Fox (constellation)
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Constellation fox |
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| Latin name | Vulpecula |
| Latin genitive | Vulpeculae |
| Abbreviation | Vul |
| Right ascension | 18 h 57 m 07 s to 21 h 30 m 39 s |
| declination | + 19 ° 23 ′ 54 ″ to + 29 ° 29 ′ 14 ″ |
| surface | 268,165 deg² rank 55 |
| Completely visible | 90 ° N to 60.7 ° S |
| Observation time for Central Europe | July September |
| Number of stars brighter than 3 mag | 0 |
| Brightest star (size) | Anser (4.44) |
| Meteor streams |
no |
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Neighboring constellations ( clockwise from north ) |
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| swell | IAU , |
The fox ( Latin Vulpecula , literally little fox or fox ) is a constellation in the northern sky.
description
The fox is a constellation between the distinctive swan (Cygnus) and the arrow (Sagitta). None of its stars are brighter than the 4th magnitude .
The star-rich ribbon of the Milky Way runs through the fox, which is why it contains a number of open star clusters . Interesting objects to observe are the planetary nebula M 27, also called the dumbbell nebula , and the conspicuous star constellation Collinder 399 .
history
The constellation was introduced at the end of the 17th century by the Danzig astronomer Johannes Hevelius . Originally it was called Vulpecula cum ansere ( Eng . Fox with goose ). The goose that the fox held in its claws is no longer an official constellation, but the name of the brightest star Anser (also called Lukida Anseris ) reminds of the poultry. The fox immortalized in this constellation once terrorized ancient Thebes . Even Lailaps, the dog of Artemis , had not been able to bring him down, whereupon Zeus had promoted both the dog and the fox into the sky, but positioned them in opposite places.
In 1967 Antony Hewish and Jocelyn Bell from Cambridge University discovered the first pulsar ( PSR B1919 + 21 ) in the Fuchs . In August 2010, the Einstein @ home project identified another, previously undiscovered pulsar.
Celestial objects
Stars
Only the brightest star has with Alpha Vulpeculae
The main star of the fox is Alpha Vulpeculae , which also bears the traditional proper names Anser and Lukida Anseris. It is a red giant with 40 times the diameter and 400 times the luminosity of the sun and an effective surface temperature of 4000 K . The distance of the star is about 300 light years. He's the only one with a Bayer designation .
| F. | Names or other designations | Size (mag) | Lj | Spectral class |
|---|---|---|---|---|
| 6th | Anser (Lukida Anseris) | 4.45 | 300 | M0.5 III |
| 23 | 4.52 | 340 | K3 IIIFe | |
| 13 | 4.56 | 330 | B9.5 III | |
| 31 | 4.57 | 190 | G7 IIIFe | |
| 15th | NT | 4.65 (var) | 240 | A4 III |
| QR | 4.75 (var) | 1,000 | B3 V | |
| 1 | 4.77 | 800 | B4 IV | |
| 29 | 4.82 | 230 | A0 V | |
| 30th | 4.91 | 320 | K1 III | |
| 12 | V395 | 4.96 (var) | 630 | B2.5 Ve |
| 9 | 5.00 | 550 | B8 IIIn | |
| 32 | 5.01 | 600 | K4 III | |
| 28 | 5.05 | 520 | B5 IV | |
| 17th | 5.06 | 500 | B3 V | |
| 4th | 5.16 | 270 | K0 III | |
