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  • Re-examining the Radial Distributions of M13 Multiple Populations
    Astron. J. (IF 5.838) Pub Date : 2020-10-14
    Jason P. Smolinski, Willem B. Hoogendam, Alex J. Van Kooten, Peyton Benac, and Zachary J. Bruce

    We seek to resolve the tension in the literature regarding the presence of radially segregated multiple populations in the Galactic globular cluster M13. Previous studies of this nearby cluster have presented discordant results about the degree of dynamical mixing in M13's inner region. Using ground-based ( UBVI ) photometry, we show that cumulative radial distributions of stars on the blue and red

    更新日期:2020-10-16
  • On the Orbital Elements of the Two-body Problem with Slowly Decreasing Mass: The Gyldén–Mestchersky Cases
    Astron. J. (IF 5.838) Pub Date : 2020-10-14
    Alberto Abad, Manuel Calvo, José A. Docobo, and Antonio Elipe

    We study the dynamics of two-body problems with gravitational parameters μ = μ ( t ) decreasing with the time. In particular we focus our attention on the behavior of the orbital elements in the first two Gyldén–Mestchersky cases: in the first case (GM-I) ##IMG## [http://ej.iop.org/images/1538-3881/160/5/203/ajabb4e4ieqn1.gif] {$\mu {(t)={\mu }_{0}(1+\alpha t)}^{-1}$} , where μ 0 is the constant initial

    更新日期:2020-10-16
  • A Novel Machine Learning Approach to Disentangle Multitemperature Regions in Galaxy Clusters
    Astron. J. (IF 5.838) Pub Date : 2020-10-14
    Carter Rhea, Julie Hlavacek-Larrondo, Laurence Perreault-Levasseur, Marie-Lou Gendron-Marsolais, and Ralph Kraft

    The hot intracluster medium (ICM) surrounding the heart of galaxy clusters is a complex medium that comprises various emitting components. Although previous studies of nearby galaxy clusters, such as the Perseus, the Coma, or the Virgo cluster, have demonstrated the need for multiple thermal components when spectroscopically fitting the ICM’s X-ray emission, no systematic methodology for calculating

    更新日期:2020-10-16
  • Moderate-resolution K -band Spectroscopy of Substellar Companion κ Andromedae b
    Astron. J. (IF 5.838) Pub Date : 2020-10-14
    Kielan K. Wilcomb, Quinn M. Konopacky, Travis S. Barman, Christopher A. Theissen, Jean-Baptiste Ruffio, Laci Brock, Bruce Macintosh, and Christian Marois

    We present moderate-resolution ( R ∼ 4000) K -band spectra of the “super-Jupiter,” κ Andromedae b. The data were taken with the OSIRIS integral field spectrograph at Keck Observatory. The spectra reveal resolved molecular lines from H 2 O and CO, and are compared to a custom PHOENIX atmosphere model grid appropriate for young planetary-mass objects. We fit the data using a Markov chain Monte Carlo

    更新日期:2020-10-16
  • Detection of Cyclopropenylidene on Titan with ALMA
    Astron. J. (IF 5.838) Pub Date : 2020-10-14
    Conor A. Nixon, Alexander E. Thelen, Martin A. Cordiner, Zbigniew Kisiel, Steven B. Charnley, Edward M. Molter, Joseph Serigano, Patrick G. J. Irwin, Nicholas A. Teanby, and Yi-Jehng Kuan

    We report the first detection on Titan of the small cyclic molecule cyclopropenylidene (c-C 3 H 2 ) from high-sensitivity spectroscopic observations made with the Atacama Large Millimeter/submillimeter Array. Multiple lines of cyclopropenylidene were detected in two separate data sets: ∼251 GHz in 2016 (Band 6) and ∼352 GHz in 2017 (Band 7). Modeling of these emissions indicates abundances of 0.50 ± 0

    更新日期:2020-10-16
  • Utilizing a Database of Simulated Geometric Albedo Spectra for Photometric Characterization of Rocky Exoplanet Atmospheres
    Astron. J. (IF 5.838) Pub Date : 2020-10-14
    Adam J. R. W. Smith, Avi M. Mandell, Geronimo L. Villanueva, and Michaele Dan Moore

    In anticipation of future flagship missions focused on the goal of achieving direct imaging of rocky exoplanets, we have developed a database of models to help the community examine the potential spectral characteristics of a broad range of rocky planet atmospheres. Using the publicly available Planetary Spectrum Generator, we have computed a grid of 141,600 rocky exoplanet geometric albedo spectra

    更新日期:2020-10-16
  • Multi-orbital-phase and Multiband Characterization of Exoplanetary Atmospheres with Reflected Light Spectra
    Astron. J. (IF 5.838) Pub Date : 2020-10-14
    Mario Damiano, Renyu Hu, and Sergi R. Hildebrandt

    Direct imaging of widely separated exoplanets from space will obtain their reflected light spectra and measure atmospheric properties. Previous calculations have shown that a change in the orbital phase would cause a spectral signal, but whether this signal may be used to characterize the atmosphere has not been shown. We simulate starshade-enabled observations of the planet 47 UMa b, using the present

    更新日期:2020-10-16
  • A Featureless Infrared Transmission Spectrum for the Super-puff Planet Kepler-79d
    Astron. J. (IF 5.838) Pub Date : 2020-10-14
    Yayaati Chachan, Daniel Jontof-Hutter, Heather A. Knutson, Danica Adams, Peter Gao, Björn Benneke, Zachory Berta-Thompson, Fei Dai, Drake Deming, Eric B. Ford, Eve J. Lee, Jessica E. Libby-Roberts, Nikku Madhusudhan, Hannah R. Wakeford, and Ian Wong

    Extremely low-density planets (“super-puffs”) are a small but intriguing subset of the transiting planet population. With masses in the super-Earth range (1 − 10 ##IMG## [http://ej.iop.org/images/1538-3881/160/5/201/ajabb23aieqn1.gif] {${M}_{\oplus }$} ) and radii akin to those of giant planets (> 4 ##IMG## [http://ej.iop.org/images/1538-3881/160/5/201/ajabb23aieqn2.gif] {${R}_{\oplus }$} ), their

