Philips Atlas of the Universe

Auriga, Lynx

A

uriga, the Charioteer, is a brilliant northern constella-

tion, led by Capella. In mythology it honours

Erechthonius, son of Vulcan, the blacksmith of the gods;

he became King of Athens, and invented the four-horse

chariot.

Capella is the sixth brightest star in the entire sky, and

is only 0.05 of a magnitude inferior to Vega. It and Vega

are on opposite sides of the north celestial pole, so that

when Capella is high up Vega is low down, and vice

versa; from Britain, neither actually sets, and Capella is

near the zenith or overhead point during evenings in

winter. It can be seen from almost all inhabited countries,

though it is lost from the extreme southern tip of New

Zealand.

Capella is yellow, like the Sun, but is a yellow giant

rather than a dwarf – or, rather, two giants, because it is a

very close binary. One component is 90 times as luminous

as the Sun, and the other 70 times; the distance between

them is not much more than 100 million kilometres (60

million miles).

The distance from us is 42 light-years. The second star

of Auriga, ‚(Menkarlina), is also a spectroscopic binary,

and is actually an eclipsing system with a very small

magnitude range. The components are more or less equal,

and a mere 12 million kilometres (7.5 million miles) apart;

both are of type A.

Of course, the most intriguing objects in Auriga are

the two eclipsing binaries Âand ̇, which have been

described earlier. It is sheer chance that they lie side by

side, because they are at very different distances – 520

light-years for ̇; as much as 4600 light-years for Â. The

third member of the trio of the Haedi or Kids, ËAurigae,

is a useful comparison; the magnitude is 3.17.

It is worth keeping a close watch on Â, because even

during long intervals between eclipses it seems to fluctuate

slightly. The catalogues give its normal magnitude as 2.99,

in which case it appears very slightly but perceptibly

brighter than Ë. All three Kids are in the same low-power

binocular field, and this is probably the best way to make

estimates of Â; ̇is much fainter, and the only really useful

comparison star is Ó, of magnitude 3.97.

Of the other main stars of the Charioteer, Èand the

rather isolated ‰,are reddish, with K-type spectra. ıis

white, and has two companions; the closer pair makes up

a slow binary system, while the more remote member of

the group, of magnitude 10.6, merely lies in almost the

same line of sight.

Auriga is crossed by the Milky Way, and there are

several fine open clusters, of which three are in Messier’s

list. M36 and M38 were both discovered by Guillaume

Legentil in 1749, and M37 by Messier himself in 1764;

but no doubt all had been recorded earlier, because all are

bright.

M36 is easy to resolve, and is 3700 light-years away.

M37, at about the same distance, is in the same lower-

power field as ı, which is a very good way of identifying

it; the brightest stars in the cluster form a rough trapezium.

M38 is larger and looser, and rather less bright. It lies

slightly away from the mid-point of a line joining ıto

È, and within half a degree of it is a much smaller and

dimmer cluster, NGC1907.

Note also the Flaming Star Nebula round the irregular

variable AE Aurigae – one of the ‘runaway stars’ which

seem to have been ejected from the Orion nebulosity

(the others are 53 Arietis and ÌColumbae). AE Aurigae

illuminates the diffuse nebulosity, which is elusive tele-

scopically though photographs show intricate structure.

The distance is of the order of 1600 light-years.

Lynxis a very ill-defined and obscure northern constella-

tion, created by Hevelius in 1790; it has no mythological

associations, and it has been said that only a lynx-eyed

observer can see anything there at all. In fact there is

one brightish star, ·(magnitude 3.13), which is decidedly

isolated, and forms an equilateral triangle with Regulus

ATLAS OF THE UNIVERSE

Capella, the brightest

star in Auriga – and the

sixth brightest star in the

entire sky – is near the zenith

or overhead point during

evenings in winter, as

seen from the northern

hemisphere; this is the

position occupied by Vega

during summer evenings.

From Britain or the northern

United States, Capella does

not set, though at its lowest

it skims the horizon. The

Auriga quadrilateral is very

easy to identify; a fifth bright

star, Alnath, which seems

logically to belong to the

Auriga pattern, has been

transferred to Taurus, and

is now ‚Tauri instead of

ÁAurigae.

Magnitudes

Variable star

Galaxy

Planetary nebula

Gaseous nebula

Globular cluster

Open cluster

–1

0 1 2 3 4 5

URSA MAJOR

CAMELOPARDALIS

LYNX

AURIGA

CANCER

LEO MINOR

GEMINI TAURUS

Capella

Castor

Pollux

M38

M36

M37

‰

‚

·

Â

Ë ̇

Ó

ı

È

‚

̇

·

38

31

15

58

UU

2683

2419 1857

IC405

PERSEUS

Ô

ı

Î

È

̇

Ì

Â

Á

È

·

‚

Î

‰

̇

Ù

ı

Â

Ì

Ë

1907

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