Daleki objekat orbitira oko Sunca

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Astrolozi su pronasli veliki objekat u Solarnom sistemu.To je "pozdravljeno" kao veliko otkrice.



Details of the object are still sketchy. It never comes closer to the Sun than Neptune and spends most of its time much further out than Pluto.

It is one of the largest objects ever found in the outer Solar System and is almost certainly made of ice and rock.

It is at least 1,500km (930 miles) across and may be larger than Pluto, which is 2,274km (1,400 miles) across.

The uncertainty in estimates of its size is due to errors in its reflectivity.

It might be a large, dim object, or a smaller, brighter object. Whatever it is, astronomers consider it a major discovery.

In 2004 scientists discovered Sedna, a remote world that is 1,700 km across.

Frantic checking

Two groups of scientists will be claiming the latest discovery.

It was picked up by astronomers of the Institute of Astrophysics in Andalusia as part of a survey of the outer solar system for new objects that they have been carrying out since 2002.

"We found a bright, slow moving object while checking some older images of our survey for Trans-Neptunian Objects," Jose-Luis Ortiz, one of the objects co-discoverers, told the BBC News website.

It was subsequently designated 2003 EL61.

However, American astronomers also appear to have detected it.

The same team that found Sedna have designated it K40506A after it was picked up by the Gemini telescope and one of the twin Keck telescopes in Hawaii.

They are due to present their findings at a conference in Cambridge in September.

Because the object is relatively bright, astronomers are frantically checking other observations that may have picked it up, particularly robotic sky surveys.

http://news.bbc.co.uk/1/hi/sci/tech/4726733.stm

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10ta (11ta) planeta? Ili jos jedna ateroidcina koja orbitira oko Sunca... Neka je klasifikuju sto pre, bas me interesuje

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An object possibly twice the size of Pluto has been found - hiding in plain sight. The discovery could be the biggest world in the Kuiper belt of rocky objects that orbit the outer reaches of the solar system.

The find suggests more such objects are waiting to be discovered and is likely to reignite the fierce debate about what constitutes a planet.

On Thursday, an email with the subject, "Big TNO discovery, urgent" was sent to a popular astronomy mailing list. The message described the discovery of a "very bright" object that was creeping along slowly beyond the orbit of Neptune - making it a Trans-Neptunian Object, or TNO.

Its exact size cannot be determined because the reflectivity of its surface is not known. But if the reflectivity is as dim as most other distant, rocky objects that have been studied, it could be twice as wide as Pluto, which is about 2300 kilometres across.
Sleepless night

Jose-Luis Ortiz, an astronomer at the Sierra Nevada Observatory in Spain, and colleagues discovered the object when they re-analysed observations they had made in 2003. Then, they scoured older archives and found the object in images dating back to 1955.

Based on these so-called "precoveries", they calculated the object's orbit and sent urgent emails asking people around the globe to observe the new find.

Amateur observers Salvador Sanchez, Reiner Stoss, and Jaime Nomen found it on Thursday using a 30-centimetre telescope in Mallorca, Spain. "I am not going to sleep tonight," said Stoss, a mechanical engineering student in Darmstadt, Germany. "To find an object bigger than Pluto - it's like the X Prize," he said, referring to the $10 million prize for private spaceflight won in 2004.

The observations were then verified by the International Astronomical Union's Minor Planet Center (MPC) in Cambridge, Massachusetts, US, which designated the object 2003 EL61.
Time to move

The MPC reports the object is about 51 Astronomical Units from the Sun - 1 AU is the distance between the Earth and the Sun. Its orbit brings it comes as close to the Sun as 35 AU, while Pluto maintains an average distance of about 39 AU. "Someone should have found this before," Brian Marsden, director of the MPC, told New Scientist.

One reason they did not is the object's speed, suggests Stoss. Many surveys of Near Earth Objects take a trio of images spaced 20 minutes apart to search for telltale movement in relation to background stars.

But 2003 EL61 is too far away to detect its progress in that time. Ortiz's survey compares images taken a day apart. "They give the object time to move," Stoss says.

Another reason may be the plane of the object's orbit, says Tommy Grav, an astronomer at the University of Hawaii in Manoa, US. That plane is tilted by 28° with respect to the orbital plane of most planets, where surveys tend to scan the skies for Near Earth Objects.
Off kilter

2003 EL61 is even more off-kilter than Pluto, which orbits in a plane tilted by 17°. "Pluto was pushed out of the plane of the solar system when Neptune moved outwards" soon after the solar system formed, Grav told New Scientist. "It's possible this object has suffered something similar."

The discovery, coupled with other recent finds such as Sedna and Quaoar, suggests other large objects may lurk in the murky region beyond Neptune.

"Some people have claimed we'd never find something as bright as this out there," says Grav. "But there may be something even further out that's moving so slowly we haven't seen it yet."

And the discovery is likely to revive previous fierce debates about what constitutes a planet and even how astronomical objects are named. "But don't even start that discussion," Stoss jokes. He says future observations of the object's colour and brightness could reveal its true size, shape, rotation period, and any companion moons.




http://www.newscientistspace.com/article.ns?id=dn7751

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Evo malo na srpskom ...