    更新日期:2020-10-16
  • Reliability Correction is Key for Robust Kepler Occurrence Rates
    Astron. J. (IF 5.838) Pub Date : 2020-10-14
    Steve Bryson, Jeffrey L. Coughlin, Michelle Kunimoto, and Susan E. Mullally

    The Kepler DR25 planet candidate catalog was produced using an automated method of planet candidate identification based on various tests. These tests were tuned to obtain a reasonable but arbitrary balance between catalog completeness and reliability. We produce new catalogs with differing balances of completeness and reliability by varying these tests, and study the impact of these alternative catalogs

    更新日期:2020-10-16
  • Mean Estimate Distances for Galaxies with Multiple Estimates in NED-D
    Astron. J. (IF 5.838) Pub Date : 2020-10-06
    Ian Steer

    Numerous research topics rely on an improved cosmic distance scale (e.g., cosmology, gravitational waves) and the NASA/IPAC Extragalactic Database of Distances (NED-D) supports those efforts by tabulating multiple redshift-independent distances for 12,000 galaxies (e.g., Large Magellanic Cloud (LMC) zero-point). Six methods for securing a mean estimate distance (MED) from the data are presented (e

    更新日期:2020-10-07
  • Phase-curve Pollution of Exoplanet Transit Depths
    Astron. J. (IF 5.838) Pub Date : 2020-10-06
    Marine Martin-Lagarde, Giuseppe Morello, Pierre-Olivier Lagage, René Gastaud, and Christophe Cossou

    The next generation of space telescopes will enable transformative science to understand the nature and origin of exoplanets. In particular, transit spectroscopy will reveal the chemical composition of the exoplanet atmospheres with unprecedented detail thanks to precise measurements of the visible-to-infrared transit depths down to 10 parts per million. Such a level of instrumental precision raises

    更新日期:2020-10-07
  • Prospects for Characterizing the Haziest Sub-Neptune Exoplanets with High-resolution Spectroscopy
    Astron. J. (IF 5.838) Pub Date : 2020-10-06
    Callie E. Hood, Jonathan J. Fortney, Michael R. Line, Emily C. Martin, Caroline V. Morley, Jayne L. Birkby, Zafar Rustamkulov, Roxana E. Lupu, and Richard S. Freedman

    Observations to characterize planets larger than Earth but smaller than Neptune have led to largely inconclusive interpretations at low spectral resolution due to hazes or clouds that obscure molecular features in their spectra. However, here we show that high-resolution spectroscopy ( R ∼ 25,000–100,000) enables one to probe the regions in these atmospheres above the clouds where the cores of the

    更新日期:2020-10-07
  • Light-curve Evolution due to Secular Dynamics and the Vanishing Transits of KOI 120.01
    Astron. J. (IF 5.838) Pub Date : 2020-10-05
    Yair Judkovsky, Aviv Ofir, and Oded Aharonson

    Non-Keplerian dynamics of planetary orbits manifest in the transit light curve as variations of different types. In addition to transit timing variations, the shape of the transits contains additional information on variations in the geometry of the orbit. This study presents an analytic approach to light-curve fitting: dynamical variations in the orbital elements are transformed to a light curve using

    更新日期:2020-10-06
  • A Dynamical Mass of 70 ± 5 M Jup for Gliese 229B, the First T Dwarf
    Astron. J. (IF 5.838) Pub Date : 2020-10-05
    Timothy D. Brandt, Trent J. Dupuy, Brendan P. Bowler, Daniella C. Bardalez Gagliuffi, Jacqueline Faherty, G. Mirek Brandt, and Daniel Michalik

    We combine Keck/HIRES radial velocities, imaging with HiCIAO/Subaru and the Hubble Space Telescope, and absolute astrometry from Hipparcos and Gaia to measure a dynamical mass of 70 ± 5 ##IMG## [http://ej.iop.org/images/1538-3881/160/4/196/ajabb45eieqn1.gif] {${M}_{\mathrm{Jup}}$} for the brown dwarf companion to Gl 229. Gl 229B was the first imaged brown dwarf to show clear signs of methane in its

    更新日期:2020-10-06
  • Impact of Tides on the Potential for Exoplanets to Host Exomoons
    Astron. J. (IF 5.838) Pub Date : 2020-10-05
    Armen Tokadjian and Anthony L. Piro

    Exomoons may play an important role in determining the habitability of worlds outside of our solar system. They can stabilize conditions, alter the climate by breaking tidal locking with the parent star, drive tidal heating, and perhaps even host life themselves. However, the ability of an exoplanet to sustain an exomoon depends on complex tidal interactions. Motivated by this, we make use of simplified

    更新日期:2020-10-06
  • A Dynamic Trajectory Fit to Multisensor Fireball Observations
    Astron. J. (IF 5.838) Pub Date : 2020-09-29
    Trent Jansen-Sturgeon, Eleanor K. Sansom, Hadrien A. R. Devillepoix, Philip A. Bland, Martin C. Towner, Robert M. Howie, and Benjamin A. D. Hartig

    Meteorites with known orbital origins are key to our understanding of solar system formation and the source of life on Earth. Fireball networks have been developed globally in a unified effort to record and ultimately retrieve these cosmic samples. However, the accuracy of the determined orbit and the likelihood of meteorite recovery depend directly on the accuracy of the chosen meteoroid triangulation

    更新日期:2020-09-30
  • Learning Spectral Templates for Photometric Redshift Estimation from Broadband Photometry
    Astron. J. (IF 5.838) Pub Date : 2020-09-29
    John Franklin Crenshaw and Andrew J. Connolly

    Estimating redshifts from broadband photometry is often limited by how accurately we can map the colors of galaxies to an underlying spectral template. Current techniques utilize spectrophotometric samples of galaxies or spectra derived from spectral synthesis models. Both of these approaches have their limitations: either the sample sizes are small and often not representative of the diversity of

