The K2 mission has successfully completed its first official set of science observations and the data are on the ground! Campaign 2 observations are now underway.
The team is processing and preparing the data from Campaign 1, which are scheduled to be delivered to the public at the Mikulski Archive for Space Telescopes (MAST) in November. Campaign 1 targets included more than 12,000 stars for exoplanet transit searches, as well as young and old star clusters and galaxies. The latter are being examined for black hole accretion activity or supernovae.
This past spring the team performed an end-to-end shakedown of spacecraft operations and performance in the new two-wheel K2 mode. While this was primarily an engineering test, science observations were made on approximately 8,000 targets, including the open star cluster Messier 35 and the compact open star cluster NGC 2158, both in the constellation Gemini. Coined “Campaign 0,” these data were delivered to the public archive at MAST on Monday, Sept. 8.
The team is now accepting target proposals for Campaigns 4 and 5. The deadline for K2 Cycle-1 Stage-2 Guest Observer proposals is 23:59 p.m. EDT on Sept. 23. For the full schedule of operational milestones see the K2 Mission Timeline.
On Aug. 23, the K2 mission began its second campaign. The Campaign 2 field of view includes the globular star clusters M4 and M80 in the constellation of Scorpius, the very dense star-forming region Rho Ophiuchi, along with 17,000 target stars that can be searched for exoplanets. In mid-October, Comet Siding Spring will be observed for approximately 77 hours as it passes through Kepler’s field of view. Many other NASA missions also will be pointed toward the comet. Mars also passes through the field of view, but is too bright to be observed. The campaign is scheduled to conclude on Nov. 11, and will be our first K2 campaign to go from start to finish without a break in the middle.
Meanwhile, the spacecraft continues to deliver robust performance in its two-wheel K2 mode. In early August, a reassessment of the fuel usage increased the expected life of the spacecraft by 25 percent. At the current burn rate, the onboard fuel reserves are now expected to last until late 2017, and perhaps beyond. And last week the spacecraft weathered the effects of a large solar flare without missing a beat!
To learn more about the K2 mission visit the Kepler Science Center website.
Despite ongoing K2 operations, the bulk of the mission science focus remains on finalizing the data processing and products for the formal Kepler mission. Two more releases of the data processing pipeline are scheduled that will include enhancements to increase the sensitivity to small planets in long-period orbits, similar to Earth, and determine their frequency in the galaxy– Kepler’s primary objective.
The following are highlights of recent research using Kepler data that have been accepted by a peer-review journal:
- Most Sub-Arcsecond Companions of Kepler Exoplanet Candidate Host Stars are Gravitationally Bound (Horch et al., 2014) – This paper finds that about half of the stars hosting planets are actually binary stars. That is, a pair of stars where the planet orbits one of the stars while the other is a bright nighttime spectacle.
- The Variable Sky of Deep Synoptic Surveys (Ridgway et al., 2014) – Using Kepler light curves to understand how stars and galaxies vary, this paper extends these results to the entire sky to estimate the science yield that will come from the Large Synoptic Survey Telescope and the Gaia space mission, both to undertake all-sky surveys within the next decade.
- On the Frequency of Potential Venus Analogs from Kepler Data (Kane et al., 2014) – The sensitivity of Kepler data to Earth-sized planets allows us to investigate the frequency of Venus analogs since these planets are similar in size; however, Venus has a runaway greenhouse atmosphere. By using climate models to calculate the distances from a star where a runaway greenhouse would occur, this paper defines a “Venus Zone” for potential Venus analogs and estimates that almost half of sun-like stars harbor an analog to our sister planet.