Examples of data access are given, including a cross-matching of IPHAS photometry with sources in the UKIDSS Galactic Plane Survey that validates the existing calibration of the best data. The IDR represents the largest data set published primarily through VO interfaces to date, and so stands as an exemplar of the future of survey data mining. Access through the AstroGrid VO Desktop opens up the full range of analysis options, and allows full integration with the wider range of data and services available through the Virtual Observatory. Simple traditional web access is provided to the main IPHAS photometric catalogue, in addition to a number of common catalogues (such as 2MASS) which are of immediate relevance. We note how access to the primary data products has been implemented through use of standard virtual observatory publishing interfaces. In this paper we present the IPHAS Initial Data Release, primarily a photometric catalogue of about 200 million unique objects, coupled with associated image data covering about 1600 deg2 in three passbands. Mapping emission line objects enables a particular focus on objects in the young and old stages of stellar evolution ranging from early T-Tauri stars to late planetary nebulae. The survey is aimed at revealing the large scale organization of the Milky Way and can be applied to identifying a range of stellar populations within it. The INT/WFC Photometric Hα Survey of the Northern Galactic Plane (IPHAS) is an imaging survey being carried out in Hα, r′ and i′ filters, with the Wide Field Camera (WFC) on the 2.5-m Isaac Newton Telescope (INT) to a depth of r′= 20 (10σ). Such assumptions, though ultimately abandoned, would lead Herschel in the 1830s to advance the possibility that the dim companion stars in certain double star pairs were not stars at all but in fact planets. In practice, classification of a specific double star pair into one of these categories was based on the assumption that stars were of approximately the same luminosity and thus differences in relative brightness between stars were caused by difference in distances. Optical doubles were useful in determining parallax while binary doubles were not. For Herschel, a major consideration in double star astronomy was distinguishing between types of double stars. In particular, an analysis of John Herschel's early work on double stars illustrates the way in which speculations regarding these objects were shaped by assumptions of the properties of stars themselves. The work of the British astronomer John Herschel, however, shows that questions regarding the physical nature of double stars were also important. Previous research on the origins of double star astronomy in the early nineteenth century emphasized the role mathematical methods and instrumentation played in motivating early observations of these objects.
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