No Arabic abstract
Amateur contributions to professional publications have increased exponentially over the last decades in the field of Planetary Astronomy. Here we review the different domains of the field in which collaborations between professional and amateur astronomers are effective and regularly lead to scientific publications. We discuss the instruments, detectors, softwares and methodologies typically used by amateur astronomers to collect the scientific data in the different domains of interest. Amateur contributions to the monitoring of planets and interplanetary matter, characterization of asteroids and comets, as well as the determination of the physical properties of Kuiper Belt Objects and exoplanets are discussed.
The observation of gaseous giant planets is of high scientific interest. Although they have been the targets of several spacecraft missions, there still remains a need for continuous ground-based observations. As their atmospheres present fast dynamic environments on various time scales, the availability of time at professional telescopes is neither uniform nor of sufficient duration to assess temporal changes. However, numerous amateurs with small telescopes (of 15-40 cm) and modern hardware and software equipment can monitor these changes daily (within the 360-900nm range). Amateurs are able to trace the structure and the evolution of atmospheric features, such as major planetary-scale disturbances, vortices, and storms. Their observations provide a continuous record and it is not uncommon to trigger professional observations in cases of important events, such as sudden onset of global changes, storms and celestial impacts. For example, the continuous amateur monitoring has led to the discovery of fireballs in Jupiters atmosphere, providing information not only on Jupiters gravitational influence but also on the properties and populations of the impactors. Photometric monitoring of stellar occultations by the planets can reveal spatial/temporal variability in their atmospheric structure. Therefore, co-ordination and communication between professionals and amateurs is important. We present examples of such collaborations that: (i) engage systematic multi-wavelength observations and databases, (ii) examine the variability of cloud features over timescales from days to decades, (iii) provide, by ground-based professional and amateur observations, the necessary spatial and temporal resolution of features that will be studied by the interplanetary mission Juno, (iv) investigate video observations of Jupiter to identify impacts of small objects, (v) carry out stellar-occultation campaigns.
Since the CCD technique became financially reachable for amateur astronomers, they can cover topics of professional science. Mainly in the time-domain astronomy, such as variable star research, their help is invaluable. We focus on cooperation between amateur and professional astronomers in the Czech Republic, give some examples of successful projects and propose new programs that can benefit from such cooperation and bring high-quality results.
Planetary radars have obtained unique science measurements about solar system bodies and they have provided orbit determinations allowing spacecraft to be navigated throughout the solar system. Notable results have been on Venus, Earths twin, and small bodies, which are the constituents of the Suns debris disk. Together, these results have served as ground truth from the solar system for studies of extrasolar planets. The Nations planetary radar infrastructure, indeed the worlds planetary radar infrastructure, is based on astronomical and deep space telecommunications infrastructure, namely the radar transmitters at the Arecibo Observatory and the Goldstone Solar System Radar, part of NASAs Deep Space Network, along with the Green Bank Telescope as a receiving element. This white paper summarizes the state of this infrastructure and potential technical developments that should be sustained in order to enable continued studies of solar system bodies for comparison and contrast with extrasolar planetary systems. Because the planetary radar observations leverage existing infrastructure largely developed for other purposes, only operations and maintenance funding is required, though modest investments could yield more reliable systems; in the case of the Green Bank Telescope, additional funding for operations is required.
BeSS is a database containing a catalogue of Be stars and their spectra, set up more than 10 years ago as a collaboration between professional and amateur astronomers. It currently contains over 177000 spectra of 2340 stars, provided by ~150 different observers. Its continuous success has already led to the use of BeSS data in more than 70 scientific papers.
This review outlines concepts of mathematical statistics, elements of probability theory, hypothesis tests and point estimation for use in the analysis of modern astronomical data. Least squares, maximum likelihood, and Bayesian approaches to statistical inference are treated. Resampling methods, particularly the bootstrap, provide valuable procedures when distributions functions of statistics are not known. Several approaches to model selection and good- ness of fit are considered. Applied statistics relevant to astronomical research are briefly discussed: nonparametric methods for use when little is known about the behavior of the astronomical populations or processes; data smoothing with kernel density estimation and nonparametric regression; unsupervised clustering and supervised classification procedures for multivariate problems; survival analysis for astronomical datasets with nondetections; time- and frequency-domain times series analysis for light curves; and spatial statistics to interpret the spatial distributions of points in low dimensions. Two types of resources are presented: about 40 recommended texts and monographs in various fields of statistics, and the public domain R software system for statistical analysis. Together with its sim 3500 (and growing) add-on CRAN packages, R implements a vast range of statistical procedures in a coherent high-level language with advanced graphics.