The effort to bring Kepler back to life does not look good.
The effort to bring Kepler back to life does not look good.
The effort to bring Kepler back to life does not look good.
Tag: exoplanets
The effort to bring Kepler back to life does not look good.
Engineers will attempt one more try this month to revive one of Kepler’s reaction wheels so that the telescope can resume observations.
Engineers will attempt one more try this month to revive one of Kepler’s reaction wheels so that the telescope can resume observations.
They admit that the odds are not good that the attempt will work, but they are going to give it chance anyway.
Engineers will attempt one more try this month to revive one of Kepler’s reaction wheels so that the telescope can resume observations.
They admit that the odds are not good that the attempt will work, but they are going to give it chance anyway.
Kepler’s planet-hunting predecessor, COROT, has been shut down.
Kepler’s planet-hunting predecessor, CoRoT, has been shut down.
CoRoT suffered a computer failure on November, 2, 2012 and although the spacecraft is capable of receiving navigational commands, the French Space Agency CNES reports it can no longer retrieve data from its 30-centimeter telescope. After a valiant effort to try and restore the computer, CNES announced this week that the spacecraft has been retired. CoRoT’s journey will come to a fiery end as it will be deorbited and it will burn up on re-entry in Earth’s atmosphere.
CoRoT found 32 exoplanets with at least a hundred more candidates still to be confirmed.
Kepler’s planet-hunting predecessor, CoRoT, has been shut down.
CoRoT suffered a computer failure on November, 2, 2012 and although the spacecraft is capable of receiving navigational commands, the French Space Agency CNES reports it can no longer retrieve data from its 30-centimeter telescope. After a valiant effort to try and restore the computer, CNES announced this week that the spacecraft has been retired. CoRoT’s journey will come to a fiery end as it will be deorbited and it will burn up on re-entry in Earth’s atmosphere.
CoRoT found 32 exoplanets with at least a hundred more candidates still to be confirmed.
Astronomers have found a solar system with six exoplanets, three in the habitable zone.
Worlds without end: Astronomers have found a solar system with six exoplanets, three in the habitable zone.
These planets orbit the third fainter star of a triple star system. Viewed from one of these newly found planets the two other suns would look like a pair of very bright stars visible in the daytime and at night they would provide as much illumination as the full Moon. The new planets completely fill up the habitable zone of Gliese 667C, as there are no more stable orbits in which a planet could exist at the right distance to it.
The planets in the habitable zone are all super-Earths.
Update: you can download and read the science paper here.
Worlds without end: Astronomers have found a solar system with six exoplanets, three in the habitable zone.
These planets orbit the third fainter star of a triple star system. Viewed from one of these newly found planets the two other suns would look like a pair of very bright stars visible in the daytime and at night they would provide as much illumination as the full Moon. The new planets completely fill up the habitable zone of Gliese 667C, as there are no more stable orbits in which a planet could exist at the right distance to it.
The planets in the habitable zone are all super-Earths.
Update: you can download and read the science paper here.
The count of candidate exoplanets found by Kepler has now risen another 503 to 3,216, of which only 132 have been confirmed.
The count of candidate exoplanets found by Kepler has now risen another 503 to 3,216, of which only 132 have been confirmed.
These new exoplanets were found before the telescope failed but the data for them is only now being released.
The count of candidate exoplanets found by Kepler has now risen another 503 to 3,216, of which only 132 have been confirmed.
These new exoplanets were found before the telescope failed but the data for them is only now being released.
The Kepler mission has lost its second gyroscope, ending the ability of the telescope to aim precisely.
The Kepler mission has lost its second gyroscope, ending the ability of the telescope to aim precisely. More details here.
The telescope’s primary mission, to stare continuously at one section of sky, looking for exoplanet transits, is over, though it might still be re-purposed for other astronomical research.
The Kepler mission has lost its second gyroscope, ending the ability of the telescope to aim precisely. More details here.
The telescope’s primary mission, to stare continuously at one section of sky, looking for exoplanet transits, is over, though it might still be re-purposed for other astronomical research.
In a NASA contest, a nine-year-old has named asteroid 1999 RQ36 after the Egyptian god Bennu.
A rose by any other name: In a NASA contest, a nine-year-old has named asteroid 1999 RQ36 after the Egyptian god Bennu.
