We present near-IR colour--magnitude diagrams and star counts for a number of regions along the Galactic plane. It is shown that along the l=27 b=0 line of sight there is a feature at 5.7 +-0.7kpc with a density of stars at least a factor two and probably more than a factor five times that of the disc at the same position. This feature forms a distinct clump on an H vs. J-H diagram and is seen at all longitudes from the bulge to about l=28, but at no longitude greater than this. The distance to the feature at l=20 is about 0.5kpc further than at l=27 and by l=10 it has merged with, or has become, the bulge. Given that at l=27 and l=21 there is also a clustering of very young stars, the only component that can reasonably explain what is seen is a bar with half length of around 4kpc and a position angle of about 43+-7.Comment: 5 pages, 5 figures accepted as a letter in MNRA

Context. Over the last decade a series of results have lent support to the hypothesis of the existence of a long thin bar in the Milky Way with a half-length of 4.5 kpc and a position angle of around 45• . This is apparently a very different structure from the triaxial bulge of the Galaxy. Aims. In this paper, we analyse the stellar distribution in the inner 4 kpc of the Galaxy to see if there is clear evidence for two triaxial or barlike structures, or whether there is only one. Methods. By using the red-clump population as a tracer of the structure of the inner Galaxy we determine the apparent morphology of the inner Galaxy. Star counts from 2MASS are used to provide additional support for this analysis. Results. We show that there are two very different large-scale triaxial structures coexisting in the inner Galaxy: a long thin stellar bar constrained to the Galactic plane (|b| < 2• ) with a position angle of 43.• 0 ± 1.• 8, and a distinct triaxial bulge that extends to at least |b| ≤ 7.5• with a position angle of 12.• 6 ± 3.• 2. The scale height of the bar source distribution is around 100 pc, whereas for the bulge the value of this parameter is five times larger.

Recent GLIMPSE data have further confirmed the hypothesis of the existence of an in-plane long bar different from the bulge of the Milky Way with the same characteristics as emphasized some years ago by our team. In this paper, we present two new analyses that corroborate recent and earlier claims concerning the existence in our Galaxy of a long flat bar with approximate dimensions 7.8 kpc ×1.2 kpc ×0.2 kpc and a position angle of approximately 43 • : 1) star counts with 2MASS All-Sky Release and MSX data, which give an excess in the plane region along 0 < l < 30 • compared with −30 • < l < 0, and which cannot be due to the bulge, spiral arms, a ring, or extinction; 2) new data on the distance of the long bar using the red clump method, together with recent observations of our own that are compared with our model, and that are in agreement with the long-bar scenario.

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Abstract. New evidence for a long thin Galactic bar (in contradistinction to the bulge), as well as for the existence of the ring and the truncation of the inner disc, are sought in the DENIS survey. First, we examine DENIS and Two Micron Galactic Survey star counts for the characteristic signatures of an in-plane bar and ring. The star counts in the plane for 30• > l > −30• are shown to be highly asymmetric with considerably more sources at positive than at negative longitudes. At |b| ≈ 1.5• , however, the counts are nearly symmetric. Therefore, the asymmetry is not due to the disc, which is shown to have an inner truncation, or to the bulge, so there has to be another major component in the inner Galaxy that is causing the asymmetries. This component provides up to 50% of the detected sources in the plane between the bulge and l = 27• or l = −14• . This component is shown to be consistent with an in-plane bar with a position angle of 40• and half-length of 3.9 kpc. However, there is also a major peak in the counts at l = −22• , which coincides with the tangential point of the so-called 3 kpc arm. This is shown to be most probably a ring or a pseudo-ring. The extinction in the plane is also shown to be asymmetric with more extinction at negative than at positive longitudes. For l < 8• the extinction is shown to be slightly tilted with respect to b = 0• in the same manner as the HI disc. We conclude that the Galaxy is a fairly typical ringed barred spiral galaxy.