Just in clip for its25thbirthday , the Hubble Space Telescope has discovered something never observed before : a doubly leading inferno that falls in between novae and supernovae in brightness .
Novae , meaning newfangled , are stars that abruptly brighten . The name comes from the fact that , before telescopes , stars too fainthearted to see would of a sudden become seeable , seem to present new stars . We now have a go at it novae occur when material from a companion starfalls on the aerofoil of a white dwarf , lead to a burst of light that lasts weeks or months .
Supernovae are ten-spot of thousands of times brighter . While some hap through avery different unconscious process , others have a similar trigger to nova . However , in novae just a small section of the ashen midget ’s surface explode , whereas inType Iasupernovaecarbon fusionoccurs in the core . They also fade over a more consistent menses .
So it was gravel when Hubble witnessed an event inEridanuswhose brightness was ten times fainter ( allowing for distance ) than any supernovae , but still a hundred times brighter than the brightest nova . The effusion also faded within two workweek , fast for a nova and unheard of for a supernova .
Then , just to make things really dumbfound , Hubble see something exchangeable seven month subsequently , but this time in the infrared . The observations were made in January and August last year , and deliver at a symposium celebrating Hubble ’s day of remembrance .
“ The combination of properties is puzzling , ” says Dr. Mario Livio , an astrophysicist at the Space Telescope Science Institute in Maryland , toNature . “ I thought about a issue of possible action , but each of them fail . ”
The event happen 7.8 billion light - year aside . Although we can see supernova at that distance , this fainter outburst would have been very unmanageable to clean up were it not for interfere galaxies that do as agravitational lens , making the explosion , and the extragalactic nebula in which it occur , much bright than would otherwise be the showcase .
One effect that is around the right brightness and metre menses is akilonova , which come about whentwo neutron stars clash . However , kilonovas are very rarified consequence .
“ We ’d be very lucky to see one such event , ” says Dr. Steven Rodney of Johns Hopkins University . Two in the same place so soon after each is ludicrously unlikely . One potential account is that what was seen was the same consequence , with the infrared visible light delayed in transmission to us . Rodney enjoin other evidence hint this is unconvincing , but he is not yet uncoerced to rule the possible action out . He has also pull up stakes enter the theory that this is the first example of a whole new class of events .
