A deep catalogue of classical Be stars in the direction towards the Perseus Arm : spectral types and interstellar reddenings

Abstract

We present a catalogue of 247 photometrically and spectroscopically confirmed fainter classical Be stars (13 ≲ r ≲ 16) in the direction of the Perseus Arm of the Milky Way (−1° < b < +4°, 120° < ℓ < 140°). The catalogue consists of 181 IPHAS-selected new classical Be stars, in addition to 66 objects that we studied in our previous work more closely, and three stars identified as classical Be stars in earlier work. This study more than doubles the number known in the region. Photometry spanning 0.6–5 μm, spectral types, and interstellar reddenings are given for each object. The spectral types were determined from low-resolution spectra (λ/Δλ ≈ 800–2000), to a precision of 1–3 subtypes. The interstellar reddenings are derived from the (r − i) colour, using a method that corrects for circumstellar disc emission. The colour excesses obtained range from E(B − V) = 0.3 up to 1.6 – a distribution that modestly extends the range reported in the literature for Perseus-Arm open clusters. For around half the sample, the reddenings obtained are compatible with measures of the total sightline Galactic extinction. Many of these are likely to lie well beyond the Perseus Arm