1999 RQ36, or Bennu, is an important asteroid for two reasons. First, NASA is sending an unmanned sample return mission to it in 2016. Second, some calculations suggest the asteroid has a 1 in a 1000 chance of hitting the Earth in 2182.
In other naming news, the private space company Uwingu has launched its “Adopt-a-Planet” campaign.
This open-ended campaign gives anyone in the public—worldwide—the opportunity to adopt exoplanets in astronomical databases via Uwingu’s web site at www.uwingu.com. Proceeds from the naming and voting will continue to help fuel new Uwingu grants to fund space exploration, research, and education.
As noted earlier, they are ignoring the IAU’s stuffy insistence that only the IAU can name things in space.
A rose by any other name: In a NASA contest, a nine-year-old has named asteroid 1999 RQ36 after the Egyptian god Bennu.
1999 RQ36, or Bennu, is an important asteroid for two reasons. First, NASA is sending an unmanned sample return mission to it in 2016. Second, some calculations suggest the asteroid has a 1 in a 1000 chance of hitting the Earth in 2182.
In other naming news, the private space company Uwingu has launched its “Adopt-a-Planet” campaign.
This open-ended campaign gives anyone in the public—worldwide—the opportunity to adopt exoplanets in astronomical databases via Uwingu’s web site at www.uwingu.com. Proceeds from the naming and voting will continue to help fuel new Uwingu grants to fund space exploration, research, and education.
As noted earlier, they are ignoring the IAU’s stuffy insistence that only the IAU can name things in space.
Using Kepler astronomers have found a solar system with five terrestrial-type planets, with two in the habitable zone.
Eden? Using Kepler astronomers have found a solar system with five terrestrial-type planets, with two in the habitable zone.
Using observations gathered by NASA’s Kepler Mission, the team, led by William Borucki of the NASA Ames Research Center, found five planets orbiting a Sun-like star called Kepler-62. Four of these planets are so-called super-Earths, larger than our own planet, but smaller than even the smallest ice giant planet in our Solar System. These new super-Earths have radii of 1.3, 1.4, 1.6, and 1.9 times that of Earth. In addition, one of the five was a roughly Mars-sized planet, half the size of Earth. …
The two super-Earths with radii of 1.4 and 1.6 Earth radii orbit their star at distances where they receive about 41% and 120%, respectively, of the warmth from their star that the Earth receives from the Sun. The planets are thus in the star’s habitable zone; they have the right temperatures to maintain liquid water on their surfaces and are theoretically hospitable to life.
Theoretical modeling of the super-Earth planets, Kepler-62e and Kepler-62f, suggests that both could be solid, either rocky–or rocky with frozen water.
This is big news. Additional info can be found here and here.
Eden? Using Kepler astronomers have found a solar system with five terrestrial-type planets, with two in the habitable zone.
Using observations gathered by NASA’s Kepler Mission, the team, led by William Borucki of the NASA Ames Research Center, found five planets orbiting a Sun-like star called Kepler-62. Four of these planets are so-called super-Earths, larger than our own planet, but smaller than even the smallest ice giant planet in our Solar System. These new super-Earths have radii of 1.3, 1.4, 1.6, and 1.9 times that of Earth. In addition, one of the five was a roughly Mars-sized planet, half the size of Earth. …
The two super-Earths with radii of 1.4 and 1.6 Earth radii orbit their star at distances where they receive about 41% and 120%, respectively, of the warmth from their star that the Earth receives from the Sun. The planets are thus in the star’s habitable zone; they have the right temperatures to maintain liquid water on their surfaces and are theoretically hospitable to life.
Theoretical modeling of the super-Earth planets, Kepler-62e and Kepler-62f, suggests that both could be solid, either rocky–or rocky with frozen water.
This is big news. Additional info can be found here and here.
The International Astronomical Union has issued a press release condemning the commercial efforts of private companies to issue names for exoplanets.
Turf war! The International Astronomical Union has issued a press release condemning the commercial efforts of private companies to issue names for exoplanets.
Recently, an organisation has invited the public to purchase both nomination proposals for exoplanets, and rights to vote for the suggested names. In return, the purchaser receives a certificate commemorating the validity and credibility of the nomination. Such certificates are misleading, as these campaigns have no bearing on the official naming process — they will not lead to an officially-recognised exoplanet name, despite the price paid or the number of votes accrued.
