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Using spectroscopic observations at relatively high resolution (Δλ ≡ 0.35 Å) in the region within 30 arcseconds of the nucleus of NGC 6946 the authors have found clear evidence of a strong expansion, with velocities of order 100 km s-1. By comparison with intensity maps in H I (21 cm) H2 (CO 2.6 mm) and Hα taken from the literature the authors

The authors have mapped the nearby flocculent spiral galaxy in the visible U, B and V bands, as well as in the near infrared J, H and K bands, with a linear resolution of 900 pc. The galaxy is found to have two principal current centres of large-scale star formation, signposted by centres of ultraviolet and blue flux. One is in the nucleus, defined

The paper presents isophotal maps of the distribution of the flux emitted by transitions of various molecular species in the spectrum of Comet Halley at a heliocentric distance of 1.92 AU, after perihelion. The observations were made at the Observatorio del Roque de los Muchachos, in La Palma, using the RGO Image Photon Counting System attached to

New optical and infrared spectroscopic and photometric observations of the cometary nebula 1548C27 have shown that a young star loosing mass at high velocity (hundreds of km 1) is the source of energy of the nebula. This source is suggested from its infrared luminosity, to be a Herbig Ae-Be type star surrounded by a dusty envelope radiating at a

New bidimensional spectroscopic observations of A78 allow the authors to determine the He, O, Ne, and N abundances and their variations along the nebula. A clear overabundance of these elements is found in the central region of the nebula, suggesting different nebular ejections of material processed in the stellar interior and dredged-up