    更新日期:2020-09-30
  • The TESS-Keck Survey. III. A Stellar Obliquity Measurement of TOI-1726 c
    Astron. J. (IF 5.838) Pub Date : 2020-09-29
    Fei Dai, Arpita Roy, Benjamin Fulton, Paul Robertson, Lea Hirsch, Howard Isaacson, Simon Albrecht, Andrew W. Mann, Martti H. Kristiansen, Natalie M. Batalha, Corey Beard, Aida Behmard, Ashley Chontos, Ian J. M. Crossfield, Paul A. Dalba, Courtney Dressing, Steven Giacalone, Michelle Hill, Andrew W. Howard, Daniel Huber, Stephen R. Kane, Molly Kosiarek, Jack Lubin, Andrew Mayo, Teo Mocnik, Joseph M

    We report the measurement of a spectroscopic transit of TOI-1726c, one of two planets transiting a G-type star with V = 6.9 in the Ursa Major Moving Group (∼400 Myr). With a precise age constraint from cluster membership, TOI-1726 provides a great opportunity to test various obliquity excitation scenarios that operate on different timescales. By modeling the Rossiter–McLaughlin (RM) effect, we derived

    更新日期:2020-09-30
  • The Habitable Zone Planet Finder Reveals a High Mass and Low Obliquity for the Young Neptune K2-25b
    Astron. J. (IF 5.838) Pub Date : 2020-09-29
    Gudmundur Stefansson, Suvrath Mahadevan, Marissa Maney, Joe P. Ninan, Paul Robertson, Jayadev Rajagopal, Flynn Haase, Lori Allen, Eric B. Ford, Joshua Winn, Angie Wolfgang, Rebekah I. Dawson, John Wisniewski, Chad F. Bender, Caleb Cañas, William Cochran, Scott A. Diddams, Connor Fredrick, Samuel Halverson, Fred Hearty, Leslie Hebb, Shubham Kanodia, Eric Levi, Andrew J. Metcalf, Andrew Monson, Lawrence

    Using radial velocity data from the Habitable Zone Planet Finder, we have measured the mass of the Neptune-sized planet K2-25b, as well as the obliquity of its M4.5 dwarf host star in the 600–800 Myr Hyades cluster. This is one of the youngest planetary systems for which both of these quantities have been measured and one of the very few M dwarfs with a measured obliquity. Based on a joint analysis

    更新日期:2020-09-30
  • A Gaia Survey for Young Stars Associated with the Lupus Clouds
    Astron. J. (IF 5.838) Pub Date : 2020-09-28
    K. L. Luhman

    I have used high-precision photometry and astrometry from the second data release of the Gaia mission to perform a survey for young stars associated with the Lupus clouds, which have distances of ∼160 pc and reside within the Scorpius-Centaurus (Sco-Cen) OB association. The Gaia data have made it possible to distinguish Lupus members from most of the stars in other groups in Sco-Cen that overlap with

    更新日期:2020-09-30
  • A KELT–TESS Eclipsing Binary in a Young Triple System Associated with the Local “Stellar String” Theia 301
    Astron. J. (IF 5.838) Pub Date : 2020-09-28
    Joni-Marie C. Cunningham, Dax L. Feliz, Don M. Dixon, Joshua Pepper, Keivan G. Stassun, Robert J. Siverd, George Zhou, Daniel Bayliss, Thiam-Guan Tan, Phillip Cargile, David James, Rudolf B. Kuhn, and Marina Kounkel

    HD 54236 is a nearby, wide common-proper-motion visual pair that has been previously identified as likely being very young by virtue of strong X-ray emission and lithium absorption. Here, we report the discovery that the brighter member of the wide pair, HD 54236A, is itself an eclipsing binary (EB), comprising two near-equal solar-mass stars on a 2.4 days orbit. It represents a potentially valuable

    更新日期:2020-09-30
  • Optical Transmission Spectroscopy of the Terrestrial Exoplanet LHS 3844b from 13 Ground-based Transit Observations
    Astron. J. (IF 5.838) Pub Date : 2020-09-28
    Hannah Diamond-Lowe, David Charbonneau, Matej Malik, Eliza M.-R. Kempton, and Yuri Beletsky

    Atmospheric studies of spectroscopically accessible terrestrial exoplanets lay the groundwork for comparative planetology between these worlds and the solar system terrestrial planets. LHS 3844b is a highly irradiated terrestrial exoplanet ( R = 1.303 ± 0.022 R ⊕ ) orbiting a mid-M dwarf 15 parsecs away. Work based on near-infrared Spitzer phase curves ruled out atmospheres with surface pressures ≥10

    更新日期:2020-09-30
  • Herbig–Haro Outflows in Circinus W
    Astron. J. (IF 5.838) Pub Date : 2020-09-28
    T. A. Rector, L. Prato, and A. L. Strom

    We report the discovery of new Herbig–Haro (HH) outflows in the Western Circinus molecular cloud. They were found using a color-composite imaging method that reveals faint H α emission in complex environments. Follow-up observations in [S ii ] confirmed their classification as HH objects. Nearly half of the newly discovered objects are part of the HH 76 outflow and are associated with a likely young

    更新日期:2020-09-30
  • Assessment of Variability of the TEC in the Equatorial Anomaly Region with a Focus over Africa Using Rz and F10.7 as Input Drivers
    Astron. J. (IF 5.838) Pub Date : 2020-09-24
    Yekoye Asmare Tariku

    This paper mainly intends to address the assessment of altitudinal variability of the vertical total electron content (VTEC) extracted from the Global Positioning System (GPS), the new versions of the International Reference Ionosphere Extended to the Plasmasphere (IRI-Plas 2017), and a quick-run ionospheric electron density (NeQuick 2) model in the equatorial anomaly region with a focus over Africa

    更新日期:2020-09-25
  • Carbonyl Sulfide (OCS): Detections in Comets C/2002 T7 (LINEAR), C/2015 ER61 (PanSTARRS), and 21P/Giacobini–Zinner and Stringent Upper Limits in 46P/Wirtanen
    Astron. J. (IF 5.838) Pub Date : 2020-09-24
    Mohammad Saki, Erika L. Gibb, Boncho P. Bonev, Nathan X. Roth, Michael A. DiSanti, Neil Dello Russo, Ronald J. Vervack Jr., Adam J. McKay, and Hideyo Kawakita