… [snip]
To make this possible, the IAU acts as a single arbiter of the naming process, and is advised and supported by astronomers within different fields. As an international scientific organisation, it dissociates itself entirely from the commercial practice of selling names of planets, stars or or even “real estate” on other planets or moons. These practices will not be recognised by the IAU and their alternative naming schemes cannot be adopted.
Well la-dee-da, how dare anyone else name anything ever in space!
The truth is, the IAU was originally given this function by astronomers to coordinate the naming of obscure astronomical objects, not to provide the official names for every object and feature that will ever be discovered in space. And though the IAU does tend to favor the choices of discoverers, it has in the past also ignored their wishes. (See for example my book Genesis: the Story of Apollo 8, where the IAU rejected the names chosen by the Apollo 8 astronauts, even though those astronauts were the first to actually go and see these features.)
In the end, the names of important features in space will be chosen by those who live there.
Turf war! The International Astronomical Union has issued a press release condemning the commercial efforts of private companies to issue names for exoplanets.
Recently, an organisation has invited the public to purchase both nomination proposals for exoplanets, and rights to vote for the suggested names. In return, the purchaser receives a certificate commemorating the validity and credibility of the nomination. Such certificates are misleading, as these campaigns have no bearing on the official naming process — they will not lead to an officially-recognised exoplanet name, despite the price paid or the number of votes accrued.
… [snip]
To make this possible, the IAU acts as a single arbiter of the naming process, and is advised and supported by astronomers within different fields. As an international scientific organisation, it dissociates itself entirely from the commercial practice of selling names of planets, stars or or even “real estate” on other planets or moons. These practices will not be recognised by the IAU and their alternative naming schemes cannot be adopted.
Well la-dee-da, how dare anyone else name anything ever in space!
The truth is, the IAU was originally given this function by astronomers to coordinate the naming of obscure astronomical objects, not to provide the official names for every object and feature that will ever be discovered in space. And though the IAU does tend to favor the choices of discoverers, it has in the past also ignored their wishes. (See for example my book Genesis: the Story of Apollo 8, where the IAU rejected the names chosen by the Apollo 8 astronauts, even though those astronauts were the first to actually go and see these features.)
In the end, the names of important features in space will be chosen by those who live there.
Using Kepler scientists have discovered a three planet solar system with one planet slightly larger than our Moon.
Using Kepler astronomers have discovered a three planet solar system with one planet slightly larger than our Moon.
Kepler-37’s host star belongs to the same class as our sun, although it is slightly cooler and smaller. All three planets orbit the star at less than the distance Mercury is to the sun, suggesting they are very hot, inhospitable worlds. [The moon-sized] Kepler-37b orbits every 13 days at less than one-third Mercury’s distance from the sun. The estimated surface temperature of this smoldering planet, at more than 800 degrees Fahrenheit (700 degrees Kelvin), would be hot enough to melt the zinc in a penny. Kepler-37c and Kepler-37d, orbit every 21 days and 40 days, respectively.
Using Kepler astronomers have discovered a three planet solar system with one planet slightly larger than our Moon.
Kepler-37’s host star belongs to the same class as our sun, although it is slightly cooler and smaller. All three planets orbit the star at less than the distance Mercury is to the sun, suggesting they are very hot, inhospitable worlds. [The moon-sized] Kepler-37b orbits every 13 days at less than one-third Mercury’s distance from the sun. The estimated surface temperature of this smoldering planet, at more than 800 degrees Fahrenheit (700 degrees Kelvin), would be hot enough to melt the zinc in a penny. Kepler-37c and Kepler-37d, orbit every 21 days and 40 days, respectively.
Some thoughts by Alan Stern on a better way to name exoplanets.
Some thoughts by Alan Stern on a better way to name exoplanets.
Some thoughts by Alan Stern on a better way to name exoplanets.
Even as the Kepler mission struggles to survive, the science team has released its entire database of exoplanets candidates to the public.
Even as the Kepler mission struggles to survive, the science team has released its entire database of exoplanet candidates to the public.
Even as the Kepler mission struggles to survive, the science team has released its entire database of exoplanet candidates to the public.
The Kepler science team today revealed an additional 461 candidate exoplanets, with four being less than twice Earth’s size and in the habitable zone.
Worlds without end: The Kepler science team today revealed an additional 461 candidate exoplanets, with four being less than twice Earth’s size and in the habitable zone.
