Welcome to the AOP Open Repository

• Deconvolving the complex structure of the asteroid belt

  Department of Astronomy, University of Florida, Gainesville, FL, 32611, US; NSF's National Optical-Infrared Astronomy Research Laboratory, Tucson, AZ, 85719, US; Armagh Observatory and Planetarium, College Hill, Armagh, BT61 9DG; Dermott, Stanley F.; Li, Dan; Christou, Apostolos A. (Complex Planetary Systems II: Latest Methods for an Interdisciplinary Approach, 2024-01-01)

  The asteroid belt is a unique source of information on some of the most important questions facing solar system science. These questions include the sizes, numbers, types and orbital distributions of the planetesimals that formed the planets, and the identification of those asteroids that are the sources of meteorites and near-Earth asteroids. Answering these questions requires an understanding of the dynamical evolution of the asteroid belt, but this evolution is governed by a complex interplay of mechanisms that include catastrophic disruption, orbital evolution driven by Yarkovsky radiation forces, and chaotic orbital evolution driven by gravitational forces. While the timescales of these loss mechanisms have been calculated using estimates of some critical parameters that include the thermal properties, strengths and mean densities of the asteroids, we argue here that the uncertainties in these parameters are so large that deconvolution of the structure of the asteroid belt must be guided primarily by observational constraints. We argue that observations of the inner asteroid belt indicate that the size-frequency distribution is not close to the equilibrium distribution postulated by Dohnanyi (<xref rid=ref10 ref-type=bibr>1969</xref>). We also discuss the correlations observed between the sizes and the orbital elements of the asteroids. While some of these correlations are significant and informative, others are spurious and may arise from the limitations of the Hierarchical Clustering Method that is currently used to define family membership.
• NGTS-33b: A Young Super-Jupiter Hosted by a Fast Rotating Massive Hot Star

  Departamento de Astronomía, Universidad de Chile, Casilla 36-D, Santiago, Chile; Centro de Astrofísica y Tecnologías Afines (CATA), Casilla 36-D, Santiago, Chile;; Instituto de Estudios Astrofísicos, Universidad Diego Portales, Av. Ejército 441, Santiago, Chile; Centro de Astrofísica y Tecnologías Afines (CATA), Casilla 36-D, Santiago, Chile; Instituto de Astronomía, Universidad Católica del Norte, Angamos 0610, 1270709, Antofagasta, Chile; Departement d'Astronomie, Université de Genève, 51 chemin Pegasi, 1290 Sauverny, Switzerland; Departement d'Astronomie, Université de Genève, 51 chemin Pegasi, 1290 Sauverny, Switzerland;; University Observatory, Faculty of Physics, Ludwig-Maximilians-Universität München, Scheinerstr. 1, 81679 Munich, Germany;; Department of Physics, University of Warwick, Gibbet Hill Road, Coventry CV4 7AL, UK; Centre for Exoplanets and Habitability, University of Warwick, Gibbet Hill Road, Coventry CV4 7AL, UK; School of Physics and Astronomy, University of Leicester, Leicester LE1 7RH, UK; School of Physics and Astronomy, University of Leicester, Leicester LE1 7RH, UK;; Department of Physics and Astronomy, McMaster University, 1280 Main St W, Hamilton, ON, L8S 4L8, Canada; et al. (Monthly Notices of the Royal Astronomical Society, 2024-11-01)

  In the last few decades planet search surveys have been focusing on solar type stars, and only recently the high-mass regimes. This is mostly due to challenges arising from the lack of instrumental precision, and more importantly, the inherent active nature of fast rotating massive stars. Here we report NGTS-33b (TOI-6442b), a super-Jupiter planet with mass, radius and orbital period of 3.6 ± 0.3 M<SUB>j</SUB>, 1.64 ± 0.07 R<SUB>j</SUB> and 2.827972 ± 0.000001 days, respectively. The host is a fast rotating (0.6654 ± 0.0006 day) and hot (T<SUB>eff</SUB> = 7437 ± 72 K) A9V type star, with a mass and radius of 1.60 ± 0.11 M<SUB>⊙</SUB> and 1.47 ± 0.06 R<SUB>⊙</SUB>, respectively. Planet structure and Gyrochronology models shows that NGTS-33 is also very young with age limits of 10-50 Myr. In addition, membership analysis points towards the star being part of the Vela OB2 association, which has an age of ~ 20-35 Myr, thus providing further evidences about the young nature of NGTS-33. Its low bulk density of 0.19±0.03 gcm<SUP>-3</SUP> is 13<inline-formula><tex-math id=TM0001 notation=LaTeX>$\%$</tex-math></inline-formula> smaller than expected when compared to transiting hot Jupiters with similar masses. Such cannot be solely explained by its age, where an up to 15<inline-formula><tex-math id=TM0002 notation=LaTeX>$\%$</tex-math></inline-formula> inflated atmosphere is expected from planet structure models. Finally, we found that its emission spectroscopy metric is similar to JWST community targets, making the planet an interesting target for atmospheric follow-up. Therefore, NGTS-33b's discovery will not only add to the scarce population of young, massive and hot Jupiters, but will also help place further strong constraints on current formation and evolution models for such planetary systems.
• NGTS-33b: A Young Super-Jupiter Hosted by a Fast Rotating Massive Hot Star

