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Charles A Beichman - One of the best experts on this subject based on the ideXlab platform.
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spitzer observations confirm and rescue the habitable zone super earth k2 18b for future characterization
The Astrophysical Journal, 2017Co-Authors: Bjorn Benneke, Heather A Knutson, Ian J M Crossfield, Courtney D Dressing, M W Werner, Erik A Petigura, Joshua E Schlieder, John H Livingston, Charles A BeichmanAbstract:The recent detections of two transit events attributed to the super-Earth candidate K2-18b have provided the unprecedented prospect of spectroscopically studying a habitable-zone planet outside the solar system. Orbiting a nearby M2.5 dwarf and receiving virtually the same stellar insolation as Earth, K2-18b would be a prime candidate for the first detailed atmospheric characterization of a habitable-zone exoplanet using the Hubble Space Telescope (HST)and James Webb Space Telescope (JWST). Here, we report the detection of a third transit of K2-18b near the predicted transit time using the Spitzer Space Telescope. The Spitzer detection demonstrates the periodic nature of the two transit events discovered by K2, confirming that K2-18 is indeed orbited by a super-Earth in a 33 day orbit, ruling out the alternative scenario of two similarly sized, long-period planets transiting only once within the 75 day Kepler Space Telescope (K2) observation. We also find, however, that the transit event detected by Spitzer occurred 1.85 hr ($7\sigma $) before the predicted transit time. Our joint analysis of the Spitzer and K2 photometry reveals that this early occurrence of the transit is not caused by transit timing variations, but the result of an inaccurate Ephemeris due to a previously undetected data anomaly in the K2 photometry. We refit the Ephemeris and find that K2-18b would have been lost for future atmospheric characterizations with HST and JWST if we had not secured its Ephemeris shortly after the discovery. We caution that immediate follow-up observations as presented here will also be critical for confirming and securing future planets discovered by the Transiting Exoplanet Survey Satellite (TESS), in particular if only two transit events are covered by the relatively short 27-day TESS campaigns.
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spitzer observations confirm and rescue the habitable zone super earth k2 18b for future characterization
arXiv: Earth and Planetary Astrophysics, 2016Co-Authors: Bjorn Benneke, Heather A Knutson, Ian J M Crossfield, Courtney D Dressing, M W Werner, Erik A Petigura, Joshua E Schlieder, John H Livingston, Charles A BeichmanAbstract:The recent detections of two transit events attributed to the super-Earth candidate K2-18b have provided the unprecedented prospect of spectroscopically studying a habitable-zone planet outside the Solar System. Orbiting a nearby M2.5 dwarf and receiving virtually the same stellar insolation as Earth, K2-18b would be a prime candidate for the first detailed atmospheric characterization of a habitable-zone exoplanet using HST and JWST. Here, we report the detection of a third transit of K2-18b near the predicted transit time using the Spitzer Space Telescope. The Spitzer detection demonstrates the periodic nature of the two transit events discovered by K2, confirming that K2-18 is indeed orbited by a super-Earth in a 33-day orbit and ruling out the alternative scenario of two similarly-sized, long-period planets transiting only once within the 75-day K2 observation. We also find, however, that the transit event detected by Spitzer occurred 1.85 hours (7-sigma) before the predicted transit time. Our joint analysis of the Spitzer and K2 photometry reveals that this early occurrence of the transit is not caused by transit timing variations (TTVs), but the result of an inaccurate K2 Ephemeris due to a previously undetected data anomaly in the K2 photometry likely caused by a cosmic ray hit. We refit the Ephemeris and find that K2-18b would have been lost for future atmospheric characterizations with HST and JWST if we had not secured its Ephemeris shortly after the discovery. We caution that immediate follow-up observations as presented here will also be critical in confirming and securing future planets discovered by TESS, in particular if only two transit events are covered by the relatively short 27-day TESS campaigns.
Ian J M Crossfield - One of the best experts on this subject based on the ideXlab platform.