| 22nd | QS | 5.18 (var) | 2,000 | G5 Ib-II + B8 V |
| 3 | V377 | 5.19 (var) | 400 | B6 III |
| 21st | NU | 5.19 (var) | 300 | A7 IVn |
| 16 | 5.20 | 220 | F2 III | |
| 33 | 5.29 | 450 | K3.5 III | |
| 24 | 5.30 | 440 | G8 III | |
| 35 | 5.38 | 190 | A1 VmA3 | |
| 2 | IT | 5.39 (var) | 1,200 | B0.5 IV |
| 19th | 5.49 | 1,400 | K2 IIIaCa | |
| 10 | 5.50 | 330 | G8 III | |
| 18th | 5.51 | 420 | A2 IV | |
| HR 7601 | 5.52 | 470 | A0 III | |
| 25th | 5.56 | 1,000 | B6 IVe | |
| 34 | 5.57 | 270 | K1 III | |
| HR 7573 | 5.57 | 1,700 | A2 Ia | |
| 27 | 5.58 | 320 | B8 V | |
| 5 | 5.59 | 240 | A0 V | |
| 14th | 5.66 | 160 | F0 | |
| HR 8198 | 5.66 | 220 | A8 III | |
| HR 7811 | 5.67 | 480 | G6 III | |
| HR 8190 | 5.69 | 170 | F1 IV | |
| T | 5.77 (var) | 1,700 | F5 Ib + A 0.8V | |
| HR 7250 | 5.79 | 350 | A4 III | |
| 8th | 5.81 | 500 | K0 III | |
| HR 7656 | 5.81 | 1,100 | B4 V | |
| HR 7391 | 5.87 | 600 | M0 III | |
| HR 7421 | 5.89 | 200 | K0 III-IV | |
| 20th | 5.92 (var) | 800 | B7 Ve | |
| HR 7895 | 5.93 | 2,000 | K1 II + B7 | |
| HR 7540 | 6.00 | 410 | K0 II-III | |
| 7th | 6.33 | 1,200 | B4–5 III – IVe + B (?) | |
| 26th | 6.41 | 700 | A5 III | |
| HD 190228 | 7.30 | 210 | G5 IV | |
| HD 189733 (V452) | 7.64 (var) | 65 | K0 V + M4 V | |
| HD 188015 | 8.23 | 190 | G5 IV | |
| NQ (Nova Vulpeculae 1976) | 17.2 (var) | 4,000 | ||
| QU (Nova Vulpeculae 1984 # 2) | 17.9 (var) | 8,000 | ||
| 11 | CK (Nova Vulpeculae 1670) | 2,300 | ||
| PSR B1919 + 21 | 3,000 | |||
| PSR J2007 + 2722 | 17,000 |
Double stars
| system | Sizes (mag) | distance |
|---|---|---|
| 1 | 4.8 / 11.6 | 39.1 ″ |
| 2 | 5.4 / 8.7 / 10.4 | 1.8 ″ / 51.5 ″ |
| 13 | 4.6 / 7.4 | 1.4 ″ |
| 16 | 5.8 / 6.1 | 0.9 ″ |
| QR | 4.8 / 7.6 | 0.5 ″ |
| Dumbbell nebula (central star) |
14/17 | 6.4 ″ |
A close double star is 16 vulpeculae. With a distance of 0.9 ″, it is well suited as a test object for a medium-sized amateur telescope or telescope due to the almost identical brightness of the components. To resolve it into two single stars, you need a refractor with a 15 cm opening (a slightly larger opening is recommended for a reflector). To separate you should enlarge at least 300 times. 16 Vulpeculae is 220 light-years away and has an orbital period of 1,200 years.
The central star of the Dumbbell Nebula (M 27), a white dwarf , is a physical double star. At a distance of 6.4 ″ it has a 17 mag bright red dwarf as a companion.
Spectroscopic binary stars in the fox are (in brackets the period of rotation): 1 vulpeculae (249.4 days), 3 vulpeculae (367.76 days) 7 vulpeculae (69.3 days), 18 vulpeculae (9.316 days), 22 vulpeculae (249, 2 days), 26 vulpeculae (11.088 days), 30 vulpeculae (6.86 years) and 31 vulpeculae (5.09 years). In addition, 23 Vulpeculae is a close binary star with a period of 25.33 years, but this is not one of the spectroscopic binary stars.
Asterisms
α Vulpeculae is an optical double star that can be recognized as such even with free eyes - assuming good sky conditions. The star 8 Vulpeculae is visible at a distance of 428 ″. In fact, both stars are only in one direction when viewed from Earth. They are more than 200 light years apart and are not bound to each other by gravity.