    Carbonyl sulfide (OCS) is one of the sulfur-bearing molecules detected in different astronomical environments, including comets. The present-day sulfur chemistry in comets may reveal much about the origin of these ices and their subsequent processing history. Cometary sulfur molecules such as H 2 S, H 2 CS, SO 2 , SO, CS, CS 2 , S 2 , and NS have been detected in many comets. However, OCS, the only

    更新日期:2020-09-25
  • OGLE-2018-BLG-0532Lb: Cold Neptune with Possible Jovian Sibling
    Astron. J. (IF 5.838) Pub Date : 2020-09-24
    Yoon-Hyun Ryu, Andrzej Udalski, Jennifer C. Yee, Matthew T. Penny, Weicheng Zang, Michael D. Albrow, Sun-Ju Chung, Andrew Gould, Cheongho Han, Kyu-Ha Hwang, Youn Kil Jung, In-Gu Shin, Yossi Shvartzvald, Sang-Mok Cha, Dong-Jin Kim, Hyoun-Woo Kim, Seung-Lee Kim, Chung-Uk Lee, Dong-Joo Lee, Yongseok Lee, Byeong-Gon Park, Richard W. Pogge (KMTNet Collaboration), Przemek Mróz, Michał K. Szymański, Jan Skowron

    We report the discovery of the planet OGLE-2018-BLG-0532Lb, with very obvious signatures in the light curve that lead to an estimate of the planet-host mass ratio ##IMG## [http://ej.iop.org/images/1538-3881/160/4/183/ajabaa3fieqn1.gif] {$q={M}_{\mathrm{planet}}/{M}_{\mathrm{host}}\simeq 1\times {10}^{-4}$} . Although there are no obvious systematic residuals to this double-lens/single-source (2L1S)

    更新日期:2020-09-25
  • The Southern Stellar Stream Spectroscopic Survey ( S 5 ): Chemical Abundances of Seven Stellar Streams
    Astron. J. (IF 5.838) Pub Date : 2020-09-23
    Alexander P. Ji, Ting S. Li, Terese T. Hansen, Andrew R. Casey, Sergey E. Koposov, Andrew B. Pace, Dougal Mackey, Geraint F. Lewis, Jeffrey D. Simpson, Joss Bland-Hawthorn, Lara R. Cullinane, Gary. S. Da Costa, Kohei Hattori, Sarah L. Martell, Kyler Kuehn, Denis Erkal, Nora Shipp, Zhen Wan, and Daniel B. Zucker

    We present high-resolution Magellan/MIKE spectroscopy of 42 red giant stars in seven stellar streams confirmed by the Southern Stellar Stream Spectroscopic Survey ( S 5 ): ATLAS, Aliqa Uma, Chenab, Elqui, Indus, Jhelum, and Phoenix. Abundances of 30 elements have been derived from over 10,000 individual line measurements or upper limits using photometric stellar parameters and a standard LTE analysis

    更新日期:2020-09-24
  • James Clerk Maxwell Telescope Spectral and Continuum Imaging of Hyperactive Comet 46P/Wirtanen
    Astron. J. (IF 5.838) Pub Date : 2020-09-23
    Iain M. Coulson, Fang-Chun Liu, Martin A. Cordiner, Yi-Jehng Kuan, Yo-Ling Chuang, Steven B. Charnley, Wei-Ling Tseng, Stefanie N. Milam, Wing-Huen Ip, and Zhong-Yi Lin

    The Jupiter-family comet (JFC) 46P/Wirtanen passed the Earth at a distance of 0.077 au on 2018 December 16 UT, presenting a rare opportunity to study the chemical structure of its coma. With the James Clerk Maxwell Telescope we achieved a resolution of 800 km, which is smaller than the scale lengths of some distributed cometary molecules at the comet’s heliocentric distance of 1 au. Spectroscopic observations

    更新日期:2020-09-24
  • On the Orbital Spacing Pattern of Kepler Multiple-planet Systems
    Astron. J. (IF 5.838) Pub Date : 2020-09-23
    Chao-Feng Jiang, Ji-Wei Xie, and Ji-Lin Zhou

    The Kepler space mission has detected a large number of exoplanets in multiple transiting planet systems. Previous studies found that these Kepler multiple-planet systems exhibit an intra-system uniformity, namely planets in the same system have similar sizes and correlated orbital spacings. However, it is important to consider the possible role of selection effects due to observational biases. In

    更新日期:2020-09-24
  • TESS Hunt for Young and Maturing Exoplanets (THYME). III. A Two-planet System in the 400 Myr Ursa Major Group
    Astron. J. (IF 5.838) Pub Date : 2020-09-23
    Andrew W. Mann, Marshall C. Johnson, Andrew Vanderburg, Adam L. Kraus, Aaron C. Rizzuto, Mackenna L. Wood, Jonathan L. Bush, Keighley Rockcliffe, Elisabeth R. Newton, David W. Latham, Eric E. Mamajek, George Zhou, Samuel N. Quinn, Pa Chia Thao, Serena Benatti, Rosario Cosentino, Silvano Desidera, Avet Harutyunyan, Christophe Lovis, Annelies Mortier, Francesco A. Pepe, Ennio Poretti, Thomas G. Wilson

    Exoplanets can evolve significantly between birth and maturity, as their atmospheres, orbits, and structures are shaped by their environment. Young planets (<1 Gyr) offer an opportunity to probe the critical early stages of this evolution, where planets evolve the fastest. However, most of the known young planets orbit prohibitively faint stars. We present the discovery of two planets transiting HD

    更新日期:2020-09-24
  • Near-infrared Characterization of Four Massive Stars in Transition Phases
    Astron. J. (IF 5.838) Pub Date : 2020-09-20
    Yanina R. Cochetti, Michaela Kraus, María L. Arias, Lydia S. Cidale, Tõnis Eenmäe, Tiina Liimets, Andrea F. Torres, and Anlaug A. Djupvik

    Massive stars typically undergo short-lived post-main-sequence evolutionary phases with strong mass loss and occasional mass eruptions. Many of such massive stars in transition phases have been identified based on their dusty envelopes. The ejected material often veils the stellar photospheres so that the central stars cannot be assigned proper spectral types and evolutionary stages. The infrared spectral