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spitzer observations confirm and rescue the habitable zone super earth k2 18b for future characterization
The Astrophysical Journal, 2017Co-Authors: Bjorn Benneke, Heather A Knutson, Ian J M Crossfield, Courtney D Dressing, M W Werner, Erik A Petigura, Joshua E Schlieder, John H Livingston, Charles A BeichmanAbstract:The recent detections of two transit events attributed to the super-Earth candidate K2-18b have provided the unprecedented prospect of spectroscopically studying a habitable-zone planet outside the solar system. Orbiting a nearby M2.5 dwarf and receiving virtually the same stellar insolation as Earth, K2-18b would be a prime candidate for the first detailed atmospheric characterization of a habitable-zone exoplanet using the Hubble Space Telescope (HST)and James Webb Space Telescope (JWST). Here, we report the detection of a third transit of K2-18b near the predicted transit time using the Spitzer Space Telescope. The Spitzer detection demonstrates the periodic nature of the two transit events discovered by K2, confirming that K2-18 is indeed orbited by a super-Earth in a 33 day orbit, ruling out the alternative scenario of two similarly sized, long-period planets transiting only once within the 75 day Kepler Space Telescope (K2) observation. We also find, however, that the transit event detected by Spitzer occurred 1.85 hr ($7\sigma $) before the predicted transit time. Our joint analysis of the Spitzer and K2 photometry reveals that this early occurrence of the transit is not caused by transit timing variations, but the result of an inaccurate Ephemeris due to a previously undetected data anomaly in the K2 photometry. We refit the Ephemeris and find that K2-18b would have been lost for future atmospheric characterizations with HST and JWST if we had not secured its Ephemeris shortly after the discovery. We caution that immediate follow-up observations as presented here will also be critical for confirming and securing future planets discovered by the Transiting Exoplanet Survey Satellite (TESS), in particular if only two transit events are covered by the relatively short 27-day TESS campaigns.
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spitzer observations confirm and rescue the habitable zone super earth k2 18b for future characterization
arXiv: Earth and Planetary Astrophysics, 2016Co-Authors: Bjorn Benneke, Heather A Knutson, Ian J M Crossfield, Courtney D Dressing, M W Werner, Erik A Petigura, Joshua E Schlieder, John H Livingston, Charles A BeichmanAbstract:The recent detections of two transit events attributed to the super-Earth candidate K2-18b have provided the unprecedented prospect of spectroscopically studying a habitable-zone planet outside the Solar System. Orbiting a nearby M2.5 dwarf and receiving virtually the same stellar insolation as Earth, K2-18b would be a prime candidate for the first detailed atmospheric characterization of a habitable-zone exoplanet using HST and JWST. Here, we report the detection of a third transit of K2-18b near the predicted transit time using the Spitzer Space Telescope. The Spitzer detection demonstrates the periodic nature of the two transit events discovered by K2, confirming that K2-18 is indeed orbited by a super-Earth in a 33-day orbit and ruling out the alternative scenario of two similarly-sized, long-period planets transiting only once within the 75-day K2 observation. We also find, however, that the transit event detected by Spitzer occurred 1.85 hours (7-sigma) before the predicted transit time. Our joint analysis of the Spitzer and K2 photometry reveals that this early occurrence of the transit is not caused by transit timing variations (TTVs), but the result of an inaccurate K2 Ephemeris due to a previously undetected data anomaly in the K2 photometry likely caused by a cosmic ray hit. We refit the Ephemeris and find that K2-18b would have been lost for future atmospheric characterizations with HST and JWST if we had not secured its Ephemeris shortly after the discovery. We caution that immediate follow-up observations as presented here will also be critical in confirming and securing future planets discovered by TESS, in particular if only two transit events are covered by the relatively short 27-day TESS campaigns.
Bjorn Benneke - One of the best experts on this subject based on the ideXlab platform.
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spitzer observations confirm and rescue the habitable zone super earth k2 18b for future characterization
The Astrophysical Journal, 2017Co-Authors: Bjorn Benneke, Heather A Knutson, Ian J M Crossfield, Courtney D Dressing, M W Werner, Erik A Petigura, Joshua E Schlieder, John H Livingston, Charles A BeichmanAbstract:The recent detections of two transit events attributed to the super-Earth candidate K2-18b have provided the unprecedented prospect of spectroscopically studying a habitable-zone planet outside the solar system. Orbiting a nearby M2.5 dwarf and receiving virtually the same stellar insolation as Earth, K2-18b would be a prime candidate for the first detailed atmospheric characterization of a habitable-zone exoplanet using the Hubble Space Telescope (HST)and James Webb Space Telescope (JWST). Here, we report the detection of a third transit of K2-18b near the predicted transit time using the Spitzer Space Telescope. The Spitzer detection demonstrates the periodic nature of the two transit events discovered by K2, confirming that K2-18 is indeed orbited by a super-Earth in a 33 day orbit, ruling out the alternative scenario of two similarly sized, long-period planets transiting only once within the 75 day Kepler Space Telescope (K2) observation. We also find, however, that the transit event detected by Spitzer occurred 1.85 hr ($7\sigma $) before the predicted transit time. Our joint analysis of the Spitzer and K2 photometry reveals that this early occurrence of the transit is not caused by transit timing variations, but the result of an inaccurate Ephemeris due to a previously undetected data anomaly in the K2 photometry. We refit the Ephemeris and find that K2-18b would have been lost for future atmospheric characterizations with HST and JWST if we had not secured its Ephemeris shortly after the discovery. We caution that immediate follow-up observations as presented here will also be critical for confirming and securing future planets discovered by the Transiting Exoplanet Survey Satellite (TESS), in particular if only two transit events are covered by the relatively short 27-day TESS campaigns.