Variable stars
| star | Size (mag) | period | Type |
|---|---|---|---|
| 2 | Amplitude = 0.06 | 0.61 days | Beta Cephei star |
| 3 | Amplitude = 0.03 | slowly pulsating B star | |
| 12 | 4.8 to 5.0 | Be star | |
| 15th | 4.6 to 4.7 | 14 days | Cor Caroli |
| 21st | Amplitude = 0.05 | 0.23 days | Delta Scuti star |
| 22nd | Amplitude = 0.12 | 249.2 days | ζ aurigae star |
| QR | 4.6 to 4.8 | Gamma Cassiopeiae star | |
| T | 5.4 to 6.1 | 4.44 days | Cepheids |
22 Vulpeculae (QS Vulpeculae) is an eclipsed star with a period of 249.2 days. It is classified as a ζ Aurigae star, a variable type of star that resembles the Algol stars . The main star is a four and a half solar masses heavy yellow supergiant of the spectral type G5, its companion a main sequence star with three solar masses of the spectral type B8.
Bright novae that lit up in the fox were CK Vulpeculae (1670 to 1672), NQ Vulpeculae (1976), and QU Vulpeculae (1984). The Nova CK Vulpeculae was discovered in June 1670, making it the first documented Nova. It lit up three times between 1670 and 1672 so that it was visible to the naked eye. It also received the Flamsteed designation 11 Vulpeculae. After that, the nova faded and was nowhere to be found for centuries. It was not rediscovered until 1981. A faint bipolar nebula was found with a compact radio source in the center . The exact nature of the Nova has not yet been adequately clarified. It is believed that it was not a classic nova, but a much rarer event ( bright red nova , diffusion-induced nova or later thermal pulse ).
Messier and NGC objects
| Messier (M) | NGC | other | Size (mag) | Type | Surname |
|---|---|---|---|---|---|
| 27 | 6853 | Dumbbell nebula | 7.4 | planetary nebula | |
| 6793 | 8.5 | open star cluster | |||
| 6802 | 8.8 | open star cluster | |||
| 6820 | Emission nebula | ||||
| 6823 | 8.8 | open star cluster | |||
| 6827 | 12 | open star cluster | |||
| 6830 | 7.9 | open star cluster | |||
| 6885 (= 6882) | 8.1 | open star cluster | |||
| 6940 | 8.8 | open star cluster | |||
| Collinder 399 | 3.6 | Asterism | Pile of hangers | ||
| Floor 1 | 5.3 | open star cluster | |||
| Hen 2-437 | 15th | planetary nebula |
M 27, the dumbbell nebula , is one of the most famous planetary nebulae . It was discovered by Charles Messier in 1764 as the first object of its kind. It is the ejected gas envelope of a star. The nebula can already be observed with binoculars as a weakly shining disc with a diameter of about 6 ′. Lighter structures that are reminiscent of a dumbbell become visible in the telescope . The white dwarf star in the center of the nebula is only 14 bright and can therefore only be observed with larger telescopes.
NGC 6823 is an open star cluster . This is embedded in the emission nebula and H-II area Sh2-86 or NGC 6820. Often Sh2-86 is equated with NGC 6820, although NGC 6820 in the narrower sense only designates a particularly bright node in Sh2-86. NGC 6820 / Sh2-86 and NGC 6823 represent the core area of the even more far-reaching star association Vulpecula OB1. It covers a section of the sky of 4 ° by 2 ° and is about 7,500 light years away.
The NGC object 6885, an open star cluster, is very likely identical to NGC 6882. The discoverer Wilhelm Herschel gave slightly different positions for both numbers, but this was probably just a mistake and he meant one and the same object. In some catalogs, however, both objects are listed as separate clusters or NGC 6882 as a partial cluster of NGC 6885. NGC 6882/6885 is already visible in a small telescope and consists of a few bright, very loosely arranged stars.
The heap Collinder 399 (also called the heap of clothes hangers or Brocchis heap) and Stock 1 can easily be broken down into single stars with an opera glass . Collinder 399 is not a real star cluster, but just a random arrangement of brighter stars that are at different distances. In contrast, the stars on floor 1 also belong together spatially.
The fox also contains some faint galaxies and other planetary nebulae that have been included in the New General Catalog . However, these objects are weaker than the 13th size class and only visible in large telescopes or on long-exposure photographs.
