Lyre (constellation)
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Lyre constellation |
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| Latin name | Lyre |
| Latin genitive | Lyrae |
| Abbreviation | Lyric |
| Right ascension | 18 h 13 m 52 s to 19 h 28 m 29 s |
| declination | + 25 ° 39 ′ 51 ″ to + 47 ° 42 ′ 52 ″ |
| surface | 286,476 deg² rank 52 |
| Completely visible | 90 ° N to 42.6 ° S |
| Observation time for Central Europe | summer |
| Number of stars brighter than 3 mag | 1 |
| Brightest star (size) | Vega (0.03) |
| Meteor streams | |
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Neighboring constellations ( clockwise from north ) |
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| swell | IAU , |
 The constellation Lyra as it rises in the east on May and June evenings. |
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The lyre , technically lyre (from ancient Greek λύρα lýra , the musical instrument of the same name ), is a constellation of the northern sky, the brightest star of which is Vega .
Although it only covers an area of 6 × 10 °, it is one of the most striking summer constellations with the swan and eagle . In Central Europe, however, it can be seen in the evening from May to January.
description
The lyre is a small constellation that is easy to find in the evening summer and autumn sky and only dips towards the end of the year in the northwest.
The main star, Vega , is (with Arcturus ) the brightest star in the northern hemisphere and the fifth brightest star in the night sky. To the south of it, four stars form a parallelogram . They are supposed to represent the strings of an ancient lyre.
The famous ring nebula M57 lies exactly between the stars β and γ Lyrae .
The Wega forms the great summer triangle with the stars Deneb (constellation Swan ) and Altair (constellation eagle ) .
The Milky Way runs south of the lyre . If you examine the surrounding area through binoculars , many faint stars and various bright and dark galactic clouds become visible.
history
The lyre is one of the 48 constellations of antiquity , which were already described by Ptolemy . On older star maps, instead of the lyre, a bird is often depicted, usually a vulture. This and the constellations swan and eagle are supposed to represent the stymphalic birds , monsters from Greek mythology with iron beaks.
The Arab astronomers of the Middle Ages saw in the constellation a "descending eagle" (al-nasr al-waqi).
Vega was the first star to be photographed (1850).
mythology
The lyre represents the musical instrument invented by the Greek god Hermes . He gave it to his half-brother Apollon , who in turn gave it to the famous singer Orpheus . The latter beguiled their god Hades in the underworld in order to save his bride Eurydice, who had died of a snakebite . When leaving the underworld, however, he violated the command not to look back; then Eurydice had to stay in the underworld. After Orpheus' death the lyre was moved to the starry sky.
The stymphalic birds come from the legends surrounding the Greek hero Herakles . His sixth task was to kill the birds.
Meteor streams
In the lyre lies the radian of the meteor shower of the Lyrids . Its maximum is between April 20th and April 22nd of each year.
Celestial objects
Stars
| B. | F. | Names or other designations | size | Lj | Spectral class |
|---|---|---|---|---|---|
| α | 3 | Wega (Vega) | 0.03 m (var) | 25.0 | A0 Va |
| γ | 14th | Sulafat | 3.25 m | 550 | B9 III |
| β | 10 | Sheliak | 3.42 m (var) | 1,000 | B6-8 II + B0.5 V + B7 V + G5 |
| 13 | R. | 4.00 m (var) | 310 | M5 III | |
| δ 2 | 12 | 4.30 m (var) | 700 | M4 II | |
| κ | 1 | 4.34 m | 255 | K2 IIIabCN0.5 | |
| ζ 1 | 6th | 4.36 m | 158 | A4m | |
| θ | 21st | 4.38 m | 700 | K0 II | |
| η | 20th | Aladfar | 4.40 m | 900 | B2.5 IV |
| ε 2 | 5 | 4.59 m | 162 | A6 Vn + A7 Vn | |
| ε 1 | 4th | 4.66 m | 160 | A3 V + F0 V | |
| HR 7064 | 4.84 m | 240 | K2 III | ||
| λ | 15th | 4.93 m | 1,300 | K2.5 III: Ba0.5 | |
| 16 | 5.01 m | 126 | A6 IV | ||
