA, Observatoire de Paris, France), P. Tanga (Observatoire de la Côte d'Azur, Nice, France), A. Carbognani (Osservatorio Astronomico Valle d'Aosta, Italy), Rodrigo Leiva (LESIA, Observatoire de Paris)
In July, Pluto passed in front of a distant, faint star, offering a rare chance to study the atmosphere of the dwarf planet as the star gradually disappeared and then reappeared behind Pluto.
This stellar occultation was visible only from a narrow strip stretching across Europe, similar to the totality path that a solar eclipse lays down on our planet's surface. Precise knowledge of the star's position was crucial to point telescopes on Earth, so the exceptional early release of the Gaia position for this star, which was 10 times more precise than previously available, was instrumental to the successful monitoring of this rare event.
Early results hint at a pause in the puzzling pressure rise of Pluto's tenuous atmosphere, something that has been recorded since 1988 in spite of the dwarf planet moving away from the Sun, which would suggest a drop in pressure due to cooling of the atmosphere.
"These three examples demonstrate how Gaia's present and future data will revolutionise all areas of astronomy, allowing us to investigate our place in the Universe, from our local neighbourhood, the Solar System, to Galactic and even grander, cosmological scales," explains Dr Brown.
This first data release shows that the mission is on track to achieve its ultimate goal: charting the positions, distances, and motions of one billion stars – about 1% of the Milky Way's stellar content – in three dimensions to unprecedented accuracy.
"The road to today has not been without obstacles: Gaia encountered a number of technical challenges and it has taken an extensive collaborative effort to learn how to deal with them," says Fred Jansen, Gaia mission manager at ESA.
"But now, 1000 days after launch and thanks to the great work of everyone involved, we are thrilled to present this first dataset and are looking forward to the next release, which will unleash Gaia's potential to explore our Galaxy as we've never seen it before."
NOTES FOR EDITORS
The data from Gaia's first release can be accessed at http://archives.esac.esa.int/gaia
The content of this first release was presented today during a media briefing at ESA's European Space Astronomy Centre (ESAC) in Villanueva de la Cañada, Madrid, Spain.
Fifteen scientific papers describing the data contained in the release and their validation process will appear in a special issue of Astronomy & Astrophysics.
Gaia is an ESA mission to survey one billion stars in our Galaxy and local galactic neighbourhood in order to build the most precise 3D map of the Milky Way and answer questions about its structure, origin and evolution.
A large pan-European team of expert scientists and software developers, the Data Processing and Analysis Consortium, located in and funded by many ESA member states, is responsible for the processing and validation of Gaia's data, with the final objective of producing the Gaia Catalogue. Scientific exploitation of the data will only take place once they are openly released to the community.
Members of the consortium come from 20 European countries (Austria, Belgium, Czech Republic, Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Ireland, Italy, Netherlands, Poland, Portugal, Slovenia, Spain, Switzerland, Sweden and the UK) as well as from further afield (Algeria, Brazil, Israel and the US).
In addition, ESA makes a significant contribution to the consortium in the form of the Data Processing Centre at ESAC, which, among other tasks and responsibilities, acts as the central hub for all Gaia data processing.
FOR FURTHER INFORMATION, PLEASE CONTACT:
Markus Bauer
ESA Science and Robotic Exploration Communication Officer
Tel: +31 71 565 6799
Mob: +31 61 594 3 954
Email: [email protected]
Timo Prusti
Gaia Project Scientist
European Space Agency
Email: [email protected]
Anthony Brown
Leiden Observatory, Leiden University
Leiden, The Netherlands
Email: [email protected]
Antonella Vallenari
INAF and Astronomical Observatory of Padua, Italy
Email: [email protected]
Gisella Clementini
INAF and Astronomical Observatory of Bologna, Italy
Email: [email protected]
Fred Jansen
Gaia mission manager
European Space Agency
Email: [email protected]

Last Update: 14 September 2016

Offline bolun

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Re: ESA - Gaia updates
« Reply #69 on: 09/14/2016 08:35 pm »
Gaia's first sky map, annotated

An all-sky view of stars in our Galaxy – the Milky Way – and neighbouring galaxies, based on the first year of observations from ESA's Gaia satellite, from July 2014 to September 2015.

This map shows the density of stars observed by Gaia in each portion of the sky. Brighter regions indicate denser concentrations of stars, while darker regions correspond to patches of the sky where fewer stars are observed.

The Milky Way is a spiral galaxy, with most of its stars residing in a disc about 100 000 light-years across and about 1000 light-years thick. This structure is visible in the sky as the Galactic Plane – the brightest portion of this image –which runs horizontally and is especially bright at the centre.

Darker regions across the Galactic Plane correspond to dense clouds of interstellar gas and dust that absorb starlight along the line of sight.

Many globular and open clusters – groupings of stars held together by their mutual gravity – are also sprinkled across the image.

