@article{discovery1465830,
          volume = {444},
           month = {November},
            note = {This article has been accepted for publication in Monthly Notices of the Royal Astronomical Society (MNRAS) {\copyright}: 2014 The Authors Published by Oxford University Press on behalf of the Royal Astronomical Society. All rights reserved.},
           pages = {3230 -- 3257},
            year = {2014},
           title = {The second data release of the INT Photometric Ha Survey of the Northern Galactic Plane (IPHAS DR2)},
         journal = {MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY},
          number = {4},
        keywords = {Catalogues, Surveys, Stars: emission-line, Be, Galaxy: stellar content},
        abstract = {The INT/WFC Photometric H{\ensuremath{\alpha}} Survey of the Northern Galactic Plane (IPHAS) is a 1800 deg2 imaging survey covering Galactic latitudes {\ensuremath{|}}b{\ensuremath{|}} {\ensuremath{<}} 5o and longitudes ? = 30o-215o in the r, i, and H{\ensuremath{\alpha}} filters using the Wide Field Camera (WFC) on the 2.5-m Isaac Newton Telescope (INT) in La Palma. We present the first quality-controlled and globally calibrated source catalogue derived from the survey, providing single-epoch photometry for 219 million unique sources across 92 per cent of the footprint. The observations were carried out between 2003 and 2012 at a median seeing of 1.1 arcsec (sampled at 0.33 arcsec pixel?1) and to a mean 5{\ensuremath{\sigma}} depth of 21.2 (r), 20.0 (i), and 20.3 (H{\ensuremath{\alpha}}) in the Vega magnitude system. We explain the data reduction and quality control procedures, describe and test the global re-calibration, and detail the construction of the new catalogue. We show that the new calibration is accurate to 0.03 mag (root mean square) and recommend a series of quality criteria to select accurate data from the catalogue. Finally, we demonstrate the ability of the catalogue's unique (r ? H{\ensuremath{\alpha}}, r ? i) diagram to (i) characterize stellar populations and extinction regimes towards different Galactic sightlines and (ii) select and quantify H{\ensuremath{\alpha}} emission-line objects. IPHAS is the first survey to offer comprehensive CCD photometry of point sources across the Galactic plane at visible wavelengths, providing the much-needed counterpart to recent infrared surveys.},
             url = {http://dx.doi.org/ 10.1093/mnras/stu1651},
          author = {Barentsen, G and Farnhill, HJ and Drew, JE and Gonzalez-Solares, EA and Greimel, R and Irwin, MJ and Miszalski, B and Ruhland, C and Groot, P and Mampaso, A and Sale, SE and Henden, AA and Aungwerojwit, A and Barlow, MJ and Carter, PJ and Corradi, RLM and Drake, JJ and Eisloeffel, J and Fabregat, J and Gaensicke, BT and Fusillo, NPG and Greiss, S and Hales, AS and Hodgkin, S and Huckvale, L and Irwin, J and King, R and Knigge, C and Kupfer, T and Lagadec, E and Lennon, DJ and Lewis, JR and Mohr-Smith, M and Morris, RAH and Naylor, T and Parker, QA and Phillipps, S and Pyrzas, S and Raddi, R and Roelofs, GHA and Rodriguez-Gil, P and Sabin, L and Scaringi, S and Steeghs, D and Suso, J and Tata, R and Unruh, YC and van Roestel, J and Viironen, K and Vink, JS and Walton, NA and Wright, NJ and Zijlstra, AA},
            issn = {0035-8711}
}