Since the last Kepler catalog was released in February 2012, the number of candidates discovered in the Kepler data has increased by 20 percent and now totals 2,740 potential planets orbiting 2,036 stars. The most dramatic increases are seen in the number of Earth-size and super Earth-size candidates discovered, which grew by 43 and 21 percent respectively. The new data increases the number of stars discovered to have more than one planet candidate from 365 to 467. Today, 43 percent of Kepler’s planet candidates are observed to have neighbor planets.
Of these candidates, 105 have so far been confirmed to be exoplanets by other methods.
Note that these Kepler planets are in addition to the fifteen new exoplanets noted in my previous post.
Worlds without end: The Kepler science team today revealed an additional 461 candidate exoplanets, with four being less than twice Earth’s size and in the habitable zone.
Since the last Kepler catalog was released in February 2012, the number of candidates discovered in the Kepler data has increased by 20 percent and now totals 2,740 potential planets orbiting 2,036 stars. The most dramatic increases are seen in the number of Earth-size and super Earth-size candidates discovered, which grew by 43 and 21 percent respectively. The new data increases the number of stars discovered to have more than one planet candidate from 365 to 467. Today, 43 percent of Kepler’s planet candidates are observed to have neighbor planets.
Of these candidates, 105 have so far been confirmed to be exoplanets by other methods.
Note that these Kepler planets are in addition to the fifteen new exoplanets noted in my previous post.
Fifteen more exoplanets found orbiting their stars in the habitable zone.
Fifteen more exoplanets have been found, orbiting their stars in the habitable zone.
Fifteen more exoplanets have been found, orbiting their stars in the habitable zone.
Using data from a solar system detected by the Kepler space telescope, astronomers now extrapolate that there are at least as many planets as stars in our galaxy.
Billions and billions! Using data from a solar system detected by the Kepler space telescope, astronomers now extrapolate that there are at least as many planets as stars in our galaxy.
Billions and billions! Using data from a solar system detected by the Kepler space telescope, astronomers now extrapolate that there are at least as many planets as stars in our galaxy.
The Subaru telescope in Hawaii has taken an image of an exoplanet.
The Subaru telescope in Hawaii has taken an image of an exoplanet.
The press release is not clear, but I think this is an image in optical wavelengths, which I also think is a first.
Update: on further research, it turns out the image is in the infrared, not optical. Nonetheless, it is a remarkable image, and will make possible some interesting spectroscopic research.
The Subaru telescope in Hawaii has taken an image of an exoplanet.
The press release is not clear, but I think this is an image in optical wavelengths, which I also think is a first.
Update: on further research, it turns out the image is in the infrared, not optical. Nonetheless, it is a remarkable image, and will make possible some interesting spectroscopic research.
Kepler reveals our Sun might be more variable than we imagine
More exoplanet news: The problems of Kepler.
The article outlines the status — both good and bad — of Kepler in its hunt for Earthlike exoplanets.
I have already reported on Kepler’s failed reaction wheel. It no longer has a backup and needs every reaction wheel it has to keep it pointed in so precise a manner. Thus, the loss of one more wheel will shut the telescope down.
However, I had not been aware that the scientists now need more than twice as much time, eight years instead of three, to do their work, because they have discovered that sunlike stars are far more variable than expected. To quote the article,
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A planet with four suns, found by amateurs.
A planet with four suns, found by amateurs.
A planet with four suns, found by amateurs.
A super Earth, made of diamonds
A super Earth, made of diamonds.
Astronomers also thought 55 Cancri e contained a substantial amount of super-heated water, based on the assumption that its chemical makeup was similar to Earth’s, Madhusudhan said. But the new research suggests the planet has no water at all, and appears to be composed primarily of carbon (as graphite and diamond), iron, silicon carbide, and, possibly, some silicates. The study estimates that at least a third of the planet’s mass — the equivalent of about three Earth masses — could be diamond. “By contrast, Earth’s interior is rich in oxygen, but extremely poor in carbon — less than a part in thousand by mass,” says co-author and Yale geophysicist Kanani Lee.
A super Earth, made of diamonds.
Astronomers also thought 55 Cancri e contained a substantial amount of super-heated water, based on the assumption that its chemical makeup was similar to Earth’s, Madhusudhan said. But the new research suggests the planet has no water at all, and appears to be composed primarily of carbon (as graphite and diamond), iron, silicon carbide, and, possibly, some silicates. The study estimates that at least a third of the planet’s mass — the equivalent of about three Earth masses — could be diamond. “By contrast, Earth’s interior is rich in oxygen, but extremely poor in carbon — less than a part in thousand by mass,” says co-author and Yale geophysicist Kanani Lee.