Globular clusters, large assemblies of hundreds of thousands to millions of old stars, are mainly found in the halo of the Milky Way, a roughly spherical structure with a radius of about 100 000 light-years, and so are visible across the image.
Open clusters are smaller assemblies of hundreds to thousands of stars and are found mainly in the Galactic Plane.

The two bright objects in the lower right of the image are the Large and Small Magellanic Clouds, two dwarf galaxies orbiting the Milky Way. Other nearby galaxies are also visible, most notably Andromeda (also known as M31), the largest galactic neighbour to the Milky Way, in the lower left of the image. Below Andromeda is its satellite, the Triangulum galaxy (M33).

A number of artefacts are also visible on the image. These curved features and darker stripes are not of astronomical origin but rather reflect Gaia's scanning procedure. As this map is based on observations performed during the mission's first year, the survey is not yet uniform across the sky.

These artefacts will gradually disappear as more data are gathered during the five-year mission.

High resolution versions of the Gaia map, without annotation and with a transparent background, are available to download from: http://sci.esa.int/gaia/58209

http://sci.esa.int/gaia/58281-gaia-s-first-sky-map-annotated/

Image credit: ESA/Gaia/DPAC

Acknowledgement: A. Moitinho & M. Barros (CENTRA – University of Lisbon), on behalf of DPAC

Offline jgoldader

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Re: ESA - Gaia updates
« Reply #70 on: 09/14/2016 10:39 pm »
Looks like a nice data set.  I was hoping they'd show a color-magnitude diagram or two, but the Cepheid & RR Lyrae P-L plots were nice.  I bet there's quite a race on right now by different groups to get the first papers on arXiv.
Recovering astronomer

Offline denis

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Re: ESA - Gaia updates
« Reply #71 on: 09/15/2016 12:01 am »
Looks like a nice data set.  I was hoping they'd show a color-magnitude diagram or two, but the Cepheid & RR Lyrae P-L plots were nice.  I bet there's quite a race on right now by different groups to get the first papers on arXiv.

You mean a H-R diagram ? I think they showed one during the press conference but haven't seen it on the website

Offline Mongo62

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Re: ESA - Gaia updates
« Reply #72 on: 09/15/2016 12:24 am »
Looks like a nice data set.  I was hoping they'd show a color-magnitude diagram or two, but the Cepheid & RR Lyrae P-L plots were nice.  I bet there's quite a race on right now by different groups to get the first papers on arXiv.

This didn't take long...

Accurate, Empirical Radii and Masses of Planets with Gaia Parallaxes

We present new, empirical measurements of the radii of 132 stars that host transiting planets. These stellar radii are determined using only direct observables---the bolometric flux at Earth, the stellar effective temperature, and the parallax newly provided by the Gaia first data release---and thus are virtually model independent, extinction being the only free parameter. We also determine each star's mass using our newly determined radius and the stellar density, itself a virtually model independent quantity from the previously published transit analysis. The newly determined stellar radii and masses are in turn used to re-determine the transiting planet radii and masses, once again using only direct observables. The uncertainties on the stellar radii and masses are typically 7% and 25%, respectively, and the resulting uncertainties on the planet radii and masses are 8% and 20%, respectively. These accuracies are generally larger than the previously published model-dependent precisions of 5% and 6% on the planet radii and masses, respectively, but the newly determined values are purely empirical. We additionally report stellar radii for 366 stars that host radial-velocity (non-transiting) planets, with a typical achieved accuracy in the radii of 3%. Most importantly, the stellar bolometric fluxes and angular radii reported here---with typical accuracies of 2% and 3%, respectively---will serve as a fundamental data set to permit the re-determination of the planet radii and masses with the Gaia second data release to 3% and 7% accuracy, comparable to or better than currently published precisions, but in an entirely empirical fashion.

Offline Galactic Penguin SST

Re: ESA - Gaia updates
« Reply #73 on: 09/15/2016 01:37 am »
Is there any place where the figures are presented in an easy to view format (distance in light years, star type etc.)? I have been waiting for this day to re-ignite my interest in star population census.  ;) (e.g. Can Eta Carinae keep the title of one of the galaxy's most bright stars?)
Astronomy & spaceflight geek penguin. In a relationship w/ Space Shuttle Discovery. Current Priority: Chasing the Chinese Spaceflight Wonder Egg & A Certain Chinese Mars Rover

Offline CuddlyRocket

Re: ESA - Gaia updates
« Reply #74 on: 09/15/2016 04:30 am »
Is there any place where the figures are presented in an easy to view format (distance in light years, star type etc.)?

You'll be lucky! Although ESA is playing lip-service to the idea of public engagement and for members of the public to search the database to find items of interest, they don't appear to have actually done anything to facilitate same.

