NGC 1807

Historical observations

NGC/IC Dreyer (1888, 1895, 1908)

Described in the NGC as "pretty rich cluster of large and small stars".

Published comments

Melotte, P.J. (1915)

A catalogue of star clusters shown on Franklin-Adams chart plates. Mem.R.A.S., 60(5), 175-186.

Raab, S. (1922)

Raab, S. (1922) A research on open clusters. Lund Medd. Astron. Obs. Ser. II, 28, 1.

Discussed, based of F-A plates.

Doig, P. (1926)

Doig, P. (1926) "A Catalogue of Estimated Parallaxes of 112 Nebulae, Open clusters and Star Groups", Vol 36 (4), p 107-115.

"thin irregular cluster in rich region." He gives the approx. diameter as 17 arcmin.

Trumpler, R.J. (1928)

(Lick Obs Bul, Vol 14, No. 420) gives the diameter as 14' and the class as 1 2 p. He notes: "The cluster Melotte 29 should undoubtdely be indentified with NGC 1817 and not with NGC 1807."

He described this cluster as detached from the background starfield, weakly concentrated toward the centre, moderate range in brightness, star-poor.

Sulentic & Tifft (1973)

(Sulentic and Tifft 1973) notes that this is a 8.5 mag open cluster.

Becker, W. (1963)

Becker, W. (1963) Die raumliche Verteilung von 156 galaktischen Sternhaufen in Abhangigkeit von ihrem Alter. Z. Astrophys., 57, 117. [comment on non-existent clusters]

"Bemerkungen: Die Objekte NGC 1807, NGC 7686, Tr.84 fehlen im Katalog, da sie keine realen Sternhaufen sind."

Becker & Fenkart (1971)

Becker, W. & Fenkart, R. (1971) A catalogue of galactic star clusters observed in three colours. Astr. Astrophys. Suppl., 4, 241.

p. 252: "Remarks". Included in their list of "not-physical Cluster"

Modern observations

Steve Gottlieb

05 10.8 +16 31

17.5: bright, moderately large, striking group of 30 stars mag 9-14 in 12' including 10 stars mag 11 or brighter. Five bright stars are in a 11' string oriented N-S. The central star in this string is a pleasing, close double star mag 10/11 at 10". This double is collinear with two mag 11 stars 1.3' E and 2.9' E oriented perpendicular to the string. Several other members trail to SW forming a cross asterism.

8: ~25 stars in cluster including 10-12 brighter stars, several almost collinear, double star 10/11 at 10" near center. Forms a pair with N1817 25' NE.

Walter Scott Houston

Houston calls it "one of an interesting pair of bright clusters in the same field of view", the other object being NGC 1817. He notes that the cluster contains about a score of stars of the 8th mag and fainter, as seen in a 4-inch refractor.

Raasch, Rick (1993)

writes in "The Focal Point", Volume 6, No. 3 (1993) "NGC 1807/1817 These two open clusters fit in the same field of view in a low power eyepiece, offering a very pleasing deep sky double. 1807 is about 8' in diameter with about 20 stars in a box or X-shape. 1817 is slightly larger, about 10' in diameter, and composed of about 75 relatively faint stars in a compact grouping reminiscent of NGC 7789 in Cassiopeia. This is a fine sight."

Ware, Donald J

NGC 1807/1817:"These two open clusters fit in the same field of view in a low power eyepiece, offering a very pleasing deep sky double. 1807 is about 8' in diameter with about 20 stars in a box or X-shape. 1817 is slightly larger, about 10' in diameter, and composed of about 75 relatively faint stars in a compact grouping reminiscent of NGC 7789 in Cassiopeia."

Contemporary observations

Auke Slotegraaf

2012 February 18, Saturday

Location: Paardeberg (ASSA Cape Centre dark sky site)[33:34.4S, 18:51.3E]

Time: 23:00 SAST.

SQM-L: 20.84 (22dC)

Binocs: 15x70 Celestron

NGC 1807 and NGC 1817 - Intruiging! Binoculars show two arcs of 9th mag stars, each 10' long, separated by twice that distance. The arcs are arranged biconvex, and lie more or less along the north-south axis. Between them is a lone faint star (HD 33480, 9.7V).

The easternmost arc, in NGC 1817, is made up of four stars (V=8.6 .. 9.7). Its brightest star (HD 33572, 8.6V) is at the northern tip of the arc. From here, a narrow (30 degrees) fan of very, very faint - actually, unseen - stars spreads out to the south and east, for perhaps 12'.

The westernmost arc, of four stars, has its brightest star (HD 33428, 8.6V) at the southern tip. It is contained in NGC 1807. The remainder of this grouping's stars are just hinted at.

NGC 1817 is far more prominent than NGC 1807.

These two clusters, together, remind me strongly of NGC 5128 (Centaurus A, the Hamburger Galaxy). They present two unequal, elongated, patches of light, with a dark gap between them, in which lies an isolated little star: the Hamburger Galaxy!

To find the pair of clusters, draw a line from Aldebaran (alpha Tau) to El Nath (beta Tau). Midway is iota Tau (4.6V). Sweep orthagonally to the south, slightly more than one binocular field (almost 5.5 degrees), for the duo. They are quite noticeable when sweeping through the region.

1981

8x40 binoculars show 2 or 3 prominent stars giving the cluster a curved appearance.

Magda Streicher

31 Jan 2008

NGC: 1807 - Taurus

Open Cluster

RA: 05h10m43.0 - DEC: +16o31'18"

Magnitude: 7 – Size: 17'

Tel: 12" S/C – 218x – Date: 31 Jan 2008 – Site: Alldays - good

This cluster contain brighter stars than the neighbor NGC 1817 which is 23' towards the NE. A big handful of stars in a very string formation NS but lovely and outstanding against the background. Contain a lot of yellow to orange stars in the grouping.

Tom Bryant

2008-02-02 21:00:00

Observing site: Little Tycho Observatory

Telescope: C-8

[5h 10m 42s, 16° 32m 0s] A large, (~ 40 arc minute), loose cluster of 10 or so bright stars. At the center is a double, 5", position angle 270, 8 - 9 mv. WDS identifies it as HJ 3268, 10", position angle 268, 9.4 - 10.1.