From the Centaurs to the Inner Oort Cloud: Exploring the Kuiper belt Connection
Lead Research Organisation:
Queen's University Belfast
Department Name: Sch of Mathematics and Physics
Abstract
The small bodies of the Outer Solar System are the material leftover from the construction of the planets and serve as a fossil record of the Solar System's history. These planetesimals can be broadly divided in the Centaurs, the Kuiper belt, and the Inner Oort cloud. The Kuiper belt consists of orbits beyond Neptune residing between approximately 30-250 au. Centaurs are cometary precursors that have recently diffused out of the Kuiper belt. These bodies are a transitory population on relatively short-lived chaotic orbits between Neptune and Jupiter that cross one or more of the giant-planets. The Inner Oort cloud on the other hand consists of dynamically excited and detached orbits from Neptune, with semimajor axes greater than ~ 250 au, likely scattered on to their orbits by a giant planet beyond Neptune or by a passing star.
By studying the ensemble properties (shapes, sizes, compositions, orbits, and other physical characteristics) of these small icy planetesimals, we can probe the giant planets' early dynamical history, explore the compositional structure of the Solar System's primordial planetesimal disk, and study the evolution of the outer Solar System over time. The majority of these objects are too faint for spectroscopy with ground-based telescopes, but by measuring broad-band colors in different optical and near-infrared filters, we obtain a proxy for a planetesimal's surface composition. By measuring the brightness of a planetesimal over time, we can estimate shape and measure rotation rates. With deep optical imaging, we can look for faint features associated with comet-like activity and explore how often these objects experience outgassing of water ice and other volatile species.
The main aim of this project is to explore the connection and evolutionary history of the Centaurs, Kuiper belt, and Inner Oort cloud. The project will focus on two main avenues for exploring these Solar System populations. The first will be through the study of light curves, phase curves, and the cometary activity histories of a sample of KBOs and Centaurs utilising observations from 1-8-m telescopes and the Asteroid Terrestrial-impact Last Alert System (ATLAS). The second avenue will consist of a search for distant inner Oort Cloud objects with the ATLAS survey in order to constrain the size and bright-end magnitude distribution of this distant population of bodies.
By studying the ensemble properties (shapes, sizes, compositions, orbits, and other physical characteristics) of these small icy planetesimals, we can probe the giant planets' early dynamical history, explore the compositional structure of the Solar System's primordial planetesimal disk, and study the evolution of the outer Solar System over time. The majority of these objects are too faint for spectroscopy with ground-based telescopes, but by measuring broad-band colors in different optical and near-infrared filters, we obtain a proxy for a planetesimal's surface composition. By measuring the brightness of a planetesimal over time, we can estimate shape and measure rotation rates. With deep optical imaging, we can look for faint features associated with comet-like activity and explore how often these objects experience outgassing of water ice and other volatile species.
The main aim of this project is to explore the connection and evolutionary history of the Centaurs, Kuiper belt, and Inner Oort cloud. The project will focus on two main avenues for exploring these Solar System populations. The first will be through the study of light curves, phase curves, and the cometary activity histories of a sample of KBOs and Centaurs utilising observations from 1-8-m telescopes and the Asteroid Terrestrial-impact Last Alert System (ATLAS). The second avenue will consist of a search for distant inner Oort Cloud objects with the ATLAS survey in order to constrain the size and bright-end magnitude distribution of this distant population of bodies.
Organisations
Studentship Projects
| Project Reference | Relationship | Related To | Start | End | Student Name |
|---|---|---|---|---|---|
| ST/V506990/1 | 01/10/2020 | 30/09/2024 | |||
| 2439884 | Studentship | ST/V506990/1 | 01/10/2020 | 31/03/2024 | Matthew Dobson |
| Description | Analysis of data from the wide-field Asteroid Terrestrial-impact Last Alert System (ATLAS) astronomical survey has allowed us to study the phase curves of several small Solar System objects with more data than ever before. Phase curves quantify how the brightness of these objects change with the angle relative to the direction of sunlight at which they are viewed and allow us to probe the surface properties of these distant objects. The unprecedentedly large datasets allowed us to disprove the existence of dimming of certain objects with smaller phase angle which was reported by previous studies of phase curves and which ran contrary to physical theories of light reflectance. Furthermore, analysis of these objects' phase curves have allowed us to detect instances of cometary activity in populations of small Solar System objects which would otherwise remain undetected in direct observations of these objects. |
| Exploitation Route | The detection of cometary activity exhibited by small Solar System objects from their phase curves alone shows that future wide-field astronomical surveys such as the Rubin Observatory Legacy Survey of Space and Time (LSST) will be able to detect cometary activity in the same way, as this survey is predicted to accumulate similar sizes of dataset to those from ATLAS. LSST will thus build on what ATLAS has already discovered by observing to fainter brightnesses, allowing detection of cometary activity by even fainter objects at even greater distances from the Sun. This will prove valuable in understanding cometary activity in the Solar System |
| Sectors | Digital/Communication/Information Technologies (including Software),Education |
| Description | Queen's University Belfast Astronomy Day for Northern Ireland Science Festival |
| Form Of Engagement Activity | A talk or presentation |
| Part Of Official Scheme? | No |
| Geographic Reach | Regional |
| Primary Audience | Undergraduate students |
| Results and Impact | Several members of the public, all displaying an interest in astronomy, attended a question-and-answer session as part of the Astronomy Day held by Queen's University Belfast for the Northern Ireland Science Festival on 25th February 2023. I chaired the question-and-answer session between the audience members and three researchers from the Astrophysics Research Centre. Details about what it is like to work in astrophysics research were discussed. After the session, it was reported that several of the attendees were now considering a career in astrophysics at Queen's University Belfast. |
| Year(s) Of Engagement Activity | 2023 |