Custos Messium

This constellation was invented in Early Modern Time by the French astronomer Joseph Jérôme de Lalande (1732–1807). Custos Messium is recognized as an 'extinct constellation' that fell into obscurity after the early 19th century.

Concordance, Etymology, History

Origin of Constellation

Custos Messium as Vineyard Keeper in Young (1807). A Course of Lectures on Natural Philosophy and the Mechanical Arts.

Ian Ridpath writes:

This far-northern constellation was introduced by the French astronomer Joseph Jérôme de Lalande (1732–1807) on his celestial globe of 1775, and was described by him in an accompanying pamphlet titled Explication des nouveaux globes céleste et terrestre (see this review from the Journal des Sçavans of 1776 November). The name Custos Messium is a punning reference to his countryman Charles Messier, the famed comet hunter, and in fact the constellation was often known simply as Messier, particularly in France. Its brightest star was the present-day 50 Cassiopeiae, of 4th magnitude.

(...)

Lalande chose this previously anonymous area of sky because it was here that the comet of 1774 (now known as C/1774 P1) was first seen. The comet was extensively observed by Messier but, ironically, was not discovered by him – the discoverer in this case was actually another Frenchman, Jacques Laibats-Montaigne (1716–88).

The British scientist Thomas Young (1773–1829) renamed the figure the Vineyard Keeper on his chart of the northern hemisphere sky published in 1807 in A Course of Lectures on Natural Philosophy and the Mechanical Arts, but even this was not enough to broaden its appeal and it withered into obscurity.

John Barentine (2016), has a chapter on Custos Messium in Chapter 7, Figure 8.10 of his book shows Custos Messium outlined in a modern star map.

Stars inside the Constellation Area (Eric, manually)

Custos Messium and Rangifer Constellation Position on a modern map (CC BY Ultima Thulean, SA)

Some of the naked eye stars within the region of sky covered by Custos Messium include (in order of apparent V magnitude):

label	HIP	HD	description	IAU-name	Vmag
50 Cas	HIP 9598	HD 12216			3.95
BE Cam	HIP 17884	HD 2347			4.39
48 Cas	HIP 9480	HD 12111			4.49
gam Cam	HIP 17959	HD 23401			4.59
BK Cam	HIP 15520	HD 20336			4.74
ome Cas	HIP 9009	HD 11529			4.97
42 Cas	HIP 8016	HD 10250			5.18
49 Cas	HIP 9763	HD 12339			5.22
47 Cas	HIP 9727	HD 12230			5.27
40 Cas	HIP 7650	HD 9774			5.28
23 Cas	HIP 3721	HD 4382			5.42
21 Cas	HIP 3572	HD 4161			5.64
38 Cas	HIP 7078	HD 9021			5.82
SU Cas	HIP 13367	HD 17463			5.94
RZ Cas	HIP 13133	HD 17138			6.26
54 Cas	HIP 10031	HD 12800			6.57

The only star brighter than 4th magnitude in Custos Messium is 50 Cas (HIP 9598, HD 12216) a V=3.95 magnitude A2V main sequence star at distance 48 parsecs.

Stars within the Constellation Area

Custos Messium stickfigure in Sky Culture Maker (Dec. 2025), CC BY Youla Azkarrula.

This table is an output by our newly developed "Sky Culture Maker" tool. It automatically computes the convex hull of a stick figure and then extracts all stars from the Naked Eye (star) Catalog (NEC) that are inside these boundaries. The routine of extraction works; but the display of the hull on the map is still buggy.