| μ | 2 | 5.12 m | 410 | A0 IV | |
| 17th | 5.22 m | 143 | F0 V | ||
| ν 2 | 9 | 5.23 m | 230 | A3 V | |
| ι | 18th | 5.25 m (var) | 900 | B6 IV | |
| HR 7162 | 5.25 m | 49 | F9 V + K1 V | ||
| HR 7181 | 5.26 m | 330 | K2 III | ||
| HR 6997 | 5.41 m | 530 | B8 IIpHgMn | ||
| HR 7146 | 5.44 m | 266 | G8 III | ||
| HR 6968 | 5.47 m | 350 | B8 IV | ||
| HR 7253 | 5.55 m | 134 | F0 III | ||
| HR 6845 | 5.56 m | 590 | B7 IV | ||
| HR 7237 | 5.56 m | 550 | M0 III | ||
| δ 1 | 11 | 5.57 m | 1,200 | B2 V | |
| ζ 2 | 7th | 5.59 m | 158 | F0 IVvar | |
| HR 7132 | 5.62 m | 420 | K4 III | ||
| HR 7044 | 5.68 m | 165 | F1 III-IV | ||
| HR 7202 | 5.69 m | 790 | B5 V | ||
| HR 7140 | 5.79 m | 1,200 | G5 III + A8 | ||
| HR 7302 | 5.85 m | 910 | M0 III | ||
| HR 7382 | 5.85 m | 435 | G7 IIIa | ||
| V542 | 5.88 m (var) | 690 | B7 IV | ||
| ν 1 | 8th | 5.91 m | 1,180 | B3 IV | |
| 19th | V471 | 5.93 m (var) | 940 | B8 IIIpSiSr | |
| XY | 6.05 m (var) | 1,500 | M4.5-5 II | ||
| HD 178911 | 6.74 m | 161 | G1 V + K1 V | ||
| RR | 7.06 m (var) | 900 | A8-F7 | ||
| HD 177830 | 7.18 m | 205 | K0 + M4 V | ||
| Kepler 444 | 8.86 m | 119 | K0 V | ||
| Kepler 37 | 9.77 m | 209 | G or K | ||
| WASP-3 | 10.63 m | 760 | F7 V | ||
| GJ 747 (17 Lyrae C) | 11.26 m | 27.1 | M3 + M5 | ||
| GSC 02652-01324 (V672) | 11.42 m (var) | 520 | K0 V | ||
| HAT-P-5 | 11.95 m | 1,000 | G1 V | ||
| Kepler 102 | 12.07 m | 353 | |||
| Kepler-20 | 12.51 m | 930 | G8 | ||
| Kepler-7 | 12.9 m | 3,100 | G0 | ||
| Kepler-138 | 13.4 m | 219 | M1 V | ||
| Kepler-62 | 13.8 m | 990 | K2 V | ||
| Kepler-438 | 14.9 m | 640 | M1 V | ||
| Kepler 442 | approx. 15 m | 1,210 | |||
| MR | 15.4 m (var) | 18,000 | |||
| Kepler-30 | 15.5 m | 3,100 | G9-K0 | ||
| Kepler-46 | approx. 15.5 m | 2,600 | |||
| LSR J1835 + 3259 | 18.3 m | 18.6 | M8.5V |
Wega (α Lyrae) is the main star of the lyre and is strikingly bright with an apparent magnitude of 0.03 m - it is the fifth brightest star in the night sky (after Sirius , Canopus , Arcturus and α Centauri ). The star has 40 times the luminosity of the sun and emits a whitish light ( spectral type A0). At a distance of 25 light years , it is one of the closest brighter stars around the sun. Wega rotates on its own axis in just 17 hours, which has deformed it into an ellipsoid of revolution and shows a non-uniform surface temperature : It is 7,600 K at the equator and 10,000 K at the poles. The name Vega is derived from the Old Arabic and means "the falling eagle".
Sheliak (β Lyrae) is a multiple star system and eclipsing star ( see sections Binary Stars and Variable Stars ). The Arabic name Sheliak means "turtle".
Part of the constellation was in the coverage area of the Kepler space telescope , which systematically searched for exoplanets using the transit method . For the stars Kepler-62 , Kepler-438 and Kepler-442 planets were discovered that are probably in the habitable zone .
An LSR J1835 + 3259 succeeded in 2015 for the first time the detection of aurorae on a celestial body outside the solar system. The exact classification of LSR J1835 + 3259 has not been fully clarified: some authors assume an ultra-cool red dwarf star , others a brown dwarf .
Double stars
| system | Sizes | distance |
|---|---|---|
| β | 3.4 m / 7.1 m / 13 m / 14.3 m / 10.1 m / 10.6 m | 45.7 ″ / 46.4 ″ / 64.4 ″ / 67.1 ″ / 85.7 ″ |
| γ | 3.3 m / 12.1 m | 13.5 ″ |
| δ | 4.3 m / 5.6 m | 619 ″ |
| ε | 5.0 m / 6.1 m / 5.1 m / 5.4 m | 209.5 ″ / 2.3 ″ / 2.3 ″ |
| ζ | 4.4 m / 5.6 m | 43.8 ″ |
| ι | 5.3 m / 6.1 m | 0.2 ″ |
| 17th | 5.3 m / 9.1 m / 11.9 m / 12.2 m | 291.9 ″ / 3.2 ″ / 0.3 ″ |
The star Sheliak (β Lyrae), about 1,000 light years away - itself a spectroscopic binary star with a period of 12.91 days - is surrounded by several faint stars, namely (magnitude and distance in brackets) β Lyrae B (7.1 m , 45.7 ″), C (13 m , 46.4 ″), D (14.3 m , 64.4 ″), E (10.1 m , 67.1 ″) and F (10.6 m , 85.7 ″). Of this, only the components B and F seem to belong spatially to Sheliak, all other stars are background stars.
