Smallest Known Star Discovered

This week astronomers at University of Cambridge announced discovery of EBLM JO555-57Ab, the smallest star ever identified by science. To ponder EBLM JO555-57Ab, cast an eye of imagination 600 light years across the cosmos. Recline in upholstered comfort, search for unmistakable washes of sunlight emanating from a cosmic body smaller than Jupiter, barely larger than Saturn. Marvel at the fickle nature of our universe while dismissing notions of mandatory solar enormity. Despite a meager footprint, know that a star, is a star, is a star.

Demure as EBLM JO555-57Ab appears, mass not size determines star status. More mass = more gravity, exceptional gravity smashes particles together creating nuclear fusion which releases energy as light, radiation and solar wind. See How Stars Work at –

Alexander Boetticher, lead study author doubts stars get much smaller than EBLM JO555-57Ab.

“Our discovery reveals how small stars can be. Had this star formed with only a slightly lower mass, the fusion reaction of hydrogen in its core could not be sustained, and the star would instead have transformed into a brown dwarf.”

EBLM JO555-57Ab resides in a double star system, but for this critical detail, astronomers might never have noticed EBLM JO555-57Ab passing in front of her larger companion star. Curiously, dim, coolish, barely a star like our now know smallest star, are the “best candidates” for finding Earth sized exoplanets with surface water. Boetticher adds –

[EBLM J0555-57Ab] is smaller, and likely colder, than many of the gas giant exoplanets that have so far been identified. While a fascinating feature of stellar physics, it is often harder to measure the size of such dim low-mass stars than for many of the larger planets. Thankfully, we can find these small stars with planet-hunting equipment, when they orbit a larger host star in a binary system.

It might sound incredible, but finding a star can at times be harder than finding a planet.

Artist’s concept of newly-measured smallest star, called EBLM J0555-57Ab, in contrast to planets Jupiter and Saturn and to the small, cool star Trappist-1, known to be home to at least 7 planets. Image via University of Cambridge.

How Many Stars Can We See?

I’ll never forsake stars, they’re as much who I am as the air I breath. A rural child, raised decades before electronic distractions – stars were my universe. A portal entered with nothing more than imagination. Mythology danced before my eyes – never forced, elusive or fleeting. Constellations made sense of history – I gazed upon stars just as ancients once looked to the cosmos for answers. Taken for granted my stars would never fade. Not until decades of emptiness met circumstance in the middle of night- a abandoned highway somewhere in Arizona, did I realize how I longed for my stars. Unfettered by light pollution – I welcomed lost stars.

Reality of light pollution – equal parts inevitable and devastating, led me to ponder how many stars we can see. The answer is – not many. Get away from urban illumination, give yourself half an hour or so adjusting to darkness – maybe you’ll see a few thousand. Deposit yourself in the middle of an Arizona wasteland, undoubtedly that number rises. The trouble is – few of us bother with Arizona nights.

Ponder the day when all who remember stars are gone, when no child rests on summer’s night grass becoming one with the ancients. Imagine not finding the North Star or plucking Orion’s belt from the sky.

San Francisco night sky as viewed without light pollution. – Thierry Cohen

Click on the link to view images of night sky sans light pollution images of 10 major cities by Thierrry Cohen…