    更新日期:2020-09-21
  • HAWC+ Far-infrared Observations of the Magnetic Field Geometry in M51 and NGC 891
    Astron. J. (IF 5.838) Pub Date : 2020-09-20
    Terry Jay Jones, Jin-Ah Kim, C. Darren Dowell, Mark R. Morris, Jorge L. Pineda, Dominic J. Benford, Marc Berthoud, David T. Chuss, Daniel A. Dale, L. M. Fissel, Paul F. Goldsmith, Ryan T. Hamilton, Shaul Hanany, Doyal A. Harper, Thomas K. Henning, Alex Lazarian, Leslie W. Looney, Joseph M. Michail, Giles Novak, Fabio P. Santos, Kartik Sheth, Javad Siah, Gordon J. Stacey, Johannes Staguhn, Ian W. Stephens

    Stratospheric Observatory for Infrared Astronomy High-resolution Airborne Wideband Camera Plus polarimetry at 154 μ m is reported for the face-on galaxy M51 and the edge-on galaxy NGC 891. For M51, the polarization vectors generally follow the spiral pattern defined by the molecular gas distribution, the far-infrared (FIR) intensity contours, and other tracers of star formation. The fractional polarization

    更新日期:2020-09-21
  • π Earth: A 3.14 day Earth-sized Planet from K2's Kitchen Served Warm by the SPECULOOS Team
    Astron. J. (IF 5.838) Pub Date : 2020-09-20
    Prajwal Niraula, Julien de Wit, Benjamin V. Rackham, Elsa Ducrot, Artem Burdanov, Ian J. M. Crossfield, Valérie Van Grootel, Catriona Murray, Lionel J. Garcia, Roi Alonso, Corey Beard, Yilen Gómez Maqueo Chew, Laetitia Delrez, Brice-Olivier Demory, Benjamin J. Fulton, Michaël Gillon, Maximilian N. Günther, Andrew W. Howard, Howard Issacson, Emmanuël Jehin, Peter P. Pedersen, Francisco J. Pozuelos,

    We report on the discovery of a transiting Earth-sized (0.95 R ⊕ ) planet around an M3.5 dwarf star at 57 pc, EPIC 249631677. The planet has a period of ∼3.14 days, i.e., ∼ π , with an installation of 7.45 S ⊕ . The detection was made using publicly available data from K2's Campaign 15. We observed three additional transits with SPECULOOS Southern and Northern Observatories, and a stellar spectrum

    更新日期:2020-09-21
  • The Ubiquity of AGN Winds in Seyfert 1 Galaxies at Low Redshift
    Astron. J. (IF 5.838) Pub Date : 2020-09-20
    Juan Pablo Torres-Papaqui, Roger Coziol, Fernando J. Romero-Cruz, Aitor C. Robleto-Orús, Gabriela Escobar-Vásquez, Abdías Morales-Vargas, J. J. Trejo-Alonso, Marcel Chow-Martínez, and Karla A. Cutiva-Alvarez

    The optical spectra of 3896 Seyfert 1 (Sy1) galaxies detected with WISE at z < 0.4 were analyzed for evidence of outflows. In 37% of the Sy1s in our sample, the outflows appear as broad, blue-shifted, spectrally resolved components of the [O iii ] λ 5007 Å emission line, with a mean maximum velocity V max ∼ 1014 km s −1 that is consistent with AGN winds. For each Sy1, we deduced the black hole (BH)

    更新日期:2020-09-21
  • Multiple Transits during a Single Conjunction: Identifying Transiting Circumbinary Planetary Candidates from TESS
    Astron. J. (IF 5.838) Pub Date : 2020-09-20
    Veselin B. Kostov, William F. Welsh, Nader Haghighipour, Billy Quarles, Eric Agol, Laurance Doyle, Daniel C. Fabrycky, Gongjie Li, David V. Martin, Sean Mills, Tsevi Mazeh, Jerome A. Orosz, and Brian P. Powell

    We present results of a study on identifying circumbinary planet candidates that produce multiple transits during one conjunction with eclipsing binary systems. The occurrence of these transits enables us to estimate the candidates’ orbital periods, which is crucial as the periods of the currently known transiting circumbinary planets are significantly longer than the typical observational baseline

    更新日期:2020-09-21
  • C 2 N 2 Vertical Profile in Titan’s Stratosphere
    Astron. J. (IF 5.838) Pub Date : 2020-09-20
    M. Sylvestre, N. A. Teanby, M. Dobrijevic, J. Sharkey, and P. G. J. Irwin

    In this paper, we present the first measurements of the vertical distribution of cyanogen ( ##IMG## [http://ej.iop.org/images/1538-3881/160/4/178/ajabafb2ieqn1.gif] {${{\rm{C}}}_{2}{{\rm{N}}}_{2}$} ) in Titan’s lower atmosphere at different latitudes and seasons, using Cassini’s Composite Infrared Spectrometer far-infrared data. We also study the vertical distribution of three other minor species detected

    更新日期:2020-09-21
  • Mathematical Underpinnings of the Multiwavelength Structure of the Tip of the Red Giant Branch
    Astron. J. (IF 5.838) Pub Date : 2020-09-20
    Barry F. Madore and Wendy L. Freedman

    We consider the application of the tip of the red giant branch (TRGB) in the optical and in the near-infrared for the determination of distances to nearby galaxies. We analyze ACS VI (F555W and F814W) data and self-consistently cross-calibrate WFC3-IR JH (F110W and F120W) data using an absolute magnitude calibration of M I = −4.05 mag as determined in the Large Magellanic Cloud using detached eclipsing

    更新日期:2020-09-21
  • Integrating Light Curve and Atmospheric Modeling of Transiting Exoplanets
    Astron. J. (IF 5.838) Pub Date : 2020-09-20
    K. H. Yip, A. Tsiaras, I. P. Waldmann, and G. Tinetti

    Spectral retrieval techniques are currently our best tool to interpret the observed exoplanet atmospheric data. Said techniques retrieve the optimal atmospheric components and parameters by identifying the best fit to an observed transmission/emission spectrum. Over the past decade, our understanding of remote worlds in our galaxy has flourished thanks to the use of increasingly sophisticated spectral

