GRANTS

Stellar Pulsation, space photometry, exoplanets (SPEX)


PD-116175: Photometric applications in the K2 mission (2016-2018)

PI: László Molnár


Summary:

The Kepler space telescope has transformed our understanding of exoplanets and stellar astrophysics. Collecting photometric data for four years quasi-continuously, at micromagnitude precision was the key to its success. The loss of two reaction wheels, however, put the whole mission in jeopardy. Since then, Kepler observes in shorter campaigns in the K2 mission along the Ecliptic where the effects of solar radiation pressure can be minimized.

The new campaigns opened the possibilites to observe new fields and new types of objects, keeping Kepler a defining space telescope of the coming years. However, the pixel data provided by the K2 mission require more extensive and careful processing into light curves to approach the exquisite precision of the original mission. My work will make it possible to exploit the unique capabilities of Kepler at new fields of research. I focus on three areas:

  • Photometry of moving objects. Numerous asteroids and a few larger Trans-Neptun Objects are observable along the Ecliptic and their light variations are detectable with the proper methods.
  • Photometry of extremely faint objects. Kepler will cover some nearby dwarf galaxies where faint pulsating variable stars can be identified. Their detection pushes the limits of the space telescope but it would also extend the reach of Kepler beyond the Milky Way.
  • Photometry of large-amplitude variables. Pulsating variable stars show intense light variations that require special methods to handle, but these data could be then directly compared to the extragalactic populations.

Project no. 116175 has been implemented with the support provided from the National Research, Development and Innovation Fund of Hungary, financed under the (former) OTKA PD postdoctoral funding scheme.


Selected results and publications:

  1. Molnár, L.; Pál, A.; Sárneczky, K.; Szabó, R.; Vinkó, J.; Szabó, Gy. M.; Kiss, Cs.; Hanyecz, O.; Marton, G.; Kiss, L. L.: Main-belt asteroids in the K2 Uranus field, 2018, accepted in ApJS
  2. Farkas-Takács, A.; Kiss, Cs.; Pál, A.; Molnár, L.; Szabó, Gy. M.; Hanyecz, O.; Sárneczky, K.; Szabó, R.; Marton, G.; Mommert, M.; Szakáts, R.; Müller, T.; Kiss, L. L.: Properties of the irregular satellite system around Uranus inferred from K2, Herschel and Spitzer observations, 2017, AJ, 154, 119
  3. Molnár, L.; Derekas, A.; Szabó, R.; Matthews, J. M.; Cameron, C.; Moffat, A. F. J.; Richardson, N. D.; Csák, B.; Dózsa, Á.; Reed, P.; Szabados, L.; Heathcote, B.; Bohlsen, T.; Cacella, P.; Luckas, P.; Sódor, Á.; Skarka, M.; Szabó, Gy. M.; Plachy, E.; Kovács, J.; Evans, N. R.; Kolenberg, K.; Collins, K. A.; Pepper, J.; Stassun, K. G.; Rodriguez, J. E.; Siverd, R. J.; Henden, A.; Mankiewicz, L.; Żarnecki, A. F.; Cwiek, A.; Sokolowski, M.; Pál, A.; Guenther, D. B.; Kuschnig, R.; Rowe, J.; Rucinski, S. M.; Sasselov, D.; Weiss, W. W.: V473 Lyr, a modulated, period-doubled Cepheid, and U TrA, a double-mode Cepheid observed by MOST, 2017, MNRAS, 466, 4009
  4. Gaia Collaboration: Gaia Data Release 1. Testing the parallaxes with local Cepheids and RR Lyrae stars, 2017, A&A, 605, 59
  5. Molnár, L., Pál, A., Plachy, E.: Cepheids with the eyes of photometric space telescopes, Proceedings of the 22nd Los Alamos Stellar Pulsation Conference, 2017, EpJ WoC, 152, 02004
  6. Szabó, Gy. M.; Pál, A.; Kiss, Cs.; Kiss, L. L.; Molnár, L.; Hanyecz, O.; Plachy, E.; Sárneczky, K.; Szabó, R.: The heart of the swarm: K2 photometry and rotational characteristics of 56 Jovian Trojan asteroids, 2017, A&A, 599, 44
  7. Derekas, A.; Plachy, E.; Molnár, L.; Sódor, Á.; Benkõ, J. M.; Szabados, L.; Bognár, Zs.; Csák, B.; Szabó, Gy. M.; Szabó, R.; Pál, A. The Kepler Cepheid V1154 Cyg revisited: light curve modulation and detection of granulation, 2017, MNRAS, 464, 1553
  8. Szabó, R.; Pál, A.; Sárneczky, K.; Szabó, Gy. M.; Molnár, L.; Kiss, L. L.; Hanyecz, O.; Plachy, E.; Kiss, Cs.: Uninterrupted optical light curves of main-belt asteroids from the K2 Mission, 2016, A&A, 596, 40
  9. Pál, A.; Müller, T. G.; Molnár, L.; Szabó, R.; Szabó, M. Gy.; Sárneczky, K.; Kiss, L. L.: Large size and slow rotation of the trans-Neptunian object (225088) 2007 OR10 discovered from Herschel and K2 observations, 2016, AJ, 151, 117

Selected talks:

  1. The RR Lyrae 2017 Conference - Revival of Classical Pulsators, 2017. 09. 17-21., Niepolomice (PL) - invited talk: "Letters from the revolution: how are space telescopes changing our views of stars"
  2. Kepler & K2 Science Conference IV, 2017.06.19.23., NASA Ames Research Center, Moffett Field, CA (USA) contributed talk: "The K2 RR Lyrae and Cepheid Survey: Hunting for pulsating variables near and far"
  3. 22nd Los Alamos Stellar Pulsation Conference Series Meeting - wide-field variability surveys: a 21st-century perspective, 2016. 11. 28-12.02., San Pedro de Atacama (CL) - contributed talk: "Cepheid in the eyes of photometric space telescopes"
  4. 48th Conference of Variable Star Research, 2016. 11. 11-13., Prague (CZ) - invited talk: "The Keplerian revolution of variable stars"

Some popular science articles, public lectures, interviews: