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The Carnegie-Chicago Hubble Program. VII. The Distance to M101 via the Optical Tip of the Red Giant Branch Method
Madore, Barry F.; Freedman, Wendy L.; Beaton, Rachael L. +9 more
The Carnegie-Chicago Hubble Program (CCHP) is building a direct path to the Hubble constant (H 0) using Population II stars as the calibrator of the Type Ia supernova (SN Ia)-based distance scale. This path to calibrate the SNe Ia is independent of the systematics in the traditional Cepheid-based technique. In this paper, we present the…
HD 2685 b: a hot Jupiter orbiting an early F-type star detected by TESS
Henning, Thomas; Vanderburg, Andrew; Latham, David W. +50 more
We report on the confirmation of a transiting giant planet around the relatively hot (Teff = 6801 ± 76 K) star HD 2685, whose transit signal was detected in Sector 1 data of NASA's TESS mission. We confirmed the planetary nature of the transit signal using Doppler velocimetric measurements with CHIRON, CORALIE, and FEROS, as well as usi…
Hi-C 2.1 Observations of Jetlet-like Events at Edges of Solar Magnetic Network Lanes
Tiwari, Sanjiv K.; Winebarger, Amy R.; Warren, Harry P. +15 more
We present high-resolution, high-cadence observations of six, fine-scale, on-disk jet-like events observed by the High-resolution Coronal Imager 2.1 (Hi-C 2.1) during its sounding-rocket flight. We combine the Hi-C 2.1 images with images from the Solar Dynamics Observatory (SDO)/Atmospheric Imaging Assembly (AIA) and the Interface Region Imaging S…
The MASSIVE Survey. XII. Connecting Stellar Populations of Early-type Galaxies to Kinematics and Environment
Ma, Chung-Pei; Greene, Jenny E.; Blakeslee, John P. +6 more
We measure the stellar populations as a function of the radius for 90 early-type galaxies (ETGs) in the MASSIVE survey, a volume-limited integral-field spectroscopic (IFS) galaxy survey targeting all northern-sky ETGs with an absolute K-band magnitude of M K < -25.3 mag or a stellar mass of {M}* ≳ 4× {10}11 {M…
Carbon-rich (DQ) white dwarfs in the Sloan Digital Sky Survey
Kepler, S. O.; Koester, D.
Context. Among the spectroscopically identified white dwarfs, a fraction smaller than 2% have spectra dominated by carbon lines, mainly molecular C2, but also a smaller group dominated by C I and C II lines. These are together called DQ white dwarfs.
Aims: We want to derive atmospheric parameters Teff, log g, and carbon …
An Exo-Kuiper Belt with an Extended Halo around HD 191089 in Scattered Light
Debes, John H.; Schneider, Glenn; Duchêne, Gaspard +70 more
We have obtained Hubble Space Telescope STIS and NICMOS and Gemini/GPI scattered-light images of the HD 191089 debris disk. We identify two spatial components: a ring resembling the Kuiper Belt in radial extent (FWHM ∼ 25 au, centered at ∼46 au) and a halo extending to ∼640 au. We find that the halo is significantly bluer than the ring, consistent…
PDS 70: A Transition Disk Sculpted by a Single Planet
van der Marel, Nienke; Muley, Dhruv; Fung, Jeffrey
The wide, deep cavities of transition disks are often believed to have been hollowed out by nascent planetary systems. PDS 70, a ∼5 Myr old transition disk system in which a multi-Jupiter-mass planet candidate at 22 au coexists with a ∼30 au gas and ∼60 au dust-continuum gap, provides a valuable case study for this hypothesis. Using the PEnGUIn hy…
Dynamical Histories of the Crater II and Hercules Dwarf Galaxies
Simon, Joshua D.; Fu, Sal Wanying; Alarcón Jara, Alex G.
We investigate the possibility that the dwarf galaxies Crater II and Hercules have previously been tidally stripped by the Milky Way. We present Magellan/IMACS spectra of candidate member stars in both objects. We identify 37 members of Crater II, 25 of which have velocity measurements in the literature, and we classify three stars within that sub…
A kilometre-sized Kuiper belt object discovered by stellar occultation using amateur telescopes
Wada, T.; Usui, F.; Ichikawa, K. +7 more
Kuiper belt objects (KBOs) are thought to be remnants of the early Solar System, and their size distribution provides an opportunity to explore the formation and evolution of the outer Solar System1-5. In particular, the size distribution of kilometre-sized (radius = 1-10 km) KBOs represents a signature of initial planetesimal sizes whe…
Extended Main-sequence Turnoffs in the Double Cluster h and χ Persei: The Complex Role of Stellar Rotation
Milone, Antonino P.; Cordoni, Giacomo; Deng, Licai +4 more
Using Gaia Data Release 2 photometry, we report the detection of extended main-sequence turnoff (eMSTO) regions in the color-magnitude diagrams (CMDs) of the ∼14 Myr old double clusters h and χ Persei (NGC 869 and NGC 884). We find that stars with masses below ∼1.3 M ⊙ in both h and χ Persei populate narrow main sequences (MSs), while m…