    更新日期:2020-09-21
  • Astraea : Predicting Long Rotation Periods with 27 Day Light Curves
    Astron. J. (IF 5.838) Pub Date : 2020-09-20
    Yuxi(Lucy) Lu, Ruth Angus, Marcel A. Agüeros, Kirsten Blancato, Melissa Ness, Danielle Rowland, Jason L. Curtis, and Sam Grunblatt

    The rotation periods of planet-hosting stars can be used for modeling and mitigating the impact of magnetic activity in radial velocity measurements and can help constrain the high-energy flux environment and space weather of planetary systems. Millions of stars and thousands of planet hosts are observed with the Transiting Exoplanet Survey Satellite (TESS). However, most will only be observed for

    更新日期:2020-09-21
  • BVR C I C Observations and Analysis of the UV LEO-type Binary, the Pre-WUMa, V1023 Persei
    Astron. J. (IF 5.838) Pub Date : 2020-09-20
    Ronald Samec, Daniel Caton, and Danny R. Faulkner

    V1023 Per is a polar spotted, but well-detached dwarf binary, very likely a Pre-WUMa eclipsing binary. It was observed on 11 nights in 2015 October, November, and December at Dark Sky Observatory in North Carolina with the 0.81 m reflector of Appalachian State University. The period behavior is complex and may be increasing with a cubic or quadratic ephemeris. Its odd light curves are of high amplitude

    更新日期:2020-09-21
  • WIYN Open Cluster Study. LXXXII. Radial-velocity Measurements and Spectroscopic Binary Orbits in the Open Cluster NGC 7789
    Astron. J. (IF 5.838) Pub Date : 2020-09-20
    Andrew C. Nine, Katelyn E. Milliman, Robert D. Mathieu, Aaron M. Geller, Emily M. Leiner, Imants Platais, and Benjamin M. Tofflemire

    We present an extensive time-series radial-velocity (RV) survey of stars in the rich open cluster NGC 7789 (1.6 Gyr, [Fe/H] = +0.02). The stellar sample lies within an 18′ circular radius from the cluster center (10 pc in projection, or about 2 core radii), and includes giants, red clump stars, blue stragglers, red stragglers, sub-subgiants, and main-sequence stars down to 1 mag below the turnoff.

    更新日期:2020-09-21
  • Evidence of Systematic Errors in Spitzer Microlens Parallax Measurements
    Astron. J. (IF 5.838) Pub Date : 2020-09-20
    Naoki Koshimoto and David P. Bennett

    The microlensing parallax campaign with the Spitzer space telescope aims to measure masses and distances of microlensing events seen toward the Galactic bulge, with a focus on planetary microlensing events. The hope is to measure how the distribution of planets depends on position within the Galaxy. In this paper, we compare 50 microlens parallax measurements from the 2015 Spitzer campaign to three

    更新日期:2020-09-21
  • The Most Metal-poor Stars in the Inner Bulge
    Astron. J. (IF 5.838) Pub Date : 2020-09-20
    Henrique Reggiani, Kevin C. Schlaufman, Andrew R. Casey, and Alexander P. Ji

    The bulge is the oldest component of the Milky Way. Since numerous simulations of Milky Way formation have predicted that the oldest stars at a given metallicity are found on tightly bound orbits, the Galaxy’s oldest stars are likely metal-poor stars in the inner bulge with small apocenters (i.e., R apo ≲ 4 kpc). In the past, stars with these properties have been impossible to find due to extreme reddening

    更新日期:2020-09-21
  • The Outburst of the Young Star Gaia19bey
    Astron. J. (IF 5.838) Pub Date : 2020-09-10
    Klaus W. Hodapp, Larry Denneau, Michael Tucker, Benjamin J. Shappee, Mark E. Huber, Anna V. Payne, Aaron Do, Chien-Cheng Lin, Michael S. Connelley, Watson P. Varricatt, John Tonry, Kenneth Chambers, and Eugene Magnier

    We report photometry and spectroscopy of the outburst of the young stellar object Gaia19bey. We have established the outburst light curve with archival Gaia “ G ,” ATLAS “Orange,” Zwicky Transient Facility r -band, and Pan-STARRS “ rizy ”-filter photometry, showing an outburst of ~4 yr duration, longer than typical EX Lupi objects but shorter than FU Orionis objects. Its pre-outburst spectral energy

    更新日期:2020-09-11
  • SCExAO/CHARIS Near-infrared Integral Field Spectroscopy of the HD 15115 Debris Disk
    Astron. J. (IF 5.838) Pub Date : 2020-09-10
    Kellen Lawson, Thayne Currie, John P. Wisniewski, Motohide Tamura, Glenn Schneider, Jean-Charles Augereau, Timothy D. Brandt, Olivier Guyon, N. Jeremy Kasdin, Tyler D. Groff, Julien Lozi, Jeffrey Chilcote, Klaus Hodapp, Nemanja Jovanovic, Frantz Martinache, Nour Skaf, Eiji Akiyama, Thomas Henning, Gillian R. Knapp, Jungmi Kwon, Satoshi Mayama, Michael W. McElwain, Michael L. Sitko, Ruben Asensio-Torres

    We present new, near-infrared (1.1–2.4 μ m) high-contrast imaging of the debris disk around HD 15115 with the Subaru Coronagraphic Extreme Adaptive Optics (SCExAO) system coupled with the Coronagraphic High Angular Resolution Imaging Spectrograph (CHARIS). The SCExAO/CHARIS resolves the disk down to ρ ∼ 0.″2 ( r proj ∼ 10 au), a factor of ∼3–5 smaller than previous recent studies. We derive a disk

    更新日期:2020-09-11
  • An ATA Search for a Repetition of the Wow Signal
    Astron. J. (IF 5.838) Pub Date : 2020-09-10
    G. R. Harp, R. H. Gray, J. Richards, G. S. Shostak, and J. C. Tarter

