Although the primary focus of astroinformatics is on the large worldwide distributed collection of digital astronomical databases, image archives, and research tools, the field recognizes the importance of legacy data sets as well—using modern technologies to preserve and analyze historical astronomical observations. Some Astroinformatics practitioners help to digitize historical and recent astronomical observations and images in a large database for efficient retrieval through web-based interfaces.[3][12] Another aim is to help develop new methods and software for astronomers, as well as to help facilitate the process and analysis of the rapidly growing amount of data in the field of astronomy.[13]
Astroinformatics is described as the "fourth paradigm" of astronomical research.[14] There are many research areas involved with astroinformatics, such as data mining, machine learning, statistics, visualization, scientific data management, and semantic science.[7] Data mining and machine learning play significant roles in astroinformatics as a scientific research discipline due to their focus on "knowledge discovery from data" (KDD) and "learning from data".[15][16]
The amount of data collected from astronomical sky surveys has grown from gigabytes to terabytes throughout the past decade and is predicted to grow in the next decade into hundreds of petabytes with the Large Synoptic Survey Telescope and into the exabytes with the Square Kilometre Array.[17] This plethora of new data both enables and challenges effective astronomical research. Therefore, new approaches are required. In part due to this, data-driven science is becoming a recognized academic discipline. Consequently, astronomy (and other scientific disciplines) are developing information-intensive and data-intensive sub-disciplines to an extent that these sub-disciplines are now becoming (or have already become) standalone research disciplines and full-fledged academic programs. While many institutes of education do not boast an astroinformatics program, such programs most likely will be developed in the near future.
Informatics has been recently defined as "the use of digital data, information, and related services for research and knowledge generation". However the usual, or commonly used definition is "informatics is the discipline of organizing, accessing, integrating, and mining data from multiple sources for discovery and decision support." Therefore, the discipline of astroinformatics includes many naturally-related specialties including data modeling, data organization, etc. It may also include transformation and normalization methods for data integration and information visualization, as well as knowledge extraction, indexing techniques, information retrieval and data mining methods. Classification schemes (e.g., taxonomies, ontologies, folksonomies, and/or collaborative tagging[18]) plus Astrostatistics will also be heavily involved. Citizen science projects (such as Galaxy Zoo) also contribute highly valued novelty discovery, feature meta-tagging, and object characterization within large astronomy data sets. All of these specialties enable scientific discovery across varied massive data collections, collaborative research, and data re-use, in both research and learning environments.
In 2007, the Galaxy Zoo project[19] was launched for morphological classification[20][21] of a large number of galaxies. In this project, 900,000 images were considered for classification that were taken from the Sloan Digital Sky Survey (SDSS)[22] for the past 7 years. The task was to study each picture of a galaxy, classify it as elliptical or spiral, and determine whether it was spinning or not. The team of Astrophysicists led by Kevin Schawinski in Oxford University were in charge of this project and Kevin and his colleague Chris Linlott figured out that it would take a period of 3–5 years for such a team to complete the work.[23] There they came up with the idea of using Machine Learning and Data Science techniques for analyzing the images and classifying them.[24]
In 2012, two position papers[25][26] were presented to the Council of the American Astronomical Society that led to the establishment of formal working groups in astroinformatics and Astrostatistics for the profession of astronomy within the US and elsewhere.[27]
Astroinformatics provides a natural context for the integration of education and research.[28] The experience of research can now be implemented within the classroom to establish and grow data literacy through the easy re-use of data.[29] It also has many other uses, such as repurposing archival data for new projects, literature-data links, intelligent retrieval of information, and many others.[30]
Methodology
The data retrieved from the sky surveys are first brought for data preprocessing. In this, redundancies are removed and filtrated. Further, feature extraction is performed on this filtered data set, which is further taken for processes.[31] Some of the renowned sky surveys are listed below:
The size of data from the above-mentioned sky surveys ranges from 3 TB to almost 4.6 EB.[31] Further, data mining tasks that are involved in the management and manipulation of the data involve methods like classification, regression, clustering, anomaly detection, and time-series analysis. Several approaches and applications for each of these methods are involved in the task accomplishments.
