K2 Supernova Cosmology Experiment

Summary

  • From Dec 2017 through Apr 2018, K2 Campaigns 16 & 17 will be able to monitor >20,000 low-z galaxies to gather a statistical sample of the best supernovae lightcurves ever obtained.
  • K2 will catch the critical first few hours of supernovae, allowing different explosion physics and progenitors to be elucidated.
  • K2 will improve the calibration of Type Ia supernovae for cosmology by determining the key parameters needed for distance fitting.
  • The fields observed will be visible from the ground, enabling simultaneous observations to complement K2’s single-bandpass photometry.
  • Proposals to select and analyze K2 targets are eligible for funding up to $150,000 as part of K2 GO Cycle 5. The Step 1 deadline is Nov 3, 2016. Proposals in all areas of astrophysics and planetary science are encouraged.
  • A workshop will be held at NASA Ames on Feb 14-16, 2017, to help plan the observing and data analysis efforts.

Background

The traditional late start, ground-based observations of typical supernova searches guarantees that most supernovae are found at or past maximum light. Yet there is clearly a tremendous amount of information about the explosion contained in the early phases of the light curve. The 30-min cadence and continuous coverage of K2 observations are providing the best rise-time information ever obtained for thermonuclear supernovae and constrain the shock breakout of core collapse events.

The trigger mechanism for a white dwarf to explode as a Type Ia supernova is unknown. If a mass-losing companion star is present, then when the expanding material from the supernova hits it, extra shock emission will be evident (e.g. Kasen 2010). That emission, occurring in the first several days and dependent on viewing angle, requires early and continual observing of many Type Ia supernovae to clearly define the circumstances of the shock and discover the progenitors of the events. Early rise-time features due to different explosion physics and different progenitors of both Type Ia and core-collapse supernovae can be elucidated if a large sample of supernovae are observed.

Following a call for novel science experiments that can be accomplished during K2's extended mission, feedback was received to carry out a "forward-facing" campaign to enable observations of supernovae and allow simultaneous ground-based spectroscopic observations. The large sample of supernova light curves expected from K2 will improve the calibration of Type Ia supernovae for cosmology by reducing uncertainties in distance measurements. By determining the key parameters needed for distance fitting (light-curve width and maximum luminosity), K2 observations will improve the precision of distances that are used for H0 and constraints on dark energy.

A limitation that K2 supernova scientists have faced is that simultaneous observations from Earth are challenging. They have relied on twilight observations for photometric and spectroscopic characterization. In Campaigns 16 and 17, K2 will execute forward-facing programs. This will allow simultaneous ground-based SN observations to complement K2’s single-bandpass photometry.

K2 Supernova Workshop

The K2 mission will host a Supernova Workshop on Feb 14-16, 2017, at NASA Ames in Mountain View, California. The motivations for this workshop include:

  • provide an opportunity to plan the K2 observations with mission team members;
  • coordinate the simultaneous, ground-based follow-up observations;
  • prepare the data analysis efforts;
  • explore synergies with other science areas that would benefit from the observations.

Dates

The workshop will begin on Tuesday, February 14, at 10am and end on Thursday, February 16, at 5pm.

Format

This will be an unconference-style meeting with a limited number of introductory talks and a strong focus on participant-led breakout sessions. The final day will provide ample time for drafting papers and observing proposals.

Venue

The workshop will take place at the NASA Ames Conference Center (Building 152), in Mountain View, California.

Access to the NASA Ames requires a valid form of ID to be shown at the main gate. Non US-citizens will be required to pick up a badge at the main gate and need to register before January 9th for this reason.

The nearest airport is the San Jose International Airport (SJC). The nearest alternative to SJC is San Francisco International Airport (SFO). We recommend hiring a rental car or using the Uber or Lyft apps for transportation from the airport.

Accommodation

On-site accommodation has been block-booked for this meeting at the NASA Lodge, which offers affordable rooms with private bath, microwave, and refrigerator in one of two buildings:

  • Building 19 offers queen-sized beds with tv and airconditioning at $65/night;
  • Building 583 offers double or twin beds without tv or airconditioning at $55/night.

Bookings need to be made by phone on +1 650 603 7100, mentioning you are a participant of the K2 Supernova Workshop at the conference center. A credit card will be required to make the reservation.

Alternatively, the conference center provides a list of local hotels. Those nearest to Ames are the County Inn and the Hampton Inn & Suites. These options are more expensive but are located closer to downtown Mountain View, which provides ample restaurant options.

Registration

Registration will open soon.

Non-US participants will be required to register by January 9th, 2017.

Organizing Committee

  • Thomas Barclay - K2 GO Office
  • Geert Barentsen - K2 GO Office
  • Knicole Colón - K2 GO Office
  • Jessie Dotson - K2 Project Scientist
  • Mark Messersmith - K2 Business Office Administration / Project Specialist
  • Brad Tucker - KEGS team