    The Allen Telescope Array was used to search for signals with characteristics similar to the “Wow” signal, the best candidate for an extraterrestrial radio signal found during Ohio State University’s (OSU’s) seven-year 21 cm 10-kHz channel sky survey for signals possibly due to extraterrestrial intelligence. While previous follow-up searches have reported null results, our observations covered a 5

    更新日期:2020-09-11
  • NGC 4869 in the Coma Cluster: Twist, Wrap, Overlap, and Bend
    Astron. J. (IF 5.838) Pub Date : 2020-09-10
    Dharam V. Lal

    The upgraded Giant Metrewave Radio Telescope (GMRT) has been used to image the head–tail radio galaxy NGC 4869 in the Coma cluster with an angular resolution of 6.″26 at 250–500 MHz and 2.″18 at the 1050–1450 MHz bands. The archival legacy GMRT data have also been used to image the source with angular resolutions from 4.″9 to 21.″8 at 610 MHz, 325 MHz, 240 MHz, and 150 MHz. We find that the ∼200 kpc scale

    更新日期:2020-09-11
  • Emission-line Data Cubes of the HH 32 Stellar Jet
    Astron. J. (IF 5.838) Pub Date : 2020-09-10
    Patrick Hartigan, Lynne A. Hillenbrand, Matuesz Matuszewski, Arlindo Chan Borges, James D. Neill, D. Christopher Martin, Patrick Morrissey, and Anna M. Moore

    We analyze data cubes of over 60 emission lines in the HH 32 stellar jet acquired with the Keck Cosmic Web Imager (KCWI). The data cover the less explored blue portion of the spectrum between 3586 and 6351 Å and have both high spectral ( R ∼ 10,000) and spatial (≲1″) resolution. The study includes all three major ionization states of oxygen, three Balmer lines, multiple lines of Fe ii and Fe iii ,

    更新日期:2020-09-11
  • MIRC-X: A Highly Sensitive Six-telescope Interferometric Imager at the CHARA Array
    Astron. J. (IF 5.838) Pub Date : 2020-09-09
    Narsireddy Anugu, Jean-Baptiste Le Bouquin, John D. Monnier, Stefan Kraus, Benjamin R. Setterholm, Aaron Labdon, Claire L Davies, Cyprien Lanthermann, Tyler Gardner, Jacob Ennis, Keith J. C. Johnson, Theo Ten Brummelaar, Gail Schaefer, and Judit Sturmann

    Michigan InfraRed Combiner-eXeter (MIRC-X) is a new highly sensitive six-telescope interferometric imager installed at the CHARA Array that provides an angular resolution equivalent of up to a 330 m diameter baseline telescope in J - and H -band wavelengths ( ##IMG## [http://ej.iop.org/images/1538-3881/160/4/158/ajaba957ieqn1.gif] {$\tfrac{\lambda }{2B}\sim 0.6$} mas). We upgraded the original Michigan

    更新日期:2020-09-10
  • Measuring Transit Signal Recovery in the Kepler Pipeline. IV. Completeness of the DR25 Planet Candidate Catalog
    Astron. J. (IF 5.838) Pub Date : 2020-09-09
    Jessie L. Christiansen, Bruce D. Clarke, Christopher J. Burke, Jon M. Jenkins, Stephen T. Bryson, Jeffrey L. Coughlin, Susan E. Mullally, Joseph D. Twicken, Natalie M. Batalha, Joseph Catanzarite, AKM Kamal Uddin, Khadeejah Zamudio, Jeffrey C. Smith, Christopher E. Henze, and Jennifer Campbell

    In this work we empirically measure the detection efficiency of the Kepler pipeline used to create the final Kepler threshold crossing event and planet candidate catalogs, a necessary ingredient for occurrence-rate calculations using these lists. By injecting simulated signals into the calibrated pixel data and processing those pixels through the pipeline as normal, we quantify the detection probability

    更新日期:2020-09-10
  • Peas in a Pod? Radius Correlations in Kepler Multiplanet Systems
    Astron. J. (IF 5.838) Pub Date : 2020-09-09
    Lena Murchikova and Scott Tremaine

    We address the claim of Weiss et al. that the radii of adjacent planets in Kepler multiplanet systems are correlated. We explore two simple toy models—in the first the radii of the planets are chosen at random from a single universal distribution, and in the second we postulate several types of systems with distinct radius distributions. We show that an apparent correlation between the radii of adjacent

    更新日期:2020-09-10
  • Systematic Phase Curve Study of Known Transiting Systems from Year One of the TESS Mission
    Astron. J. (IF 5.838) Pub Date : 2020-09-03
    Ian Wong, Avi Shporer, Tansu Daylan, Björn Benneke, Tara Fetherolf, Stephen R. Kane, George R. Ricker, Roland Vanderspek, David W. Latham, Joshua N. Winn, Jon M. Jenkins, Patricia T. Boyd, Ana Glidden, Robert F. Goeke, Lizhou Sha, Eric B. Ting, and Daniel Yahalomi

    We present a systematic phase curve analysis of known transiting systems observed by the Transiting Exoplanet Survey Satellite (TESS) during year one of the primary mission. Using theoretical predictions for the amplitude of the planetary longitudinal atmospheric brightness modulation, stellar ellipsoidal distortion and Doppler boosting, as well as brightness considerations to select targets with likely

    更新日期:2020-09-05
  • The Sizes of z ∼ 9−10 Galaxies Identified in the Brightest of Reionizing Galaxies (BoRG) Survey
    Astron. J. (IF 5.838) Pub Date : 2020-09-03
    Benne W. Holwerda, Joanna S. Bridge, Rebecca L. Steele, Samir Kusmic, Larry Bradley, Rachael Livermore, Stephanie Bernard, and Alice Jacques

    Redshift z = 9–10 object selection is the effective limit of Hubble Space Telescope (HST) imaging capability, even when confirmed with Spitzer. If only a few photometry data points are available, it becomes attractive to add criteria based on their morphology in these J - and H -band images. One could do so through visual inspection, a size criterion, or alternate morphometrics. We explore a vetted

    更新日期:2020-09-05
  • The Nebula N103B in the LMC Contains Parts of Two Supernova Remnants
    Astron. J. (IF 5.838) Pub Date : 2020-09-03
    John R. Dickel

