May 11, 2016
NASA will host a news teleconference at 1 p.m. EDT Tuesday, May 10 to announce the latest discoveries made by its planet-hunting mission, the Kepler Space Telescope.
The briefing participants are:
★ Paul Hertz, Astrophysics Division director at NASA Headquarters in Washington
★ Timothy Morton, associate research scholar at Princeton University in New Jersey
★ Natalie Batalha, Kepler mission scientist at NASA's Ames Research Center in Moffett Field, California
★ Charlie Sobeck, Kepler/K2 mission manager at Ames
NASA Media Advisory
The research paper these findings are based on as published by The Astrophysical Journal on May 10, 2016: False Positive Probabilities For All Kepler Objects Of Interest: 1284 Newly Validated Planets And 428 Likely False Positives (Morton et al, 2016).
Video: Kepler measures the brightness of stars. The data will look like an EKG showing the heart beat. Whenever a planet passes in front of its parent star as viewed from the spacecraft, a tiny pulse or beat is produced. From the repeated beats we can detect and verify the existence of Earth-size planets and learn about the orbit and size of the planet.
Figure 1: The histogram shows the number of planet discoveries by year for more than the past two decades of the exoplanet search. The blue bar shows previous non-Kepler planet discoveries, the light blue bar shows previous Kepler planet discoveries, the orange bar displays the 1,284 new validated planets.
Figure 2: Kepler's candidates require verification to determine if they are actual planets and not another object, such as a small star, mimicking a planet.
Figure 3: Since the discovery of the first planets outside our solar system more than two decades ago, researchers have resorted to a laborious, one-by-one process of verifying suspected planets. These follow-up observations are often time and resource intensive.
Figure 4: Kepler candidate planets (orange) are smaller and orbit fainter stars than transiting planets detected by ground-based observatories (blue).
Figure 5: A new statistical validation technique enables researchers to quantify the probability that any given candidate signal is in fact caused by a planet, without requiring any follow-up observations. This technique uses two different kinds of simulations-- both simulations of the detailed shapes of transit signals caused by both planets and objects, such as a star, masquerading as planets (left diagram), and also simulations of how common imposters are expected to be in the Milky Way galaxy (right diagram). Combining these two different kinds of information gives scientists a reliability score between zero and one for each candidate. Candidates with reliability greater than 99 percent are call “validated planets.”
Figure 6: The pie chart illustrates the results of a statistical analysis performed on 4,302 potential planets from the Kepler mission’s July 2015 planet candidate catalog. For 1,284 of the candidates (orange), the probability of being a planet is greater than 99 percent – the minimum required to earn the status of “planet.” An additional 1,327 candidates (dark grey) are more likely than not to be actual planets, but they do not meet the 99 percent threshold and will require additional study. The remaining 707 candidates (light grey) are more likely to be some other astrophysical phenomena. This analysis also revalidated 984 candidates (blue) that have previously been verified by other techniques.
Figure 7: Kepler was pointed at the patch of sky near the Lyra and Cygnus constellations. The yellow portion represents Kepler’s field-of-view.
Figure 8: The Arc of Discovery artistic concept features NASA's astrophysics missions searching for signs of life beyond Earth.
Figure 9: The histogram shows the number of planets by size for all known exoplanets. The blue bars on the histogram represent all previously verified exoplanets by size. The orange bars on the histogram represent Kepler's 1,284 newly validated planets announcement on May 10, 2016
Figure 10: Since Kepler launched in 2009, 21 planets less than twice the size of Earth have been discovered in the habitable zones of their stars. The orange spheres represent the nine newly validated planets announcement on May 10, 2016. The blue disks represent the 12 previous known planets. These planets are plotted relative to the temperature of their star and with respect to the amount of energy received from their star in their orbit in Earth units. The sizes of the exoplanets indicate the sizes relative to one another. The images of Earth, Venus and Mars are placed on this diagram for reference. The light and dark green shaded regions indicate the conservative and optimistic habitable zone.
Figure 11: The Kepler mission completed observations in May 2013, and will closeout its remaining analyses in September 2017. The Kepler Spacecraft continues to make astronomical observations as the re-purposed K2 mission.