  Departamento de Astronomía, Universidad de Chile, Casilla 36-D, Santiago, Chile; Centro de Astrofísica y Tecnologías Afines (CATA), Casilla 36-D, Santiago, Chile;; Instituto de Estudios Astrofísicos, Universidad Diego Portales, Av. Ejército 441, Santiago, Chile; Centro de Astrofísica y Tecnologías Afines (CATA), Casilla 36-D, Santiago, Chile; Instituto de Astronomía, Universidad Católica del Norte, Angamos 0610, 1270709, Antofagasta, Chile; Departement d'Astronomie, Université de Genève, 51 chemin Pegasi, 1290 Sauverny, Switzerland; Departement d'Astronomie, Université de Genève, 51 chemin Pegasi, 1290 Sauverny, Switzerland;; University Observatory, Faculty of Physics, Ludwig-Maximilians-Universität München, Scheinerstr. 1, 81679 Munich, Germany;; Department of Physics, University of Warwick, Gibbet Hill Road, Coventry CV4 7AL, UK; Centre for Exoplanets and Habitability, University of Warwick, Gibbet Hill Road, Coventry CV4 7AL, UK; School of Physics and Astronomy, University of Leicester, Leicester LE1 7RH, UK; School of Physics and Astronomy, University of Leicester, Leicester LE1 7RH, UK;; Department of Physics and Astronomy, McMaster University, 1280 Main St W, Hamilton, ON, L8S 4L8, Canada; et al. (Monthly Notices of the Royal Astronomical Society, 2024-11-01)

  In the last few decades planet search surveys have been focusing on solar type stars, and only recently the high-mass regimes. This is mostly due to challenges arising from the lack of instrumental precision, and more importantly, the inherent active nature of fast rotating massive stars. Here we report NGTS-33b (TOI-6442b), a super-Jupiter planet with mass, radius and orbital period of 3.6 ± 0.3 M<SUB>j</SUB>, 1.64 ± 0.07 R<SUB>j</SUB> and 2.827972 ± 0.000001 days, respectively. The host is a fast rotating (0.6654 ± 0.0006 day) and hot (T<SUB>eff</SUB> = 7437 ± 72 K) A9V type star, with a mass and radius of 1.60 ± 0.11 M<SUB>⊙</SUB> and 1.47 ± 0.06 R<SUB>⊙</SUB>, respectively. Planet structure and Gyrochronology models shows that NGTS-33 is also very young with age limits of 10-50 Myr. In addition, membership analysis points towards the star being part of the Vela OB2 association, which has an age of ~ 20-35 Myr, thus providing further evidences about the young nature of NGTS-33. Its low bulk density of 0.19±0.03 gcm<SUP>-3</SUP> is 13<inline-formula><tex-math id=TM0001 notation=LaTeX>$\%$</tex-math></inline-formula> smaller than expected when compared to transiting hot Jupiters with similar masses. Such cannot be solely explained by its age, where an up to 15<inline-formula><tex-math id=TM0002 notation=LaTeX>$\%$</tex-math></inline-formula> inflated atmosphere is expected from planet structure models. Finally, we found that its emission spectroscopy metric is similar to JWST community targets, making the planet an interesting target for atmospheric follow-up. Therefore, NGTS-33b's discovery will not only add to the scarce population of young, massive and hot Jupiters, but will also help place further strong constraints on current formation and evolution models for such planetary systems.
• ALMASOP. The Localized and Chemically Rich Features near the Bases of the Protostellar Jet in HOPS 87

  Institute of Astronomy and Astrophysics, Academia Sinica, No.1, Sec 4, Roosevelt Road, Taipei 106216, Taiwan, (R.O.C.);; NRC Herzberg Astronomy and Astrophysics, 5071 West Saanich Road, Victoria, BC, V9E 2E7, Canada; Department of Physics and Astronomy, University of Victoria, Victoria, BC, V8P 5C2, Canada;; Key Laboratory for Research in Galaxies and Cosmology, Shanghai Astronomical Observatory, Chinese Academy of Sciences, 80 Nandan Road, Shanghai 200030, People's Republic of China;; National Astronomical Observatory of Japan, 2-21-1 Osawa, Mitaka, Tokyo 181-8588, Japan; Astronomical Science Program, The Graduate University for Advanced Studies, SOKENDAI, 2-21-1 Osawa, Mitaka, Tokyo 181-8588, Japan;; Departamento de Astronomía, Universidad de Chile, Casilla 36-D, Santiago, Chile;; Department of Physics and Institute of Astronomy, National Tsing Hua University, Hsinchu, 30013, Taiwan;; Armagh Observatory and Planetarium, College Hill, Armagh, BT61 9DB, UK;; Department of Astronomy, The University of Texas at Austin, 2515 Speedway, Stop C1400, Austin, TX 78712-1205, USA;; Department of Physics, P.O. Box 64, FI-00014, University of Helsinki, Finland;; Institute of Astronomy and Astrophysics, Academia Sinica, No.1, Sec 4, Roosevelt Road, Taipei 106216, Taiwan, (R.O.C.); Department of Earth Sciences, National Taiwan Normal University, Taipei, Taiwan, (R.O.C.);; et al. (The Astrophysical Journal, 2024-11-01)