    The nebula N103B in the Large Magellanic Cloud consists of a previously identified small diameter supernova remnant (SNR) on its northeastern edge and a bright eastern arc with a fainter western shell together covering a total of about 8 × 5′ at the canonical distance of 50 kpc. The latter also has a nonthermal radio spectrum and is apparently another SNR. I propose that the small bright northeastern

    更新日期:2020-09-05
  • Discovery of a Nearby Young Brown Dwarf Disk
    Astron. J. (IF 5.838) Pub Date : 2020-09-03
    Maria C. Schutte, Kellen D. Lawson, John P. Wisniewski, Marc J. Kuchner, Steven M. Silverberg, Jacqueline K. Faherty, Daniella C. Bardalez Gagliuffi, Rocio Kiman, Jonathan Gagné, Aaron Meisner, Adam C. Schneider, Alissa S. Bans, John H. Debes, Natalie Kovacevic, Milton K. D. Bosch, Hugo A. Durantini Luca, Jonathan Holden, Michiharu Hyogo, and The Disk Detective Collaboration

    We report the discovery of the youngest brown dwarf with a disk at 102 pc from the Sun, WISEA J120037.79−784508.3 (W1200−7845), via the Disk Detective citizen science project. We establish that W1200−7845 is located in the ##IMG## [http://ej.iop.org/images/1538-3881/160/4/156/ajabaccdieqn1.gif] {${3.7}_{-1.4}^{+4.6}$} Myr old ε Cha association. Its spectral energy distribution (SED) exhibits clear

    更新日期:2020-09-05
  • TOI-824 b: A New Planet on the Lower Edge of the Hot Neptune Desert
    Astron. J. (IF 5.838) Pub Date : 2020-09-03
    Jennifer A. Burt, Louise D. Nielsen, Samuel N. Quinn, Eric E. Mamajek, Elisabeth C. Matthews, George Zhou, Julia V. Seidel, Chelsea X. Huang, Eric Lopez, Maritza Soto, Jon Otegi, Keivan G. Stassun, Laura Kreidberg, Karen A. Collins, Jason D. Eastman, Joseph E. Rodriguez, Andrew Vanderburg, Samuel P. Halverson, Johanna K. Teske, Sharon X. Wang, R. Paul Butler, François Bouchy, Xavier Dumusque, Damien

    We report the detection of a transiting hot Neptune exoplanet orbiting TOI-824 (SCR J1448-5735), a nearby ( d = 64 pc) K4V star, using data from the Transiting Exoplanet Survey Satellite. The newly discovered planet has a radius R p = 2.93 ± 0.20 ##IMG## [http://ej.iop.org/images/1538-3881/160/4/153/ajabac0cieqn1.gif] {${R}_{\oplus }$} and an orbital period of 1.393 days. Radial velocity measurements

    更新日期:2020-09-05
  • The Dynamics of the Wide-angle Tailed (WAT) Galaxy Cluster A562
    Astron. J. (IF 5.838) Pub Date : 2020-09-02
    P. L. Gómez and D. Calderón

    We present the first in-depth dynamical analysis of the archetypal wide-angle tailed (WAT) cluster A562. We have combined Gemini observations with archival data from the literature to form a sample of 76 cluster members and derived a mean redshift of 0.1088 ± 0.0004 and a velocity dispersion of 919 ± 116 km s −1 . This relatively large velocity dispersion suggests either a very massive cluster ( M

    更新日期:2020-09-03
  • Follow-up Studies of Five Cataclysmic Variable Candidates Discovered by LAMOST
    Astron. J. (IF 5.838) Pub Date : 2020-09-02
    John R. Thorstensen

    We report follow-up observations of five cataclysmic variable candidates from the Large Sky Area Multi-Object Fiber Spectroscopic Telescope (LAMOST) published by Hou et al. LAMOST J024048.51+195226.9 is the most unusual of the five; an early-M type secondary star contributes strongly to its spectrum, and its spectral and photometric behavior are strikingly reminiscent of the hitherto-unique propeller

    更新日期:2020-09-03
  • On the Chemical Abundance of HR 8799 and the Planet c
    Astron. J. (IF 5.838) Pub Date : 2020-09-01
    Ji Wang, Jason J. Wang, Bo Ma, Jeffrey Chilcote, Steve Ertel, Olivier Guyon, Ilya Ilyin, Nemanja Jovanovic, Paul Kalas, Julien Lozi, Bruce Macintosh, Klaus G. Strassmeier, and Jordan Stone

    Comparing chemical abundances of a planet and the host star reveals the origin and formation pathway of the planet. Stellar abundance is measured with high-resolution spectroscopy. Planet abundance, on the other hand, is usually inferred from low-resolution data. For directly imaged exoplanets, the data are available from a slew of high-contrast imaging/spectroscopy instruments. Here, we study the

    更新日期:2020-09-02
  • A Warm Jupiter Transiting an M Dwarf: A TESS Single-transit Event Confirmed with the Habitable-zone Planet Finder
    Astron. J. (IF 5.838) Pub Date : 2020-09-01
    Caleb I. Cañas, Gudmundur Stefansson, Shubham Kanodia, Suvrath Mahadevan, William D. Cochran, Michael Endl, Paul Robertson, Chad F. Bender, Joe P. Ninan, Corey Beard, Jack Lubin, Arvind F. Gupta, Mark E. Everett, Andrew Monson, Robert F. Wilson, Hannah M. Lewis, Mary Brewer, Steven R. Majewski, Leslie Hebb, Rebekah I. Dawson, Scott A. Diddams, Eric B. Ford, Connor Fredrick, Samuel Halverson, Fred Hearty

    We confirm the planetary nature of a warm Jupiter transiting the early M dwarf TOI-1899 using a combination of available TESS photometry; high-precision, near-infrared spectroscopy with the Habitable-zone Planet Finder; and speckle and adaptive optics imaging. The data reveal a transiting companion on an ∼29 day orbit with a mass and radius of ##IMG## [http://ej.iop.org/images/1538-3881/160/3/147/ajabac67ieqn1

    更新日期:2020-09-02
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