Toucan (constellation)
|
Toucan constellation |
|
|---|---|
  |
|
| Latin name | Tucana |
| Latin genitive | Tucanae |
| Abbreviation | Tuc |
| Right ascension | 22 h 08 m 27 s to 01 h 24 m 49 s |
| declination | −75 ° 20 ′ 50 ″ to −56 ° 18 ′ 46 ″ |
| surface | 294,557 deg² rank 48th |
| Completely visible | 15.2 ° N to 90 ° S |
| Observation time for Central Europe | not observable |
| Number of stars brighter than 3 mag | 1 |
| Brightest star (size) | α Tucanae (2.86) |
| Meteor streams | |
|
Neighboring constellations ( clockwise from north ) |
|
| swell | IAU , |
 The constellation of Tucana as seen with the naked eye |
|
The toucan ( Latin Tucana ) is a constellation in the southern sky.
description
The toucan is a less prominent constellation south of the crane . Only one of its stars is brighter than the 3rd magnitude .
In the southeast are the conspicuous Small Magellanic Cloud , a smaller companion galaxy to our Milky Way , as well as the globular cluster 47 Tucanae .
history
The toucan is one of the constellations introduced by Dutch navigators Pieter Dirkszoon Keyser and Frederick de Houtman at the end of the 16th century . It is supposed to represent an exotic bird . Johann Bayer took over the constellation in his 1603 celestial atlas Uranometria .
Celestial objects
Stars
| B. | F. | Names or other designations | m | Lj | Spectral class |
|---|---|---|---|---|---|
| α | 2.87 | 199 | K3 III | ||
| γ | 3.99 | 72 | F1 III | ||
| ζ | 4.23 | 28 | F9 V | ||
| κ | 4.25 | 67 | F6 IV | ||
| β 1 | 4.36 | 140 | B9 V | ||
| ε | 4.49 | 375 | B9 IV | ||
| δ | 4.51 | 267 | B8 V | ||
| β 2 | 4.53 | 172 | A2 V | ||
| ν | 4.91 | 273 | M4 III | ||
| η | 5.00 | 159 | A1 V | ||
| β 3 | 5.07 | 152 | A0 V | ||
| HR 8531 | 5.31 | 67 | F9 V | ||
| ι | 5.36 | 279 | G5 III | ||
| ρ | 5.38 | 133 | F6 V | ||
| λ 2 | 5.45 | 210 | G7 III | ||
| π | 5.50 | 306 | B9 V | ||
| λ 2 | 6.67 |
α Tucanae is an orange star of spectral class K3 III, 199 light years away . It is actually a close binary star system , which however cannot be separated with optical telescopes . The existence of the companion, which orbits the main star in 11.5 years, could only be proven by the exact measurement of its own motion .
Double stars
| system | m | distance |
|---|---|---|
| β | 4.36 / 4.53 / 5.07 | 27 "/ 9 ' |
| λ | 5.45 / 6.67 | 13.8 " |
The second brightest star, β Beta Tucanae, appears in the sky as a star 3.7 m in size . It is actually a multiple star system 140 light years away, made up of six stars. The three brightest are labeled β 1 , β 2 and β 3 . β 1 and β 2 are also known as beta Tucanae A and beta Tucanae C , respectively. Their angular distance in the sky is 27 arc minutes , which corresponds to an actual distance of 1,100 astronomical units (AU). β 1 has a companion that is only 13.5 m bright, Beta Tucanae B , 2.4 arc seconds apart. The companion of β 2 , Beta Tucanae D , is a 6th mag star at a distance of 0.38 arc seconds.
β 3 has a distance of 9 arc minutes from β 1 and β 2 , which corresponds to 0.37 light years. The system consists of two stars measuring 5.8 and 6.0 m . Since they are only 0.1 arcsecond apart, they cannot be separated with the telescope. It is not certain whether β 3 is actually gravitationally connected to the rest of the stars because of the great distance . This is supported by the fact that all stars have the same proper motion.
λ Tucanae is a binary star system 210 light years away. The two components belong to the spectral classes F7 IV and K2 III. Due to their relatively wide angular distance, they can be resolved into single stars with a small telescope.
Variable stars
| star | m | period | Type |
|---|---|---|---|
| θ | 6.06 to 6.15 | 1.18 to 1.45 hours | Short-term variable |
θ Tucanae is a variable star of the Delta-Scuti type, 210 light-years away . Its brightness changes slightly over periods of 1.18 to 1.45 hours.
NGC objects
| NGC | other | m | Type | Surname |
|---|---|---|---|---|
| 104 | 47 Tucanae | 4.0 | Globular clusters | |
| 292 | SMC | 5 | Galaxy | Small Magellanic Cloud |
| 346 | Gas mist | |||
| 371 | Star collection | |||
| 362 | 6.8 < | Globular clusters |
NGC 104 , also known as 47 Tucanae, is the second brightest globular cluster in the night sky after Omega Centauri . It can already be seen with the naked eye and reaches two thirds of the full moon diameter with 20 arc minutes . In a medium-sized telescope with a 15 cm aperture, the cluster can be completely resolved into single stars. NGC 104 stands in close proximity to the Small Magellanic Cloud in the sky, but is much closer at a distance of 14,000 light years.
The Small Magellanic Cloud (SMC) is also a noticeable object in the night sky. It is a smaller companion galaxy to our Milky Way galaxy about 200,000 light years away. It contains several star clusters and nebulae that can already be observed with smaller telescopes , such as the emission nebula NGC 346 or the star cluster NGC 371 .
NGC 362 is a globular cluster 30,000 light years away. With a middle telescope the edge area can be resolved into single stars.