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spitzer observations confirm and rescue the habitable zone super earth k2 18b for future characterization
arXiv: Earth and Planetary Astrophysics, 2016Co-Authors: Bjorn Benneke, Heather A Knutson, Ian J M Crossfield, Courtney D Dressing, M W Werner, Erik A Petigura, Joshua E Schlieder, John H Livingston, Charles A BeichmanAbstract:The recent detections of two transit events attributed to the super-Earth candidate K2-18b have provided the unprecedented prospect of spectroscopically studying a habitable-zone planet outside the Solar System. Orbiting a nearby M2.5 dwarf and receiving virtually the same stellar insolation as Earth, K2-18b would be a prime candidate for the first detailed atmospheric characterization of a habitable-zone exoplanet using HST and JWST. Here, we report the detection of a third transit of K2-18b near the predicted transit time using the Spitzer Space Telescope. The Spitzer detection demonstrates the periodic nature of the two transit events discovered by K2, confirming that K2-18 is indeed orbited by a super-Earth in a 33-day orbit and ruling out the alternative scenario of two similarly-sized, long-period planets transiting only once within the 75-day K2 observation. We also find, however, that the transit event detected by Spitzer occurred 1.85 hours (7-sigma) before the predicted transit time. Our joint analysis of the Spitzer and K2 photometry reveals that this early occurrence of the transit is not caused by transit timing variations (TTVs), but the result of an inaccurate K2 Ephemeris due to a previously undetected data anomaly in the K2 photometry likely caused by a cosmic ray hit. We refit the Ephemeris and find that K2-18b would have been lost for future atmospheric characterizations with HST and JWST if we had not secured its Ephemeris shortly after the discovery. We caution that immediate follow-up observations as presented here will also be critical in confirming and securing future planets discovered by TESS, in particular if only two transit events are covered by the relatively short 27-day TESS campaigns.
Jeffrey L Coughlin - One of the best experts on this subject based on the ideXlab platform.
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contamination in the kepler field identification of 685 kois as false positives via Ephemeris matching based on q1 q12 data
The Astronomical Journal, 2014Co-Authors: Jeffrey L Coughlin, Susan E Thompson, Stephen T Bryson, Christopher J Burke, Douglas A Caldwell, Jessie L ChristiansenAbstract:The Kepler mission has to date found almost 6000 planetary transit-like signals, utilizing three years of data for over 170,000 stars at extremely high photometric precision. Due to its design, contamination from eclipsing binaries, variable stars, and other transiting planets results in a significant number of these signals being false positives (FPs). This directly affects the determination of the occurrence rate of Earth-like planets in our Galaxy, as well as other planet population statistics. In order to detect as many of these FPs as possible, we perform Ephemeris matching among all transiting planet, eclipsing binary, and variable star sources. We find that 685 Kepler Objects of Interest (KOIs)—12% of all those analyzed—are FPs as a result of contamination, due to 409 unique parent sources. Of these, 118 have not previously been identified by other methods. We estimate that ~35% of KOIs are FPs due to contamination, when performing a first-order correction for observational bias. Comparing single-planet candidate KOIs to multi-planet candidate KOIs, we find an observed FP fraction due to contamination of 16% and 2.4% respectively, bolstering the existing evidence that multi-planet KOIs are significantly less likely to be FPs. We also analyze the parameter distributions of the Ephemeris matches and derive a simple model for the most common type of contamination in the Kepler field. We find that the Ephemeris matching technique is able to identify low signal-to-noise FPs that are difficult to identify with other vetting techniques. We expect FP KOIs to become more frequent when analyzing more quarters of Kepler data, and note that many of them will not be able to be identified based on Kepler data alone.