Kamenita hladna veca od Plutona.Prema tvrdnji naucnika koji su otkrili kako se krece oko Sunca, ovo je i najudaljeniji objekat u Solarnom sistemu. Od Sunca je udaljena vise od 14 milijardi kilometara, sto je tri puta dalje os Plutona i 97 puta od Zemlje.

Otkrili su je Majkl Braun iz "Kalteka", Cadvik Truhiljo iz "Dzemini" opservatorija Havaji, i Dejvid Rubinovic sa univerziteta Jejl.

Prema rijecima dr. Majkla Brauna otkriveni objekat je veci od Plutona, ali je priznao da bi nazivanje objekta planetom, koja je vjerovatno sastavljena od stijena i leda, moglo da izazove polemiku medju strucnjacima. Ipak, Braun kaze da ako se utvrdi da je ovaj udaljeni objekat ipak samo asteroid, onda slicnu sudbinu ceka i Pluton. Dakle u nasem sistemu od ovog otkrica postoji osam ili deset planeta.

Nova planeta privremeno je nazvana 2003 UB 313, a njna putanja je pod dosta velikim uglom, zbog cega najvjerovatnije i nije ranije uocena.

Dr Braun je rekao da imaju iime koje su predlozili za planetu, ali nije zelio da otkrije koje je, prije nego sto to i zvanicno odobri Internacionalna astronomska unija.

Nezvanicno, astronomi su je do sada nazvali Ksena, po televizijskoj seriji o grckoj princezi ratnici, koja je bila popularna u vrijeme kada su zapoceli sistematicno istrazivanje u svemiru 2000. godine. "oduvijek smo zeljeli da nesto nazovemo Ksena", kaze dr Braun. "To je ime koje nam se zaista svidja i zelimo da ga zadrzimo".

2 Avgust,vecernje novosti

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Nova planeta

Njen sjaj govori da je veća od Plutona, koji ima prečnik 2.250 kilometara, a izvesno je i da nova planeta nema prečnik veći od 3.000 kilometara - tvrde američki naučnici.
Nova planeta prvi put je registrovana 21.oktobra 2003. godine, a njeno kretanje astronomi Majkl Braun, Čad Truiljo i David Rabinovic ponovo su zabeležili tek 15 meseci kasnije, tačnije 8.januara 2005. godine.
Od Sunca je "2003 UB 313" udaljena 14,5 milijardi kilometara i ima veoma nagnutu putanju, ističu stručnjaci, što je i jedan od razloga zbog čega objekat do sada nije bio otkriven. Nalazi se u sazvežđu Kit i prema nezvaničnim procenama istraživača, prekrivena je zaleđenim metanom, baš kao i najmanja planeta sunčevog sistema Pluton, koja je otkrivena 1930.godine.
Tim astronoma koji je otkrio desetu planetu podneli su predlog imena novootkrivenog objekta Međunarodnoj astronomskoj uniji, ali ne žele da ga otkriju dok Unija ne donese odluku.

http://www.novosti.rs/vest.php?vest=43182&rubrika=Svet

Dopuna: 15 Avg 2005 21:40

Veca nego sto se ocekivalo
An observational error may have understated the size of the tenth planet – if "planet" is in fact what astronomers finally decide to call it.

The upper limit on the size of the object, temporarily called 2003 UB313, was earlier set at 3000 kilometres following the Spitzer Space Telescope's failure to spot any infrared source at its location. But as its discoverer Mike Brown notes on his website, the telescope was actually pointed at the wrong place, so the object could actually be bigger than that.

The Spitzer observations were made before the object was entered in public data bases, so Brown's group at Caltech, US, had to specify the positions of it and two other giant Kuiper Belt objects.

Spitzer was aimed correctly at two of them - but somewhere along the line an error crept in with the location of 2003 UB313. "The mistake was caught by one of the many extremely careful members of the Spitzer Science Center," Brown writes. Spitzer will check the right spot to see 2003 UB313 later in August.
Heat and light

The space telescope’s infrared observations are critical for estimating the object's size. Asteroids, comets, and Kuiper belt objects vary widely in how much visible light they reflect, but internal heat makes them glow faintly in the infrared.

Knowing the object's distance from the Sun, astronomers can calculate its surface temperature, so measuring its infrared brightness reveals its size.

But Spitzer still may not spot 2003 UB313. Its spectrum resembles Pluto's, and if it reflected the same fraction of light – 60% – its known brightness would reveal it to be only 2860 kilometres in diameter, and too small to be seen. This would nevertheless make it bigger than Pluto, which is 2285 km wide.

But if it reflected the same fraction of light as Pluto's moon Charon, just 38%, 2003 UB313 would measure 3550 kilometres across, making it visible to Spitzer’s infrared instruments.
Urgent deliberations

Brown's group is also looking at 2003 UB313 at much longer wavelengths – at the upper end of the microwave band – using the 30-metre ground-based IRAM telescope. This too can determine the object’s heat output, though at the signal will be fainter than that sought by Spitzer.

The discovery of 2003 UB313 has added urgency to the deliberations of a working group that had been pondering the definition of a planet. Until that group comes to a decision, the International Astronomical Union says "the object will not be given an official name".

Approval of a name would then fall to one of two IAU panels - on minor planets or full-fledged planets - which have different criteria. The planet panel wants to continue naming planets after Greek and Roman gods. Brown says most of the good ones are taken, but "we have a couple of interesting choices in mind".
Ovde