Trapezium


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trapezium

1. Chiefly Brit a quadrilateral having two parallel sides of unequal length
2. Now chiefly US and Canadian a quadrilateral having neither pair of sides parallel
3. a small bone of the wrist near the base of the thumb

Trapezium

(tră-pee -zee-ŭm) A very young open cluster of stars, protostars, gas, and dust that lies in the Orion nebula and is part of the Orion association. There are four prominent young main-sequence stars, which form the multiple star θ1 Orionis and are of spectral class O6, B1, B1, and B3. These stars excite and ionize the nebula. They form a trapezium and are visible with a small telescope.

Trapezium

 

the multiple star θ1 Orionis, located in the middle part of the Great Nebula of Orion. The star has nine known components, the four brightest of which (A, B, C, and D in Figure 1) form the vertices of a trapezium.

Figure 1. The Trapezium; the arrows at six of the stars indicate their proper motions over 1,000 years and the tangential velocity components on the scale indicated in the figure

In 1949, V. A. Ambartsumian discovered a number of similar stellar systems, in which the distances between components are of the same order of magnitude. Such systems came to be called Trapezium-type multiple stars. The periodic orbital motions observed in ordinary multiple stars are unlikely in Trapezium systems; consequently, such systems should be regarded as unstable and in the process of breaking up. According to Ambartsumian’s determinations, Trapezium systems break up in a few million years. It follows that such systems observed at the present time cannot be older than a few million years and are therefore young formations. A considerable number of Trapezium-type multiple stars are found in stellar associations.

trapezium

[trə′pē·zē·əm]
(mathematics)
A quadrilateral where no sides are parallel.

Trapezium

[trə′pē·zē·əm]
(astronomy)
Four very hot stars that appear to the eye as a single star in the Great Nebula of Orion; the star symbol is M42.
References in periodicals archive ?
An inclusive definition for a trapezium is a shape with one pair of parallel sides.
The mixtures were then degassed in vacuum desiccators for 1 hour to remove the entrapped air, followed by pouring into trapezium shape release-coated silicone mould before cured at room temperature for 24 hours.
There's an amazing choice from the easy-to-fly butterfly or bat kites to the more ambitious box or trapezium kites.
My notes indicate the "The Crux Galaxy" for this one guarded by a trapezium of stars closely surrounding the galaxy with a memorable impression of the Crux constellation.
Probably the most photographed object in the Northern sky, spectacular in large telescopes, small telescopes will show detail in the Nebula and the Trapezium stars in the centre that illuminate it from within.
Radial elements, including the radius, thumb, scaphoid, and trapezium, are absent.
Due to the failure to respond to treatment, subsequent investigations included a technetium bone scan, which showed increased uptake in the region of the trapezium, trapezoid and first and second metatarsal.
The importance of this discovery is two-fold: first, the cluster identified as a separate entity is only a slightly older sibling of the Trapezium cluster at the heart of the Orion nebula, and second, what astronomers have been calling the Orion Nebula Cluster (ONC) is actually a complicated mix of these two clusters.
3] loose lower canine tibia and lower premolar Right adult fibula in four fragments Right adult clavicle in two fragments Two possible pelvis fragments Fifteen fragments of vertebrae (cervical and thoracic) Eight rib fragments Hand bones: left adult metacarpal 4 two distal halves of adult proximal phalanges three complete adult middle phalanges three complete adult distal phalanges complete adult right capitate complete adult right trapezium Foot bones: complete adult left calcaneus three complete (or nearly complete) adult left metatarsals complete adult left second cuneiform possible phalanx base
Optimum dimensions of trapezium cross-section in structures, Facta Universitatis: Mechanical Engineering 1(5): 555-564.
India's Supreme Court in 1996 declared a 10,400-square-kilometer area a protected zone for the Taj Trapezium Zone after industries were found to be contributing to the monument's yellowing.