One of the most famous multiple stars in the night sky is the "double double star" ε Lyrae . This consists of the stars ε 1 and ε 2 Lyrae, which are just 3.5 arc minutes apart and can be seen elongated or even separately by observers with good visual acuity with the naked eye ( see also: Eye tester ). Both components are now double again, each 2.3 ″ apart. A telescope with at least 6 cm aperture shows all four stars. The periods of rotation are around 1,800 years for the ε 1 system (5.0 m and 6.1 m ) and around 720 years for the ε 2 system (5.1 m and 5.3 m ). In turn, the two systems orbit each other once every approximately 340,000 years. The ε-Lyrae system is 160 light years away from us.
17 Lyrae has a physical companion in ninth size class (17 Lyrae B) at a 3.2 ″ distance. Since 17 Lyrae is also a spectroscopic double star, it is therefore a triple system. About 292 ″ away from this is 17 Lyrae C (GJ 747), with a distance of 27 light years a foreground star , which with 17 Lyrae consequently only forms an optical double star . GJ 747 itself is also a physical double star, consisting of two red dwarfs , which have an angular distance of only 0.3 "and a mutual orbital period of 5.78 years.
Spectroscopic binary stars in the lyre are (in brackets the period): Sheliak (12.91 days), δ 1 Lyrae (88.35 days), ζ 1 Lyrae (4.3 days), η Lyrae (56.4 days) and 17 lyre (42.88 days).
Variable stars
| star | size | period | Type |
|---|---|---|---|
| α | −0.02 m to 0.07 m | 0.19 days | δ Scuti star |
| β | 3.3 m to 4.4 m | 12.91 days | β-Lyrae star |
| δ 2 | 4.2 m to 4.3 m | semi-regularly changeable | |
| 19th | 5.9 m to 6.0 m | 1.16 days | α 2 -Canum Venaticorum star |
| R. | 3.9 m to 5.0 m | 46 days | semi-regularly changeable |
| RR | 7.1 m to 8.1 m | 0.57 days | RR Lyrae star |
| XY | 5.8 m to 6.4 m | irregularly variable (Lc) |
Wega (α Lyrae) has long been used as the standard photometric star . In the Johnson-Morgan system , their apparent brightness and their color indices (U − B and B − V) were defined as 0. However, exact measurements show that Vega is a weakly variable star. It is assigned to the δ-Scuti stars ; its light curve fluctuates with a period of four and a half hours in the order of magnitude of a tenth of a magnitude.
The main star of the Sheliak system (β Lyrae) is the namesake of a type of eclipsing star , the β Lyrae stars . They are double stars that orbit each other at a close distance, whereby one of the stars has reached its final stage and has expanded into a giant star . The gas from the shell of the giant star overflows onto the main star. With each orbit of the stars (here: 12.91 days) it comes to a partial occultation, whereby the brightness decreases periodically. The maximum brightness of Sheliak is 3.3 m and drops to 3.9 m at the minor minimum (the giant covers the main star) and to 4.4 m at the main minimum (the main star covers the giant).
The lyre is also home to another prototype of variable stars, namely RR Lyrae . RR Lyrae is the namesake for a class of variable pulsation stars , the RR Lyrae stars .
Messier and NGC objects
| Messier (M) | NGC | other | size | Type | Surname |
|---|---|---|---|---|---|
| 56 | 6779 | 8.4 m | Globular clusters | ||
| 57 | 6720 | 8.8 m | planetary nebula | Ring nebula | |
| 6703 | 11.3 m | lenticular galaxy | |||
| 6743 | open star cluster | ||||
| 6765 | 12.9 m | planetary nebula | |||
| 6791 | 9.5 m | open star cluster | |||
| IC 1296 | 14.0 m | Spiral galaxy | |||
| Stephenson 1 | 3.8 m | open star cluster | δ-Lyrae cluster | ||
| Kronberger 61 | planetary nebula |
In the lyre there are two objects that the French astronomer and comet hunter Charles Messier included in his catalog of foggy objects ( Messier catalog ).
M 56 is a globular cluster about 30,000 light years away. In binoculars it can be seen as a misty spot. In order to resolve it into single stars at the edge, however, you need a telescope with an opening of at least 15 cm.
About in the middle of the imaginary connecting line β - γ Lyrae is M 57 , the famous ring nebula in the lyre. It is the remnant of a star that, at the end of its evolution, shed its outer gas envelope. Because such remnants of stars appeared to earlier astronomers in their instruments like planetary disks, they are called planetary nebulae . To observe the Ring Nebula (as a flat object) you need a telescope or telescope with a 7 cm opening. From an opening of 10 to 12 cm, its ring-hole shape can also be recognized, which is reminiscent of an oval smoke ring .
Very close to the Ring Nebula (approx. 4 arc minutes away) is a faint background galaxy, namely IC 1296. Visually, it is only visible with large telescopes with an opening of 40 cm or more.
Around δ Lyrae there is the δ-Lyrae cluster (Stephenson 1), an open star cluster . The loose cluster of only a few stars can be seen with binoculars and is around 1,200 light years away. While δ 1 Lyrae is a physical cluster member, δ 2 Lyrae is only a foreground star, 700 light years away.