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contamination in the kepler field identification of 685 kois as false positives via Ephemeris matching based on q1 q12 data
arXiv: Instrumentation and Methods for Astrophysics, 2014Co-Authors: Jeffrey L Coughlin, Susan E Thompson, Stephen T Bryson, Christopher J Burke, Douglas A Caldwell, Jessie L ChristiansenAbstract:The Kepler mission has to date found almost 6,000 planetary transit-like signals, utilizing three years of data for over 170,000 stars at extremely high photometric precision. Due to its design, contamination from eclipsing binaries, variable stars, and other transiting planets results in a significant number of these signals being false positives. This directly affects the determination of the occurrence rate of Earth-like planets in our Galaxy, as well as other planet population statistics. In order to detect as many of these false positives as possible, we perform Ephemeris matching among all transiting planet, eclipsing binary, and variable star sources. We find that 685 Kepler Objects of Interest - 12% of all those analyzed - are false positives as a result of contamination, due to 409 unique parent sources. Of these, 118 have not previously been identified by other methods. We estimate that ~35% of KOIs are false positives due to contamination, when performing a first-order correction for observational bias. Comparing single-planet candidate KOIs to multi-planet candidate KOIs, we find an observed false positive fraction due to contamination of 16% and 2.4% respectively, bolstering the existing evidence that multi-planet KOIs are significantly less likely to be false positives. We also analyze the parameter distributions of the Ephemeris matches and derive a simple model for the most common type of contamination in the Kepler field. We find that the Ephemeris matching technique is able to identify low signal-to-noise false positives that are difficult to identify with other vetting techniques. We expect false positive KOIs to become more frequent when analyzing more quarters of Kepler data, and note that many of them will not be able to be identified based on Kepler data alone.
Heather A Knutson - One of the best experts on this subject based on the ideXlab platform.
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spitzer observations confirm and rescue the habitable zone super earth k2 18b for future characterization
The Astrophysical Journal, 2017Co-Authors: Bjorn Benneke, Heather A Knutson, Ian J M Crossfield, Courtney D Dressing, M W Werner, Erik A Petigura, Joshua E Schlieder, John H Livingston, Charles A BeichmanAbstract:The recent detections of two transit events attributed to the super-Earth candidate K2-18b have provided the unprecedented prospect of spectroscopically studying a habitable-zone planet outside the solar system. Orbiting a nearby M2.5 dwarf and receiving virtually the same stellar insolation as Earth, K2-18b would be a prime candidate for the first detailed atmospheric characterization of a habitable-zone exoplanet using the Hubble Space Telescope (HST)and James Webb Space Telescope (JWST). Here, we report the detection of a third transit of K2-18b near the predicted transit time using the Spitzer Space Telescope. The Spitzer detection demonstrates the periodic nature of the two transit events discovered by K2, confirming that K2-18 is indeed orbited by a super-Earth in a 33 day orbit, ruling out the alternative scenario of two similarly sized, long-period planets transiting only once within the 75 day Kepler Space Telescope (K2) observation. We also find, however, that the transit event detected by Spitzer occurred 1.85 hr ($7\sigma $) before the predicted transit time. Our joint analysis of the Spitzer and K2 photometry reveals that this early occurrence of the transit is not caused by transit timing variations, but the result of an inaccurate Ephemeris due to a previously undetected data anomaly in the K2 photometry. We refit the Ephemeris and find that K2-18b would have been lost for future atmospheric characterizations with HST and JWST if we had not secured its Ephemeris shortly after the discovery. We caution that immediate follow-up observations as presented here will also be critical for confirming and securing future planets discovered by the Transiting Exoplanet Survey Satellite (TESS), in particular if only two transit events are covered by the relatively short 27-day TESS campaigns.
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spitzer observations confirm and rescue the habitable zone super earth k2 18b for future characterization
arXiv: Earth and Planetary Astrophysics, 2016Co-Authors: Bjorn Benneke, Heather A Knutson, Ian J M Crossfield, Courtney D Dressing, M W Werner, Erik A Petigura, Joshua E Schlieder, John H Livingston, Charles A BeichmanAbstract:The recent detections of two transit events attributed to the super-Earth candidate K2-18b have provided the unprecedented prospect of spectroscopically studying a habitable-zone planet outside the Solar System. Orbiting a nearby M2.5 dwarf and receiving virtually the same stellar insolation as Earth, K2-18b would be a prime candidate for the first detailed atmospheric characterization of a habitable-zone exoplanet using HST and JWST. Here, we report the detection of a third transit of K2-18b near the predicted transit time using the Spitzer Space Telescope. The Spitzer detection demonstrates the periodic nature of the two transit events discovered by K2, confirming that K2-18 is indeed orbited by a super-Earth in a 33-day orbit and ruling out the alternative scenario of two similarly-sized, long-period planets transiting only once within the 75-day K2 observation. We also find, however, that the transit event detected by Spitzer occurred 1.85 hours (7-sigma) before the predicted transit time. Our joint analysis of the Spitzer and K2 photometry reveals that this early occurrence of the transit is not caused by transit timing variations (TTVs), but the result of an inaccurate K2 Ephemeris due to a previously undetected data anomaly in the K2 photometry likely caused by a cosmic ray hit. We refit the Ephemeris and find that K2-18b would have been lost for future atmospheric characterizations with HST and JWST if we had not secured its Ephemeris shortly after the discovery. We caution that immediate follow-up observations as presented here will also be critical in confirming and securing future planets discovered by TESS, in particular if only two transit events are covered by the relatively short 27-day TESS campaigns.
