An exoplanet that was once like a star
Astronomers, using WISE data, have discovered a strange exoplanet that is now as cool as a rocky planet, but was once as hot as a red dwarf star.
The current temperature of the object is 100-150 degrees Celsius, intermediate between that of the Earth and Venus. But the object shows evidence of a possible ancient origin, implying that a large change in temperature has taken place. In the past this object would have been as hot as a star for many millions of years.
Called WISE J0304-2705, the object is a member of the recently established “Y dwarf” class – the coolest stellar temperature class yet defined, added to the end of the sequence OBAFGKMLT (for historical reasons this is not in alphabetical order but follows a decline in temperature from O to T). Although its temperature is not far off that of our own world, the object is not like the rocky Earth-like planets and instead is a giant ball of gas like Jupiter.
As cool as this discovery is (no pun intended), I am most enlightened by the information in the second paragraph above. I had not realized that astronomers had added L, T, and Y classes to the low temperature end of their stellar classification system. For those new to astronomy, you remember the sequence of the first seven classes with the phrase “O Be A Fine Girl Kiss Me”. I wonder what how we can amend this phrase to include the L, T, Y, classes?
On Christmas Eve 1968 three Americans became the first humans to visit another world. What they did to celebrate was unexpected and profound, and will be remembered throughout all human history. Genesis: the Story of Apollo 8, Robert Zimmerman's classic history of humanity's first journey to another world, tells that story, and it is now available as both an ebook and an audiobook, both with a foreword by Valerie Anders and a new introduction by Robert Zimmerman.
The ebook is available everywhere for $5.99 (before discount) at amazon, or direct from my ebook publisher, ebookit. If you buy it from ebookit you don't support the big tech companies and the author gets a bigger cut much sooner.
The audiobook is also available at all these vendors, and is also free with a 30-day trial membership to Audible.
"Not simply about one mission, [Genesis] is also the history of America's quest for the moon... Zimmerman has done a masterful job of tying disparate events together into a solid account of one of America's greatest human triumphs."--San Antonio Express-News
Astronomers, using WISE data, have discovered a strange exoplanet that is now as cool as a rocky planet, but was once as hot as a red dwarf star.
The current temperature of the object is 100-150 degrees Celsius, intermediate between that of the Earth and Venus. But the object shows evidence of a possible ancient origin, implying that a large change in temperature has taken place. In the past this object would have been as hot as a star for many millions of years.
Called WISE J0304-2705, the object is a member of the recently established “Y dwarf” class – the coolest stellar temperature class yet defined, added to the end of the sequence OBAFGKMLT (for historical reasons this is not in alphabetical order but follows a decline in temperature from O to T). Although its temperature is not far off that of our own world, the object is not like the rocky Earth-like planets and instead is a giant ball of gas like Jupiter.
As cool as this discovery is (no pun intended), I am most enlightened by the information in the second paragraph above. I had not realized that astronomers had added L, T, and Y classes to the low temperature end of their stellar classification system. For those new to astronomy, you remember the sequence of the first seven classes with the phrase “O Be A Fine Girl Kiss Me”. I wonder what how we can amend this phrase to include the L, T, Y, classes?
On Christmas Eve 1968 three Americans became the first humans to visit another world. What they did to celebrate was unexpected and profound, and will be remembered throughout all human history. Genesis: the Story of Apollo 8, Robert Zimmerman's classic history of humanity's first journey to another world, tells that story, and it is now available as both an ebook and an audiobook, both with a foreword by Valerie Anders and a new introduction by Robert Zimmerman.
The ebook is available everywhere for $5.99 (before discount) at amazon, or direct from my ebook publisher, ebookit. If you buy it from ebookit you don't support the big tech companies and the author gets a bigger cut much sooner.
The audiobook is also available at all these vendors, and is also free with a 30-day trial membership to Audible.
"Not simply about one mission, [Genesis] is also the history of America's quest for the moon... Zimmerman has done a masterful job of tying disparate events together into a solid account of one of America's greatest human triumphs."--San Antonio Express-News
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