We report the discovery of a transiting, R sub(p) = 4.347 + or - 0.099R sub(+ in circle), circumbinary planet (CBP) orbiting the Kepler K + M eclipsing binary (EB) system KIC 12351927 (Kepler-413) ...every ~66 days on an eccentric orbit with a sub(p) = 0.355+ or -0.002 AU, e sub(p) = 0.118+ or -0.002. The orbital plane of the EB is slightly inclined to the line of sight (i sub(EB) = 87degrees.33 + or - 0degrees.06), while that of the planet is inclined by ~2degrees.5 to the binary plane at the reference epoch. Orbital precession with a period of ~11 yr causes the inclination of the latter to the sky plane to continuously change. As a result, the planet often fails to transit the primary star at inferior conjunction, causing stretches of hundreds of days with no transits (corresponding to multiple planetary orbital periods).
We present DOHA, a new algorithm for cotrending photometric light curves obtained by transiting exoplanet surveys. The algorithm employs a novel approach to the traditional 'differential photometry' ...technique, by selecting the most suitable comparison star for each target light curve, using a two-step correlation search. Extensive tests on real data reveal that DOHA corrects both intra-night variations and long-term systematics affecting the data. Statistical studies conducted on a sample of ~9500 light curves from the Qatar Exoplanet Survey reveal that DOHA-corrected light curves show an rms improvement of a factor of ~2, compared to the raw light curves. In addition, we show that the transit detection probability in our sample can increase considerably, even up to a factor of 7, after applying DOHA.
L' and M' Photometry of Ultracool Dwarfs Golimowski, D. A; Leggett, S. K; Marley, M. S ...
The Astronomical journal,
06/2004, Volume:
127, Issue:
6
Journal Article
The color-magnitude relation has been determined for the RDCS J0910+5422 cluster of galaxies at redshift z = 1.106. Cluster members were selected from the Hubble Space Telescope Advanced Camera for ...Surveys (HST ACS) images, combined with ground-based near-IR imaging and optical spectroscopy. The observed early-type color-magnitude relation (CMR) in i' sub(775) - z sub(850) versus z sub(850) shows an intrinsic scatter in color of 0.060 c 0.009 mag, within 1' from the cluster X-ray emission center. Both the elliptical and the S0 galaxies show small scatter about the CMR of 0.042 c 0.010 and 0.044 c 0.020 mag, respectively. From the scatter about the CMR, a mean luminosity-weighted age super( )> 3.3 Gyr (z sub(f) - 3) is derived for the elliptical galaxies, assuming a simple stellar population modeling (single-burst solar metallicity). Strikingly, the S0 galaxies in RDCS J0910+5422 are systematically bluer in i sub(775) - z sub(850), by 0.07 c 0.02 mag, than the ellipticals. The ellipticity distribution as a function of color indicates that the face-on S0s in this particular cluster have likely been classified as elliptical Thus, if anything, the offset in color between the elliptical and S0 populations may be even more significant. The color offset between S0 and E galaxies corresponds to an age difference of -1 Gyr for a single-burst solar-metallicity model. A solar-metallicity model with an exponential decay in star formation will reproduce the offset for an age of 3.5 Gyr; i.e., the S0s have evolved gradually from star-forming progenitors. The early-type population in this cluster appears to be still forming. The blue early-type disk galaxies in RDCS J0910+5422 likely represent the direct progenitors of the more evolved S0s that follow the same red sequence as elliptical galaxies in other clusters. Thirteen red galaxy pairs are observed, and the galaxies associated in pairs constitute 640% of the CMR galaxies in this cluster.
We present deep HST ACS observations in unk toward the z = 4.1 radio galaxy TN J1338-1942 and its overdensity of >30 spectroscopically confirmed Ly alpha emitters (LAEs). We select 66 g sub(475) band ...dropouts to unk = 27, 6 of which are also LAEs. Although our color-color selection results in a relatively broad redshift range centered on z - 4.1, the field of TN J1338-1942 is richer than the average field at the >5 sigma significance, based on a comparison with GOODS. The angular distribution is filamentary with about half of the objects clustered near the radio galaxy, and a small, excess signal (2 sigma ) in the projected pair counts at separations of theta < 10" is interpreted as being due to physical pairs. The LAEs are young (a few times 10 super(7) yr), small ((r sub(bl)) unk 0.13") galaxies, and we derive a mean stellar mass of similar to 10 super(8)-10 super(9) M unk based on a stacked K sub(s) band image. We determine star formation rates, sizes, morphologies, and color-magnitude relations of the g sub(475) -dropouts and find no evidence for a difference between galaxies near TN J1338-1942 and in the field. We conclude that environmental trends as observed in clusters at much lower redshift are either not yet present or washed out by the relatively broad selection in redshift. The large galaxy overdensity, its corresponding mass overdensity, and the subclustering at the approximate redshift of TN J1338-1942 suggest the assemblage of a >10 super(14) M unk structure, confirming that it is possible to find and study cluster progenitors in the linear regime at z unk 4.
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