  HOPS 87 is a Class 0 protostellar core known to harbor an extremely young bipolar outflow and a hot corino. We report the discovery of localized, chemically rich regions near the bases of the two-lobe bipolar molecular outflow in HOPS 87 containing molecules such as H<SUB>2</SUB>CO, <SUP>13</SUP>CS, H<SUB>2</SUB>S, OCS, and CH<SUB>3</SUB>OH, the simplest complex organic molecule (COM). The locations and kinematics suggest that these localized features are due to jet-driven shocks rather than being part of the hot-corino region encasing the protostar. The COM compositions of the molecular gas in these jet-localized regions are relatively simpler than those in the hot-corino zone. We speculate that this simplicity is due to either the liberation of ice with a less complex chemical history or the effects of shock chemistry. Our study highlights the dynamic interplay between the protostellar bipolar outflow, disk, inner-core environment, and the surrounding medium, contributing to our understanding of molecular complexity in solar-like young stellar objects.
• A Broadband X-Ray Investigation of Fast-spinning Intermediate Polar CTCV J2056–3014

  Columbia Astrophysics Laboratory, Columbia University, New York, NY 10027, USA;; South African Astronomical Observatory, P.O. Box 9, Observatory, 7935 Cape Town, South Africa; Department of Astronomy, University of Cape Town, Private Bag X3, Rondebosch 7701, South Africa;; Departamento de Física, Universidade Federal de Sergipe, Av. Marechal Rondon, S/N, 49100-000, São Cristóvão, SE, Brazil; Observatório Nacional, Rua Gal. José Cristino 77, 20921-400, Rio de Janeiro, RJ, Brazil;; Armagh Observatory and Planetarium, College Hill, Armagh, BT61 9DG, UK;; Department of Astronomy, University of Cape Town, Private Bag X3, Rondebosch 7701, South Africa;; Salcedo, Ciro; Mori, Kaya; Bridges, Gabriel; Hailey, Charles J.; Buckley, David A. H.; et al. (The Astrophysical Journal, 2024-11-01)

  We report on XMM-Newton, NuSTAR, and NICER X-ray observations of CTCV J2056–3014, a cataclysmic variable (CV) with one of the fastest-spinning white dwarfs (WDs) at P = 29.6 s. While previously classified as an intermediate polar, CJ2056 also exhibits the properties of WZ Sge–type CVs, such as dwarf novae and superoutbursts. With XMM-Newton and NICER, we detected the spin period up to ∼2 keV with 7σ significance. We constrained its derivative to <inline-formula> <mml:math overflow=scroll><mml:mo stretchy=false>|</mml:mo><mml:mrow><mml:mover><mml:mi>P</mml:mi><mml:mo>̇</mml:mo></mml:mover></mml:mrow><mml:mo stretchy=false>|</mml:mo><mml:mo>&lt;</mml:mo><mml:mn>1.8</mml:mn><mml:mo>×</mml:mo><mml:msup><mml:mrow><mml:mn>10</mml:mn></mml:mrow><mml:mrow><mml:mo>‑</mml:mo><mml:mn>12</mml:mn></mml:mrow></mml:msup></mml:math> </inline-formula> s s<SUP>‑1</SUP> after correcting for binary orbital motion. The pulse profile is characterized by a single broad peak with ∼25% modulation. NuSTAR detected a fourfold increase in unabsorbed X-ray flux coincident with an optical flare, in 2022 November. The XMM-Newton and NICER X-ray spectra at 0.310 keV are best characterized by an absorbed, optically thin three-temperature thermal plasma model (kT = 0.3, 1.0, and 4.9 keV), while the NuSTAR spectra at 3–30 keV are best fit by a single-temperature thermal plasma model (kT = 8.4 keV), both with Fe abundance Z <SUB>Fe</SUB>/Z <SUB>⊙</SUB> = 0.3. CJ2056 exhibits similarities to other fast-spinning CVs, such as low plasma temperatures and no significant X-ray absorption at low energies. As the WD's magnetic field strength is unknown, we applied both nonmagnetic and magnetic CV spectral models (MKCFLOW and MCVSPEC) to determine the WD mass. The derived WD mass range (M = 0.7–1.0 M <SUB>⊙</SUB>) is above the centrifugal breakup mass limit of 0.56 M <SUB>⊙</SUB> and consistent with the mean WD mass of local CVs (M ≈ 0.8–0.9 M <SUB>⊙</SUB>).

View more