Classification
Classification[40] is used for specific identifications and categorizations of astronomical data such as Spectral classification, Photometric classification, Morphological classification, and classification of solar activity. The approaches of classification techniques are listed below:
Regression[41] is used to make predictions based on the retrieved data through statistical trends and statistical modeling. Different uses of this technique are used for fetching Photometric redshifts and measurements of physical parameters of stars.[42] The approaches are listed below:
Anomaly detection[45] is used for detecting irregularities in the dataset. However, this technique is used here to detect rare/special objects. The following approaches are used:
Time-Series analysis[46] helps in analyzing trends and predicting outputs over time. It is used for trend prediction and novel detection (detection of unknown data). The approaches used here are:
^Borne, Kirk (2000). "Science User Scenarios for a Virtual Observatory Design Reference Mission: Science Requirements for Data Mining". arXiv:astro-ph/0008307.
^Borne, Kirk (2008). "Scientific Data Mining in Astronomy". In Kargupta, Hillol; et al. (eds.). Next generation of data mining. London: CRC Press. pp. 91–114. ISBN9781420085860.
^Borne, Kirk D (2003). "Distributed data mining in the National Virtual Observatory". In Dasarathy, Belur V (ed.). Data Mining and Knowledge Discovery: Theory, Tools, and Technology V. Vol. 5098. pp. 211–218. doi:10.1117/12.487536. S2CID28195520.
^Borne, Kirk (2009). "Astroinformatics: A 21st Century Approach to Astronomy". Astro2010: The Astronomy and Astrophysics Decadal Survey. 2010: P6. arXiv:0909.3892. Bibcode:2009astro2010P...6B.
^"Online Science". Talks by Jim Gray. Microsoft Research. Retrieved 11 January 2015.
^Borne, K; Becla, J; Davidson, I; Szalay, A; Tyson, J. A; Bailer-Jones, Coryn A.L (2008). "The LSST Data Mining Research Agenda". AIP Conference Proceedings. pp. 347–351. arXiv:0811.0167. doi:10.1063/1.3059074. S2CID118399971.
^Ivezić, Ž; Axelrod, T; Becker, A. C; Becla, J; Borne, K; Burke, D. L; Claver, C. F; Cook, K. H; Connolly, A; Gilmore, D. K; Jones, R. L; Jurić, M; Kahn, S. M; Lim, K.-T; Lupton, R. H; Monet, D. G; Pinto, P. A; Sesar, B; Stubbs, C. W; Tyson, J. A; Bailer-Jones, Coryn A.L (2008). "Parametrization and Classification of 20 Billion LSST Objects: Lessons from SDSS". AIP Conference Proceedings. Vol. 1082. pp. 359–365. arXiv:0810.5155. doi:10.1063/1.3059076. S2CID117914490. {{cite book}}: |journal= ignored (help)
^Baron, Dalya (2019-04-15), Machine Learning in Astronomy: a practical overview, arXiv:1904.07248
^Borne, Kirk. "Astroinformatics in a Nutshell". asaip.psu.edu. The Astrostatistics and Astroinformatics Portal, Penn State University. Retrieved 11 January 2016.
^Feigelson, Eric. "Astrostatistics in a Nutshell". asaip.psu.edu. The Astrostatistics and Astroinformatics Portal, Penn State University. Retrieved 11 January 2016.
^Feigelson, E.; Ivezić, Ž.; Hilbe, J.; Borne, K. (2013). "New Organizations to Support Astroinformatics and Astrostatistics". Astronomical Data Analysis Software and Systems Xxii. 475: 15. arXiv:1301.3069. Bibcode:2013ASPC..475...15F.
^Borne, Kirk (2009). "The Revolution in Astronomy Education: Data Science for the Masses". Astro2010: The Astronomy and Astrophysics Decadal Survey. 2010: P7. arXiv:0909.3895. Bibcode:2009astro2010P...7B.
^"Using Data in the Classroom". Science Education Resource Center at Carleton College. National Science Digital Library. Retrieved 11 January 2016.
^Sarstedt, Marko; Mooi, Erik (2014), Sarstedt, Marko; Mooi, Erik (eds.), "Regression Analysis", A Concise Guide to Market Research: The Process, Data, and Methods Using IBM SPSS Statistics, Berlin, Heidelberg: Springer, pp. 193–233, doi:10.1007/978-3-642-53965-7_7, ISBN978-3-642-53965-7, retrieved 2024-05-10