id	Label	IAU design.	description	Vmag
1	50 Cas	HIP 9598	Constellation lines	3.938
2	BE Cam	HIP 17884	Constellation lines	4.48
3	48 Cas	HIP 9480	Constellation lines	4.54
4	γ Camelopardalis	HIP 17959	Constellation lines (Vertex)	4.604
5	* iot Cas A	HIP 11569	Inside the hull	4.61
6	* 48 Cas A	HIP 9480	Constellation lines	4.63
7	ψ Cassiopeiae	HIP 6692	Constellation lines	4.727
8	-	HIP 17587	Constellation lines	4.81
9	-	HIP 14862	Constellation lines (Vertex)	4.834
10	BK Cam	HIP 15520	Inside the hull	4.85
11	ω Cassiopeiae	HIP 9009	Inside the hull	4.968
12	-	HIP 18505	Constellation lines (Vertex)	5.04
13	BD Cam	HIP 17296	Inside the hull	5.11
14	-	HIP 12273	Constellation lines	5.166
15	42 Cas	HIP 8016	Inside the hull	5.174
16	CQ Cam	HIP 15890	Inside the hull	5.19
17	49 Cas	HIP 9763	Constellation lines	5.22
18	47 Cas	HIP 9727	Inside the hull	5.268
19	-	HIP 9312	Inside the hull	5.278
20	40 Cas	HIP 7650	Constellation lines	5.281
21	31 Cas	HIP 5518	Inside the hull	5.309
22	-	HIP 17854	Inside the hull	5.391
23	23 Cas	HIP 3721	Inside the hull	5.413
24	-	HIP 13665	Constellation lines	5.584
25	43 Cas	HIP 7965	Inside the hull	5.59
26	53 Cas	HIP 9573	Inside the hull	5.614
27	YZ Cas	HIP 3572	Constellation lines	5.652
28	Cl Collinder 463	Cl Collinder 463	Inside the hull	5.7
29	-	HIP 12239	Inside the hull	5.781
30	-	HIP 17585	Constellation lines	5.782
31	-	HIP 7078	Inside the hull	5.8
32	SU Cas	HIP 13367	Inside the hull	5.8
33	-	HIP 17891	Inside the hull	5.817
34	-	HIP 3750	Inside the hull	5.855
35	V762 Cas	HIP 5926	Inside the hull	5.86
36	-	HIP 14502	Inside the hull	5.877
37	-	HIP 12821	Inside the hull	5.945
38	-	HIP 116714	Constellation lines (Vertex)	5.946
39	-	HIP 116728	Constellation lines (Vertex)	5.973
40	52 Cas	HIP 9564	Inside the hull	5.986
41	-	HIP 9568	Constellation lines (Vertex)	6.046
42	-	HIP 6522	Constellation lines	6.064
43	55 Cas	HIP 10438	Inside the hull	6.07
44	-	HIP 7050	Inside the hull	6.137
45	-	HIP 9586	Inside the hull	6.15
46	-	HIP 13700	Inside the hull	6.167
47	-	HIP 2422	Inside the hull	6.19
48	RZ Cas	HIP 13133	Inside the hull	6.26
49	-	HIP 10350	Constellation lines	6.261
50	-	HIP 18067	Inside the hull	6.299
51	-	HIP 6261	Inside the hull	6.318
52	-	HIP 6685	Inside the hull	6.36
53	-	HIP 117712	Constellation lines	6.38
54	-	HIP 3641	Constellation lines	6.38
55	-	HIP 2628	Inside the hull	6.38
56	-	HIP 6378	Inside the hull	6.38
57	-	HIP 4446	Constellation lines	6.386
58	-	HIP 4709	Inside the hull	6.4
59	-	HIP 13487	Inside the hull	6.408
60	V805 Cas	HIP 16319	Inside the hull	6.41
61	-	HIP 128	Inside the hull	6.492
62	V801 Cas	HIP 14626	Inside the hull	6.498
63	-	HIP 14791	Inside the hull	6.5
64	-	HIP 7339	Inside the hull	6.51
65	-	HIP 13004	Constellation lines (Vertex)	6.525
66	-	HIP 5531	Inside the hull	6.55
67	-	HIP 10031	Constellation lines	6.57
68	-	HIP 9147	Inside the hull	6.61
69	-	HIP 14286	Inside the hull	6.64
70	-	HIP 6099	Constellation lines	6.68
71	-	HIP 3145	Constellation lines	6.73
72	-	HIP 6379	Inside the hull	7.167
73	-	HIP 6385	Constellation lines (Vertex)	7.21
74	-	HIP 6175	Inside the hull	7.27
75	V393 Cas	HIP 522298298421891456	Constellation lines	7.42
76	-	HIP 8057	Inside the hull	7.58

Transfer and Transformation of the Constellation

• 

  Custos Messium in Bode (1782)

• 

  Custos Messium in Bode (1801)

• 

  Custos Messium as Vineyard Keeper in Young (1807): A Course of Lectures on Natural Philosophy and the Mechanical Arts.

• 

  Sidney Hall’s (1831)

• 

  Custos Messium and Rangifer Constellation Position on a modern map (CC BY Ultima Thulean, SA)

Mythology

no mythology.

IAU Working Group on Star Names

The name "Custos" (Latin for "guard") has been proposed as a proper name for a star in the vicinity of Custos Messium to be discussed by WGSN.

References

• References (general)
• References (ancient Greco-Roman)
• References (medieval)