Long ago, in a solar system far away, a star named WD 1145 was much like our own warm yellow sun. Today it's a white dwarf, and using data observed by the Kepler space telescope, NASA has discovered it may be steadily ripping the rocky planets around it to shreds. Given some of the similarities between the system and ours, WD 1145's epic destruction may provide a mind-boggling glimpse into the (hopefully distant) future fate of the Earth.
Discussing WD 1145 in Slate's "Bad Astronomy" blog, Astronomer Phil Plait described the violent creation of a white dwarf star, in which a star is stripped of its outer layers, "exposing the star’s über-dense but intensely hot core to space."
If a planet orbiting a star undergoing this process survives the stripping of the layers, Plait says it will still "get a white-hot blowtorch to the face as its reward."
That's exactly what's happening in the WD 1145 star system, according to Plait—the white dwarf is "vaporizing its planets."
The brutal death of WD 1145 was discovered in much the same way Kepler data revealed the existence of the intriguing KIC 8462852, a star that behaves strangely enough to prompt talk of "alien megastructures" from serious astronomers. Phil Plait describes the strange dips in light output from the white dwarf system:
"For one thing, the blips in WD 1145’s starlight are periodic (the other star shows no repeating periodicity in its diminution), occurring every 4.5 hours or so. In fact, there are clusters of them, six at least, with periods of roughly 4–5 hours. The amount of starlight blocked varies, but at one point astronomers saw a whopping 40 percent dip in light!"
The Earth-sized white dwarf might bring to mind the Death Star from Star Wars, but the idea that the star was similar to the Sun before its transformation also makes it easy to wonder if the rocky planets in this system will one day be torched into rubble.
It's doubtful. "We know Mercury and Venus will be engulfed by the Sun when it turns into a red giant in about seven billion years," writes Plait, "but they might survive the encounter, though considerably more evaporated. Earth won’t get engulfed, but having a red giant star occupying half the sky isn’t exactly conducive to staying chilly."
A future sky lit by an angry red giant isn't more comforting than fiery destruction from a white dwarf, but we'll let whoever's left in a few billion years worry about that.
Photos by Casey Reed / NASA