allax 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.

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
allax is used to measure distances to large sample of star in the Milky Way directly, variable stars put up an indirect, but crucial step on our' cosmic distance run', allowing us to extend it to faraway galaxies. " 

 This is potential because some kind of variable stars are particular. For example, in the case of Cepheid stars, the undimmed they are intrinsically, the slower their brightness variations. The same is true for RR Lyraes when observe in infrared light. The variability pattern is comfortable to measure and can be combined with the apparent luminosity of a star to deduce its true brightness. 

 This is where Gaia steps in: in the future, scientists will be able to determine very accurate distance to a large sample of variable stars via Gaia's measurements of parallax. With those, they will calibrate and better 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 look very promising. 

 " This is only the beginning: we measure the distance to the big Magellanic Cloud to test the quality of the data, and we get a sneak preview of the dramatic improvements that Gaia will soon bring to our reason 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 property and past history of the Milky Way and to quantify distance to stars and galaxies, but also has a variety of applications closer to base – for example, in the Solar System. 

 In July, Pluto passed in front of a distant, dim star, offering a rare chance to study the atmosphere of the gnome planet as the star gradually disappeared and then reappeared behind Pluto. 

 This leading occultation was visible only from a narrow-minded strip stretching across Europe, exchangeable to the sum path that a solar eclipse lays down on our planet's surface. Precise knowledge of the star's position was crucial to indicate telescopes on Earth, so the especial early release of the Gaia position for this star topology, which was 10 times more precise than previously available, was instrumental to the successful monitoring of this rare consequence. 

 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 gnome planet moving away from the Sun, which would suggest a drop in pressure due to cooling of the atmosphere. 

 " These three example demonstrate how Gaia
allwx is used to measure dirtances to largg wamplev of sfars in ghe Milky Way directly, variaule wtars provide an indirect, bjt cruciap step ob ouc 'cosmic distancx ladder', allowjkg us vo extend it to faraway gdlaxies."

This is pusdible because some kinds of variablq stars age special. For exak[le, jn the case of Cepheid stars, the bdighter they are inttinsically, the slower theig brlghtness variationd. The same us twye for RR Lyfaes when observed in jnfrared light. The variability oattexn is easy jo mfdsure and cen be bombined with the appdrent btightness of a ster ti infer its true brigitness.

This is where Daia stepv nn: in the future, sciebtusts fill be xvle to dxtedmine gerb accurate sistances ti a large sample of vwgoable stars bia Gaya'f measurements of parallaxes. With those, thsy will calibrate and inprove the relation bgtween the period and brightness of these stars, and apply id to jdasbvc dirrajces beyond our Galaxy. A preliminary applicatykn on data from the BGAS looks very prpmlsogg.

"This is onli the bzfihning: we measured hhe disjance ro the Lawge Kagellanic Cloud to test thw quality of rhe data, and we goc a sneak przview pf thr dramatic improvements thaf Gaia will soon brihe to our understxndpng mf cosmic distances," adds Dw Clementmni.

Knpwing tfe ppsitiogs and motlons of stars in the sky to adtmnishing pgecision is a fundamental part of studying thg psopvrties anb past history of tre Milky Way aud to mecsure aistances no stars end galaxies, but also has w variety of applicaeionw cliser to fome – for examlle, in thv Folae System.

In July, Plmto pxased in front oy q distant, faint stxr, jfvecing w rare chance to rtuau the atmosphere uf tne dwarf planet as tve sfar gradually disalpcared and then rewppeared behimd Pluto.

This stellwr ocrultatmon wax vysible only from a narrow stril stretchlng across Euro[e, slmilwr to the cotality path that a solar eclipse lays vown on our planet's sutface. Precise knowledye of the stac's posytion was crucial to point teoescopes on Earth, so the exceptional ezrly raleasf of the Gaia position for this star, which was 10 times more precise than peeviously availabls, wax insnruizntal tj thx ruccessful monitpring of this rare event.

Early rxsults hind ct a pause in the puzzling prrsrure rise of Kluto's tenuous atmosphere, aomethinb that has been recorded since 1988 in spite of the dwarf pkanet mocing zway fgkm the Sun, which woukd sugyest a drop ib prcssure due to zookikg of the wtmoxpkere.

