Please wait, while we are loading the content...
Please wait, while we are loading the content...
| Content Provider | Springer Nature Link |
|---|---|
| Author | Farcchia, D. Chesley, S. R. Tholen, D. J. Micheli, M. |
| Copyright Year | 2014 |
| Abstract | In November 2004 radar delay measurements of near-Earth asteroid (3908) Nyx obtained at the Arecibo radio telescope turned out to be $$7.5\sigma $$ away from the orbital prediction. We prove that this discrepancy was caused by a poor astrometric treatment and an incomplete dynamical model, which did not account for nongravitational perturbations. To improve the astrometric treatment, we remove known star catalog biases, apply suitable weights to the observations, and use an aggressive outlier rejection scheme. The main issue related to the dynamical model is having not accounted for the Yarkovsky effect. Including the Yarkovsky perturbation in the model makes the orbital prediction and the radar measurements statistically consistent by both reducing the offset and increasing the prediction uncertainty to a more realistic level. This analysis shows the sensitivity of high precision predictions to the astrometric treatment and the Yarkovsky effect. By using the full observational dataset we obtain a $$5\sigma $$ detection of the Yarkovsky effect acting on Nyx corresponding to an orbital drift $$da/dt = (142 \pm 29)$$ m/year. In turn, we derive constraints on thermal inertia and bulk density. In particular, we find that the bulk density of Nyx is around 1 g/cm $$^3$$ , possibly less. To make sure that our results are not corrupted by an asteroid impact or a close approach with a perturbing asteroid not included in our dynamical model, we show that the astrometry provides no convincing evidence of an impulsive variation of Nyx’s velocity while crossing the main belt region. |
| Starting Page | 301 |
| Ending Page | 312 |
| Page Count | 12 |
| File Format | |
| ISSN | 09232958 |
| Journal | Celestial Mechanics and Dynamical Astronomy |
| Volume Number | 119 |
| Issue Number | 3-4 |
| e-ISSN | 15729478 |
| Language | English |
| Publisher | Springer Netherlands |
| Publisher Date | 2014-02-14 |
| Publisher Place | Dordrecht |
| Access Restriction | One Nation One Subscription (ONOS) |
| Subject Keyword | Astrometric treatment Orbit determination Asteroids Yarkovsky effect Orbital drift Astrophysics and Astroparticles Dynamical Systems and Ergodic Theory Aerospace Technology and Astronautics Geophysics/Geodesy Mechanics |
| Content Type | Text |
| Resource Type | Article |
| Subject | Applied Mathematics Mathematical Physics Astronomy and Astrophysics Modeling and Simulation Computational Mathematics Space and Planetary Science |
National Digital Library of India (NDLI) is a virtual repository of learning resources which is not just a repository with search/browse facilities but provides a host of services for the learner community. It is sponsored and mentored by Ministry of Education, Government of India, through its National Mission on Education through Information and Communication Technology (NMEICT). Filtered and federated searching is employed to facilitate focused searching so that learners can find the right resource with least effort and in minimum time. NDLI provides user group-specific services such as Examination Preparatory for School and College students and job aspirants. Services for Researchers and general learners are also provided. NDLI is designed to hold content of any language and provides interface support for 10 most widely used Indian languages. It is built to provide support for all academic levels including researchers and life-long learners, all disciplines, all popular forms of access devices and differently-abled learners. It is designed to enable people to learn and prepare from best practices from all over the world and to facilitate researchers to perform inter-linked exploration from multiple sources. It is developed, operated and maintained from Indian Institute of Technology Kharagpur.
Learn more about this project from here.
NDLI is a conglomeration of freely available or institutionally contributed or donated or publisher managed contents. Almost all these contents are hosted and accessed from respective sources. The responsibility for authenticity, relevance, completeness, accuracy, reliability and suitability of these contents rests with the respective organization and NDLI has no responsibility or liability for these. Every effort is made to keep the NDLI portal up and running smoothly unless there are some unavoidable technical issues.
Ministry of Education, through its National Mission on Education through Information and Communication Technology (NMEICT), has sponsored and funded the National Digital Library of India (NDLI) project.
| Sl. | Authority | Responsibilities | Communication Details |
|---|---|---|---|
| 1 | Ministry of Education (GoI), Department of Higher Education |
Sanctioning Authority | https://www.education.gov.in/ict-initiatives |
| 2 | Indian Institute of Technology Kharagpur | Host Institute of the Project: The host institute of the project is responsible for providing infrastructure support and hosting the project | https://www.iitkgp.ac.in |
| 3 | National Digital Library of India Office, Indian Institute of Technology Kharagpur | The administrative and infrastructural headquarters of the project | Dr. B. Sutradhar bsutra@ndl.gov.in |
| 4 | Project PI / Joint PI | Principal Investigator and Joint Principal Investigators of the project |
Dr. B. Sutradhar bsutra@ndl.gov.in Prof. Saswat Chakrabarti will be added soon |
| 5 | Website/Portal (Helpdesk) | Queries regarding NDLI and its services | support@ndl.gov.in |
| 6 | Contents and Copyright Issues | Queries related to content curation and copyright issues | content@ndl.gov.in |
| 7 | National Digital Library of India Club (NDLI Club) | Queries related to NDLI Club formation, support, user awareness program, seminar/symposium, collaboration, social media, promotion, and outreach | clubsupport@ndl.gov.in |
| 8 | Digital Preservation Centre (DPC) | Assistance with digitizing and archiving copyright-free printed books | dpc@ndl.gov.in |
| 9 | IDR Setup or Support | Queries related to establishment and support of Institutional Digital Repository (IDR) and IDR workshops | idr@ndl.gov.in |
|
Loading...
|