Astronomers have discovered the first exoplanets to be found inside an open star cluster.
Planets without end: Astronomers have discovered the first exoplanets to be found inside an open star cluster that are orbiting sun-like stars.
Planets without end: Astronomers have discovered the first exoplanets to be found inside an open star cluster that are orbiting sun-like stars.
New computer models now suggest that the the habitable zone for life is far larger than previously estimated.
New computer models now suggest that the the habitable zone for life is far larger than previously estimated.
New computer models now suggest that the the habitable zone for life is far larger than previously estimated.
Another planet has been found in the habitable zone
Planets without end: Another planet has been found in the habitable zone.
Gliese 163c could have a size between 1.8 to 2.4 Earth radii, depending if it is composed mostly of rock or water, respectively. It receives on average 40% more light from its parent star than Earth from the Sun, making it hotter. In comparison, Venus receives 90% more light from the Sun than Earth. We do not know the properties of the atmosphere of Gliese 163c but, if we assume that it is a scaled up version of Earth’s atmosphere, then its surface temperature might be around 60°C [140°F]. Most complex life on Earth (plants, animals, and even humans) are not able to survive at temperatures above 50°C [122°F], however, plenty of extremophilic microbial life forms can thrive at those temperatures or higher.
Planets without end: Another planet has been found in the habitable zone.
Gliese 163c could have a size between 1.8 to 2.4 Earth radii, depending if it is composed mostly of rock or water, respectively. It receives on average 40% more light from its parent star than Earth from the Sun, making it hotter. In comparison, Venus receives 90% more light from the Sun than Earth. We do not know the properties of the atmosphere of Gliese 163c but, if we assume that it is a scaled up version of Earth’s atmosphere, then its surface temperature might be around 60°C [140°F]. Most complex life on Earth (plants, animals, and even humans) are not able to survive at temperatures above 50°C [122°F], however, plenty of extremophilic microbial life forms can thrive at those temperatures or higher.
A solar system with two suns.
Planets without end: A solar system with two suns.
Kepler had previously found two planets orbiting two different binary stars. Here, the space telescope has found a binary star which has its own solar system of two planets.
Planets without end: A solar system with two suns.
Kepler had previously found two planets orbiting two different binary stars. Here, the space telescope has found a binary star which has its own solar system of two planets.
Astronomers have now confirmed 41 new exoplanets, first pinpointed by the Kepler space telescope
Astronomers have now confirmed 41 new exoplanets, first pinpointed by the Kepler space telescope.
One paper, by Jiwei Xie at the University of Toronto, confirms 24 new planets in 12 systems. Another study, by Steffen and his colleagues, confirms 27 planets in 13 systems. Five of the systems, and 10 of the planets, are the same in both papers. All in all, the new research adds 20 new planetary systems to the 47 that Kepler had previously confirmed, marking a more than 40 percent increase.
Among the Kepler candidates are five Earth-sized planets in the habitable zone, according to the vidoe at the link. However, this announcement does not tell us if any of those candidates were confirmed by these two papers.
Astronomers have now confirmed 41 new exoplanets, first pinpointed by the Kepler space telescope.
One paper, by Jiwei Xie at the University of Toronto, confirms 24 new planets in 12 systems. Another study, by Steffen and his colleagues, confirms 27 planets in 13 systems. Five of the systems, and 10 of the planets, are the same in both papers. All in all, the new research adds 20 new planetary systems to the 47 that Kepler had previously confirmed, marking a more than 40 percent increase.
Among the Kepler candidates are five Earth-sized planets in the habitable zone, according to the vidoe at the link. However, this announcement does not tell us if any of those candidates were confirmed by these two papers.
The Earth destroyed repeatedly, in the name of science.
The Earth destroyed repeatedly, in the name of science.
The Earth destroyed repeatedly, in the name of science.
One of Kepler’s reaction wheels — used to orient the space telescope — has failed.
Bad news: One of Kepler’s four reaction wheels — used to orient the space telescope — has failed.
