New Nebulae shown on Franklin-Adams Chart Plates.

By P. J. Melotte. (Plate 15.)

The following nebulae, which do not appear to have been recorded elsewhere, were noted when drawing up the Catalogue of Star Clusters shown on Franklin-Adams Charts Plates. They were also independently noted by Dr. Lundmark when examining the same plates. The positions given are for the epoch 1900.0.

Plate 15

Extended Nebula in Vela.
Centre (1900.0) R.A. 8^h 31^m. Dec. −44° 20′.
(1 reseau interval is equal to 1°.)

R.A. 5^h 15^m.9 Dec. +8° 13′

Diffuse nebula on south preceding side of B.D. +8°, 933 (mag. 6.5) with which it appears to be associated. The brightest part is roughly pear-shaped, with the pointed end in the direction of the star. There is a noticeable falling-off in star density in the area surrounding the nebula, particularly to the south-west, where there is a strongly marked vacant space over one degree square. A fifteenth magnitude star is near the centre of the brightest part of the nebula, approximately 5′ west and 4′ south of B.D. 8°,933. The nebula is well shown on F.A. Chart 121, where it falls near the edge of the plate, and it also appears on Chart 97, but somewhat fainter. The fact that this nebula has not been noted before might be explained if it proved to be variable.

R.A. 8^h 30^m. Dec. −44° 0′. (See Plate 15.)

Large extended nebula in Vela. The nebula lies between R.A. 8^h 22^m and 8^h 39^m, and extends from Dec. −42° 0′ to −46° 30′. It consists of a number of bright nebulous streaks, some of the brightest of which outline an area, seven square degrees in extent, roughly oval in form. The brightest part lies between the two stars at α 8^h 26^m.0, δ −44° 23′ (mag. 5.1) and α 8^h 34^m.2, δ −42° 38′ (mag. 4.1), e Velorum, where there are several branches of the nebula. There is much bright diffuse nebula to the south of the area indicated by the limits given above, but its appearance on the plate is confused by the densely crowded star-field. A number of stars in the region are nebulous or show traces of nebulosity near them, of which the following may be noted :–

* N.G.C. 2626.

The magnitudes and numbers are from the Cape Photographic Durchmusterung.

R.A. 11^h 5.3^m. Dec. −77° 7′.

Nebulous star surrounded with bright nebula (C.P.D. −76°, 654, mag. 8.5). Falls near centre of a vacant area 2.2 square degrees in extent. There is a small patch of nebula near a twelfth magnitude star at α 11^h 3^m, δ −76° 48′. A bright nebula (H.A., lx. 6, p. 161, No. 352) is at the northern end of the vacant area. The obscuration is well defined amongst the surrounding star-field and contains some traces of faint nebulosity in addition to those given above.

R.A. 23^h 56^m.9. Dec. −15° 59′.

Faint nebula, 10′ x 2′.5. A faint star (mag. 15.5) is at the centre, and another star (mag. 16) falls at the southern edge. The nebula is condensed towards the centre, and the southern half appears brighter than the northern. The star distribution in the surrounding area is irregular, the region on the following side being almost devoid of stars. The appearance of this nebula and of Barnard's Nebula, N.G.C. 6822, is strikingly similar on the plates. The galactic co-ordinates are: Long. 47°, Lat. −74°.