Billion Star Sky Surveyor Launches

Astronomers plan on rewriting the star-charts with the latest space telescope, which aims at unlocking the secrets behind the birth and evolution of our home galaxy.

Europe’s new Milky Way Galaxy mapping-mission, called Gaia, is about to embark on a space mission that should create the most detailed three-dimensional star chart of the nearest billion stars. Each and every target star will have its position, distance, movement, and changes in brightness followed at least 70 times over a five year period. (See also ”Mystery Deepens Over Where Sun Was Born“.)

The two-ton space telescope, launched on Thursday on a Russian Soyuz rocket, headed into orbit from the European Space Agency’s spaceport in French Guiana.

Light from the cosmos will focus onto Gaia’s eye, a single digital camera equipped with a billion-pixel CCD chip-set, the largest and most sensitive light-detector ever flown in space.

more…

> launched on Thursday …

What!
I thought Gaia launched in Dec 2013 and reached final orbit Jan 2014. At least, that’s what I’ve been telling everyone.

According to Wikipedia: Gaia was successfully launched on 19 December 2013 at 09:12 UTC. About three weeks after launch, on 8 January 2014, it reached its designated orbit around the SEL2 point. Testing and calibration phase, started while Gaia was en route to SEL2 point, will continue until May 2014.

Gaia is a superb spacecraft.

• I thought Gaia launched in Dec 2013 and reached final orbit Jan 2014. At least, that’s what I’ve been telling everyone.

Yeah, captain yesterday is on top of the current news…

“Billion Star Sky Surveyor Launches
Posted by Andrew Fazekas in StarStruck on December 19, 2013”

Looks at date

I am embarrassed now

furious said:

• I thought Gaia launched in Dec 2013 and reached final orbit Jan 2014. At least, that’s what I’ve been telling everyone.

Yeah, captain yesterday is on top of the current news…

“Billion Star Sky Surveyor Launches
Posted by Andrew Fazekas in StarStruck on December 19, 2013”

I’ll take the Captain Yesterday Award for today

That might teach me to look at the dates of articles I post

Ah, I see, CN had found an old News article. “With 100 individual mini-detectors working in concert, star positions will be measured with stunning precision, down to 10 micro arc-seconds of accuracy. This is an astonishing step up in accuracy.”

No kidding it’s an astonishing step in accuracy!

Gaia is the successor to an earlier ESA space mission called Hipparcos operated from 1989 to 1993. The best accuracy of Hipparcos, and of subsequent follow-ups using the Chilean telescopes at Paranal, was 600 to 1000 micro arc-seconds, which is sixty to a hundred times as poor as Gaia will manage. This difference and other improvements will allow Gaia to find accurate positions for about a billion stars, as against a “mere” 118,000 stars at high accuracy and 2.5 million at low accuracy from Hipparcos.

That means that Gaia will be able to find the distances to a sizable fraction of the total number of stars in the Milky Way, at distances as far away as the galactic centre. For the first time we’ll have a superbly accurate picture of this side of the Milky Way, not just a blurry picture derived from the Doppler shift of gaseous hydrogen. Because of the Cepheid variable stars in this survey (and other stars) this will even more accurately pin down the Hubble constant, giving us a better picture of the whole universe.

CrazyNeutrino said:

Looks at date

I am embarrassed now

At least it wasn’t 1 April.

Here’s what Wikipedia says about distances to Cepheid variables:

“Uncertainties in Cepheid determined distances. Chief among the uncertainties tied to the Classical and Type II Cepheid distance scale are: the nature of the period-luminosity relation in various passbands, the impact of metallicity on both the zero-point and slope of those relations, and the effects of photometric contamination (blending) and a changing (typically unknown) extinction law on Cepheid distances. All these topics are actively debated in the literature. These unresolved matters have resulted in cited values for the Hubble constant (established from Classical Cepheids) ranging between 60 km/s/Mpc and 80 km/s/Mpc. Resolving this discrepancy is one of the foremost problems in astronomy since the cosmological parameters of the Universe may be constrained by supplying a precise value of the Hubble constant.”

Roughly 1 in every 400,000 stars is a Cepheid variable, so Gaia ought to be able to determine the distances to about two thousand of them.

CrazyNeutrino said:

Europe’s new Milky Way Galaxy mapping-mission, called Gaia, is about to embark on a space mission that should create the most detailed three-dimensional star chart of the nearest billion stars. Each and every target star will have its position, distance, movement, and changes in brightness followed at least 70 times over a five year period.

big data, man. big data.

Soso said:

CrazyNeutrino said:

Europe’s new Milky Way Galaxy mapping-mission, called Gaia, is about to embark on a space mission that should create the most detailed three-dimensional star chart of the nearest billion stars. Each and every target star will have its position, distance, movement, and changes in brightness followed at least 70 times over a five year period.

big data, man. big data.

Wonder what the go is now with Gaia, now that been a few months?

I will have to check it out

CrazyNeutrino said:

Wonder what the go is now with Gaia, now that been a few months? I will have to check it out.

Latest news on Gaia. Gaia

As part of the commissioning process, Gaia photographed a region towards the galactic centre (left image) and automatically identified star positions in that image (right image). Stars are found down to visual magnitude 20. A few of the stars in each image is used to ensure that Gaia is always pointing in the desired direction.

Earlier observations of Gaia seen from the ground in animated gifs from all around the world.

I find the first of these particularly interesting because not just does Gaia reduce in brightness by a factor of 100, but there’s another moving object in the gif.

mollwollfumble said:

CrazyNeutrino said:

Wonder what the go is now with Gaia, now that been a few months? I will have to check it out.

Latest news on Gaia. Gaia

As part of the commissioning process, Gaia photographed a region towards the galactic centre (left image) and automatically identified star positions in that image (right image). Stars are found down to visual magnitude 20. A few of the stars in each image is used to ensure that Gaia is always pointing in the desired direction.

Thanks mollwollfumble

A bit off topic

If anyone is interested

I came across an android app on google play store called Asteroid Tracker

Asteroid Tracker

there is also SatTrack

It gets its data from heavens above website

http://www.dailymail.co.uk/news/article-2596354/Close-call-Amazing-video-moment-skydiver-nearly-hit-falling-METEORITE-just-parachute-opens.html

wookiemeister said:

http://www.dailymail.co.uk/news/article-2596354/Close-call-Amazing-video-moment-skydiver-nearly-hit-falling-METEORITE-just-parachute-opens.html

Awesome, If that is verified, just awesome