Kepler only needs three wheels to function – one to control the probe’s motion along each axis – and the probe resumed its observations on 20 July. “Kepler is functioning very well on three reaction wheels,” says mission manager Roger Hunter of NASA’s Ames Research Center in Moffett Field, California. If the glitch can’t be fixed, though, Kepler will be left without a backup wheel. “This is reducing the odds of making the mission go as long as we can,” says Kepler chief scientist William Borucki of NASA Ames, who doubts that Kepler could point accurately enough to look for transiting planets if reduced to two reaction wheels. “It was a disappointing surprise to find this wheel stopped so early.”
Bad news: One of Kepler’s four reaction wheels — used to orient the space telescope — has failed.
Kepler only needs three wheels to function – one to control the probe’s motion along each axis – and the probe resumed its observations on 20 July. “Kepler is functioning very well on three reaction wheels,” says mission manager Roger Hunter of NASA’s Ames Research Center in Moffett Field, California. If the glitch can’t be fixed, though, Kepler will be left without a backup wheel. “This is reducing the odds of making the mission go as long as we can,” says Kepler chief scientist William Borucki of NASA Ames, who doubts that Kepler could point accurately enough to look for transiting planets if reduced to two reaction wheels. “It was a disappointing surprise to find this wheel stopped so early.”
Two exoplanets in a tight orbital dance.
Two exoplanets in a tight orbital dance.
“These are the closest two planets to one another that have ever been found,” Agol said. “The bigger planet is pushing the smaller planet around more, so the smaller planet was harder to find.”
Orbiting a star in the Cygnus constellation referred to as Kepler-36a, the planets are designated Kepler-36b and Kepler-36c. Planet b is a rocky planet like Earth, though 4.5 times more massive and with a radius 1.5 times greater. Kepler-36c, which could be either gaseous like Jupiter or watery, is 8.1 times more massive than Earth and has a radius 3.7 times greater.
But wait, there’s more!
The fact that the two planets are so close to each other and exhibit specific orbital patterns allowed the scientists to make fairly precise estimates of each planet’s characteristics, based on their gravitational effects on each other and the resulting variations in the orbits. To date, this is the best-characterized system with small planets, the researchers said.
They believe the smaller planet is 30 percent iron, less than 1 percent atmospheric hydrogen and helium and probably no more than 15 percent water. The larger planet, on the other hand, likely has a rocky core surrounded by a substantial amount of atmospheric hydrogen and helium.
Two exoplanets in a tight orbital dance.
“These are the closest two planets to one another that have ever been found,” Agol said. “The bigger planet is pushing the smaller planet around more, so the smaller planet was harder to find.”
Orbiting a star in the Cygnus constellation referred to as Kepler-36a, the planets are designated Kepler-36b and Kepler-36c. Planet b is a rocky planet like Earth, though 4.5 times more massive and with a radius 1.5 times greater. Kepler-36c, which could be either gaseous like Jupiter or watery, is 8.1 times more massive than Earth and has a radius 3.7 times greater.
But wait, there’s more!
The fact that the two planets are so close to each other and exhibit specific orbital patterns allowed the scientists to make fairly precise estimates of each planet’s characteristics, based on their gravitational effects on each other and the resulting variations in the orbits. To date, this is the best-characterized system with small planets, the researchers said.
They believe the smaller planet is 30 percent iron, less than 1 percent atmospheric hydrogen and helium and probably no more than 15 percent water. The larger planet, on the other hand, likely has a rocky core surrounded by a substantial amount of atmospheric hydrogen and helium.
Watching the transit of Venus – from Saturn
Watching the transit of Venus – from Saturn.
Watching the transit of Venus – from Saturn.
The transit of Venus tomorrow.
An overview of the transit of Venus tomorrow.
An overview of the transit of Venus tomorrow.
One astronomer has found that the habitable zone around some smaller stars is smaller than first calculated because of tidal heating.
One astronomer has found that the inner edge of the habitable zone around some dwarf stars is smaller than first calculated because tidal forces overheat planets close to the star.
Then again, this heating might expand the habitable zone in other directions. Stars might overheat when close to the star, but get a boost of needed heat when they would normally be too far away.
One astronomer has found that the inner edge of the habitable zone around some dwarf stars is smaller than first calculated because tidal forces overheat planets close to the star.
Then again, this heating might expand the habitable zone in other directions. Stars might overheat when close to the star, but get a boost of needed heat when they would normally be too far away.