There is a search page, the use of which is presumably self-evident to professional astronomers etc, but which is far from clear to me, and possibly most laymen. There's no how-to-use guide available, for instance. Or at least I couldn't find one! Given BBC news showed some schoolchildren who found a supernova, it's presumably not that difficult to use once you know how. Was there some material given to teachers by ESA, or did this school just happen to have contact with somehow who's familiar with such database search engines? A local university outreach perhaps?

This follows the frankly dire media presentation. ESA is notoriously poor at public outreach compared to NASA; this could be down to budgets, but I suspect it's because the individuals involved don't care that much.

Offline Stan-1967

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Re: ESA - Gaia updates
« Reply #75 on: 09/15/2016 04:53 am »
Is there any place where the figures are presented in an easy to view format (distance in light years, star type etc.)?

You'll be lucky! Although ESA is playing lip-service to the idea of public engagement and for members of the public to search the database to find items of interest, they don't appear to have actually done anything to facilitate same.

There is a search page, the use of which is presumably self-evident to professional astronomers etc, but which is far from clear to me, and possibly most laymen. There's no how-to-use guide available, for instance. Or at least I couldn't find one! Given BBC news showed some schoolchildren who found a supernova, it's presumably not that difficult to use once you know how. Was there some material given to teachers by ESA, or did this school just happen to have contact with somehow who's familiar with such database search engines? A local university outreach perhaps?

This follows the frankly dire media presentation. ESA is notoriously poor at public outreach compared to NASA; this could be down to budgets, but I suspect it's because the individuals involved don't care that much.

You can use the search feature using identifiers from the Kepler Input Catalog.   I suspect it also works with the Hipparcos catalog.   You should find a column listing the parallax in milliarc seconds.  You have to convert that to parsec or light years.   I tried it for KIC 8462852, but couldn't get my conversion to match what was on reddit.  It's definately not friendly.  Par for the course when dealing with ESA.

Offline Star One

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Re: ESA - Gaia updates
« Reply #76 on: 09/15/2016 05:57 am »
Is there any place where the figures are presented in an easy to view format (distance in light years, star type etc.)?

You'll be lucky! Although ESA is playing lip-service to the idea of public engagement and for members of the public to search the database to find items of interest, they don't appear to have actually done anything to facilitate same.

There is a search page, the use of which is presumably self-evident to professional astronomers etc, but which is far from clear to me, and possibly most laymen. There's no how-to-use guide available, for instance. Or at least I couldn't find one! Given BBC news showed some schoolchildren who found a supernova, it's presumably not that difficult to use once you know how. Was there some material given to teachers by ESA, or did this school just happen to have contact with somehow who's familiar with such database search engines? A local university outreach perhaps?

This follows the frankly dire media presentation. ESA is notoriously poor at public outreach compared to NASA; this could be down to budgets, but I suspect it's because the individuals involved don't care that much.

You can use the search feature using identifiers from the Kepler Input Catalog.   I suspect it also works with the Hipparcos catalog.   You should find a column listing the parallax in milliarc seconds.  You have to convert that to parsec or light years.   I tried it for KIC 8462852, but couldn't get my conversion to match what was on reddit.  It's definately not friendly.  Par for the course when dealing with ESA.

Look on the Twitter feed of Jason Wright for conversion to light years for that particular star.

Offline as58

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Re: ESA - Gaia updates
« Reply #77 on: 09/15/2016 07:08 am »
You can use the search feature using identifiers from the Kepler Input Catalog.   I suspect it also works with the Hipparcos catalog.   You should find a column listing the parallax in milliarc seconds.  You have to convert that to parsec or light years.   I tried it for KIC 8462852, but couldn't get my conversion to match what was on reddit.  It's definately not friendly.  Par for the course when dealing with ESA.

Distance in parsecs is just 1 divided by parallax in arcseconds, so dividing one by the parallax in milliarcseconds gives distance in kiloparsecs (This is actually pretty much the definition of parsec. Even the name comes from parallax second). To get the distance in lightyears, multiply the distance in parsecs by about 3.26.

The search works with pretty much any name for a star (various catalogue numbers, Bayer designation, proper name etc.). Note however that there is no data for the brightest stars, so there are not many (any?) stars with a proper name included. The search will still resolve the name, but there is no data returned.
« Last Edit: 09/15/2016 10:04 am by as58 »

Offline Star One

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Re: ESA - Gaia updates
« Reply #78 on: 09/15/2016 07:55 am »
Are systematic errors those errors introduced into the results by Gaia itself?

Offline as58

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Re: ESA - Gaia updates
« Reply #79 on: 09/15/2016 08:30 am »
Are systematic errors those errors introduced into the results by Gaia itself?

No, the parallax error listed in the database doesn't include the systematic error. This is said clearly in, for instance, the main paper presenting the data release (near the beginning of section 3):

Quote
The typical uncertainty for the parallaxes is 0.3 mas, where it should be noted that a systematic component of 0.3 mas should be added (see Sect. 6).

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