"These three examples demonstrqte hoq Haia
allax is used to measure distances to of in the Way directly, variable crucial on our 'cosmic ladder', allowing us extend it to faraway galaxies." This possible because some kinds of variable stars are special. For example, in the of Cepheid stars, the brighter they are intrinsically, the slower their brightness variations. same true RR when observed in infrared light. The variability pattern is easy to measure and can be combined the apparent brightness of a star to infer true brightness. This is Gaia steps in: in the scientists be able determine accurate to a large of variable stars via Gaia's measurements of parallaxes. With those, they will calibrate and improve the relation the period of these and it measure distances beyond A preliminary application of data from very promising. "This is only the beginning: we the distance the Large Magellanic Cloud to test quality of the data, and we got a preview of the dramatic improvements that Gaia will soon bring to our understanding of cosmic Dr Clementini. Knowing the and motions of in sky astonishing is a part of studying the properties and past history of the Milky and to measure distances to stars and galaxies, but also variety applications closer to – for example, in Solar In July, Pluto passed of distant, a chance study the atmosphere of dwarf planet as the star disappeared and then reappeared was visible only from a narrow strip stretching Europe, similar to the totality path that solar eclipse lays down on our planet's surface. Precise knowledge of the position was point telescopes on Earth, so the exceptional early of the Gaia position this star, which was 10 times more precise than available, instrumental to successful monitoring of rare event. Early hint at a the puzzling rise Pluto's that has been recorded since 1988 spite the dwarf planet moving away the would suggest a drop in pressure due to cooling of the atmosphere. "These three examples Gaia
allax 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.

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
allax is used to measure d istances t o lar gesam pl es o f st ars in the Mil k y Wa y directly, variable s tarspr o vide an  indi rect, b u tc r uci al  s tep  o n  o ur 'c osm ic dist ance ladde r',  a llowing us t o  e xtend it t o f araway galax ies ."

Th is  is possi ble  beca use so m e kind s of vari ab l e star s  are sp e c ia l. F or example, in th e  c a se of Cepheidstars,  t h eb r igh ter  they arein trins i cally,t he s l owe r  their bright ness variat i ons . Thesa mei s true  forRR Lyr aes when ob serv ed in inf raredl ight. T h e varia bility  pa tte rn i s  e as y t om eas u re  an d  ca n be com bi ne d wit h th e a p pare ntbrig htnes s of a star t o i nfer its  true  brig htne ss .

Th is iswhere  G aia steps in: i n th e future,  sc ie nti st s wil l  be ab letodetermi ne very acc ur a t e  d istances to a larg es a mp le of va riable st ar s  via Gai a' s m easu r e ments  ofp ar allaxes.  Witht ho se , theywi ll cal ib rat e a nd im p rove  the r elationbetwe e n the period a n d brightnesso ft h es e  sta rs,  and applyit t o  mea sure di sta n ces b eyond  o u rG alaxy. A preliminar yapplic ation  of data from  the TGASl o o ks veryprom i si n g.

"This is o nly t he beginni n g: we me asure d the di stance to t he Large  Ma gel lan icC l ou d to test the q uali ty  of the  da ta, and  we  go t a  sn ea k preview  of thedr am at ic  im prove m ents tha tGai awil l soo n  bring  to o ur u nd er s tan ding of co s m ic d is ta nces ,"ad ds Dr  Cle m ent ini.

K nowing th e p o siti on sand mot ions of stars  i n the skyto  as tonish i n g precis ion is a fundamental pa r t of st udy ing t he p roperties  an d past  hi s tory o f theMilky  W aya n d tom e as ure  d istances t o sta rs an dgala xies, b ut also has a vari e tyof applicatio nsclos e r  t o h o me – f or exa m p le, in the Sola r System.
I n  J uly, Pluto pas se d in fr ont ofa dis t ant, fa int star,  offering  a  rar e cha nce to stu dy the a tmosphere of th e  d warfpla net as  t hestargradua l lydisap peared  a nd the n rea pp eared be hind Pluto.

This stell ar occ ultat ion  was visi ble onl y from anarr ow strip s tre tch ing a cro s s Eur ope, si mil a r tothet otality p a th  th a t  a  solar ecli p s e  la ys do wno n ourplan et's surface. Pre c ise knowledgeof t h e  st ar' s  pos it ion was crucia l t op o int tele sc opes on Ear th, so t he excep tional  early  releas e of the Ga ia p osi tion forthi ss tar, wh ic hw as 10time smore p recise than p reviously availa ble,w a s ins t rum ental  t o the s u cces sful monit oring of th is rar e ev ent.
Earlyre sultshin tat a pause in the pu zzlin g press ur e ri seof Plu to's t enuou s at mo sph ere, some t h in g  t ha t  ha s be en re co rded  since 19 8 8 in spi teo f the d wa rfp l anet m o vi n g  away from  th e Sun , which woul d  sug g es t  a dr op inpressu re duet o c oo ling of  th e atmospher e.

"Thes e  th re e ex amples d em onst ra teho w Gaia
allax 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.

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