The search forexoplanetshas been on-going for decades . To day of the month , thousands of themhave been catalog , range from the potentially habitable to the decidedly unusual andhostile .
The uncovering of the very first exoplanets , two worlds orbit around aviolent pulsar , was announce in 1992 , with the first exoplanet orb a Sun - like star being announced in 1995 . However , as a curious tale upload to thearXivserver reveals , the very first hints of planets outside our Solar System could have accidentally been hear as far back as 1917 – astronomers at the fourth dimension just did n’t bring in it .
Back when the First World War was come near its conclusion , a Dutch - American uranologist name Adriaan van Maanen spent his time diligently snap the virtuoso at the Mount Wilson Observatory near Los Angeles . He serendipitously discovered one of the firstwhite dwarf , a end of a star like our own and the nearest known to us , lingering in the cosmos 14 faint - old age aside . This stellar remnant was named “ van Maanen 2 . ”
“ With 20–20 hindsight , it is now possible to say that the first observational meter reading – by any means – of the existence of an extrasolar planetal system came almost a hundred ago when van Maanen distinguish and observe the spectrum of the approximate single snowy dwarf to Earth , ” compose Ben Zuckerman , a professor of physics and astronomy at the University of California , Los Angeles ( UCLA ) , and the composition ’s author . A recentreviewof dust interacting with white dwarf confirms this notion .
The 1917 spectrum of van Maanen 2 , pictured here as the thin , sinister line in the eye of the zoom - in box . The little gaps represent absorption melodic phrase for grueling elements . Carnegie Institution for Science
Maanen used a methamphetamine home base to capture the white dwarf ’s emanation spectrum , which is its escaping radiation syndrome . These spectrum permit astronomers not only to discover the chemic make-up of the star , but they also expose anything that gets in its way – a dust cloud , for exercise , or even a planet . These obstacles in the line of products of sight show up as “ absorption line ” on the spectral image .
At the time , a few mysterious absorption short letter went unnoticed by the astronomer . The plate was stored off , and Maanen go along his work until he died in 1946 . Fast forward to 2014 , and Zuckerman was spend metre look for the plate , hop to expend it as part of a scientific symposium .
While examining it , Zuckerman noticed these previously unobserved absorption lines , which seemed to indicate that van Maanen 2 contained heavy elements , like calcium , magnesium , and iron . Although these can be observed in other star type , bloodless midget should only contain hydrogen and atomic number 2 . So where were these additional elements coming from ?
The spectrum of van Maanen 2 reassess by the Very Large Telescope ( VLT ) . These peaks and troughs reveal the previously unexpected bearing of heavier elements . Ben Zuckerman
In the last 12 years , astronomers have realized that some white dwarfs can be “ polluted ” by nearby rings of rough debris , much of which inescapably tumbles into the star and pollute it . This junk originally do from the stiff of world objects , which would contain these heavy elements .
assign two and two together , Zuckerman had his own constantan moment : van Maanen 2 was a white midget surrounded by rocky planetary junk that was “ polluting ” it . This , by most accounts , think of that the first planetary system outside of our own Solar System was discovered not in 1992 , but 1917 – 75 years earlier .
Although whole exoplanets themselves had not been detected , they may have once been there in rules of order to create planetal debris in the first berth .
