THE SPITZER MICROLENSING PROGRAM AS A PROBE FOR GLOBULAR CLUSTER PLANETS: ANALYSIS OF OGLE-2015-BLG-0448

Journal Article · Fri May 20 04:00:00 EDT 2016 · Astrophysical Journal

DOI:https://doi.org/10.3847/0004-637X/823/1/63· OSTI ID:22862906

Poleski, Radosław; Zhu, Wei; Gould, Andrew ^[1]; Christie, Grant W. ^[2]; Udalski, Andrzej; Szymański, M. K.; Soszyński, I.; Pietrzyński, G.; Wyrzykowski, Ł.; Ulaczyk, K.; Pietrukowicz, P.; Kozłowski, Szymon; Skowron, J.; Mróz, P.; Pawlak, M. ^[3]; Bachelet, Etienne ^[4]; Skottfelt, Jesper ^[5]; Novati, Sebastiano Calchi; Beichman, C. ^[6]; others, and

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1. Department of Astronomy, Ohio State University, 140 West 18th Avenue, Columbus, OH 43210 (United States)
2. Auckland Observatory, Auckland (New Zealand)
3. Warsaw University Observatory, Al. Ujazdowskie 4, 00-478 Warszawa (Poland)
4. Las Cumbres Observatory Global Telescope Network, 6740 Cortona Drive, Suite 102, Goleta, CA 93117 (United States)
5. Centre for Electronic Imaging, Department of Physical Sciences, The Open University, Milton Keynes MK7 6AA (United Kingdom)
6. NASA Exoplanet Science Institute, MS 100-22, California Institute of Technology, Pasadena, CA 91125 (United States)

The microlensing event OGLE-2015-BLG-0448 was observed by Spitzer and lay within the tidal radius of the globular cluster NGC 6558. The event had moderate magnification and was intensively observed, hence it had the potential to probe the distribution of planets in globular clusters. We measure the proper motion of NGC 6558 (μ{sub cl}(N,E)=(+0.36±0.10,+1.42±0.10) mas yr{sup −1}) as well as the source and show that the lens is not a cluster member. Even though this particular event does not probe the distribution of planets in globular clusters, other potential cluster lens events can be verified using our methodology. Additionally, we find that microlens parallax measured using Optical Gravitational Lens Experiment (OGLE) photometry is consistent with the value found based on the light curve displacement between the Earth and Spitzer.

• OSTI ID: 22862906
• Journal Information: Astrophysical Journal, Journal Name: Astrophysical Journal Journal Issue: 1 Vol. 823; ISSN ASJOAB; ISSN 0004-637X
• Country of Publication: United States
• Language: English

Related Subjects

79 ASTRONOMY AND ASTROPHYSICS
DETECTION
DISTRIBUTION
GRAVITATIONAL LENSES
PHOTOMETRY
PLANETS
PROPER MOTION
SATELLITES