Autumn sky

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Starry sky in autumn for Central Europe at the end of September at 11 p.m. CEST or at the end of October at 9 p.m. CEST

Autumn sky is the part of the night sky , called the on clear autumn - evenings can be seen. That sight of heaven depends

From the same observation location, 1 month later, we see the same section of sky 2 hours earlier, with each day almost 4 minutes earlier. Because the earth rotates in 23h 56m 04s (a sidereal day ), while our 24-hour day relates to the position to the sun .

For Germany , a mean latitude of 50 ° is usually assumed - the center of gravity of the FRG is 1.2 ° north - and a longitude of 9 ° or 10 ° (near Frankfurt or Würzburg). Almost all rotatable star maps available on the market are calculated for 50 ° / 10 °, which roughly corresponds to the mean for the German-speaking area. For Austria an average of 47.5 ° / 14 ° would be assumed, for Switzerland 47 ° / 8 °.

The picture above right shows the starry sky as it can be seen in mid-October at 9 p.m. CET (in summer time : 10 p.m. CEST) (mid-November at 7 p.m. CET, mid-September at 11 p.m. CET or 12 p.m. CEST). The circumpolar constellations around the north celestial pole can be seen all year round. Outside of this area the autumn sky hardly overlaps with the spring sky , but offers some aspects similar to the summer sky or the winter sky .

Constellations and constellations

The most noticeable constellation in the evening is the large summer triangle descending in the west , which consists of 3 stars of 1st magnitude and runs around the constellation of the swan (northern cross). Its cornerstones are Vega in the lyre (brightest star in the northern sky), Deneb in the swan and Atair in the eagle.

Five star row, high in the east
Andromeda Nebula (M31)

Perseus, Andromeda and Pegasus rise high in the east and southeast, which together form the five-star row and a little later almost reach the zenith . In autumn the bright W of Cassiopeia also stands steeply above us in the northeast. However, we only find its counterpart, the Big Dipper , after taking a closer look at the region below the Pole Star, only a little above the northwest to north horizon. Only in the morning hours does the sky chariot rise again in the northeast.

Deep in the southwest, the constellation of Sagittarius is "saying goodbye" for this year , from where the shimmering ribbon of the Milky Way runs through the middle of the bright summer triangle (eagle, swan) up to the zenith and continues to the northeast via Kassiopeia and Perseus . There the constellations Carter and Taurus are the first messengers of the winter sky . A second important line from Sagittarius to Taurus is the inclined ecliptic , which in autumn only offers us inconspicuous constellations: from the southwest to the left Capricorn and Aquarius, in the southeast the Pisces and in the east the little Aries , which the radiant Jupiter "dressed up" in 2011 . The sun passed through the latter constellations in spring so that we can see it in the night sky in autumn. The star-poor images of the water are completed by the southern fish, whose main star Fomalhaut flashes lonely from the deep south.

Popular observation objects for binoculars and powerful cameras

The autumn sky is not only interesting for free-eyed observation, but - especially towards the beginning of winter - also for the hobby of astrophotography and for owners of high-speed binoculars. Even for cameras with a small telephoto lens , the constellations Perseus and Cassiopeia with their bright nebulae are suitable (especially the double star cluster h / χ Persei), furthermore the Andromeda nebula and the bright star clusters of the Pleiades and Hyades (both Taurus). Later in the night or from December when Gemini and Orion ascend, there are other magnificent objects with a few star clusters (especially M34 to M38 ) and the large gas nebula M41 .

In early autumn, the clouds are still Milky Way in the constellation Swan good to see and for more intense optics still M57 (Ring Nebula in Lyra), the globular cluster M13 and M92 in Hercules, the Dumbbell Nebula and the delicate Star veil of M11 .

With greater experience and from around 10 minutes CCD exposure time, numerous other nebulae from Pegasus to Taurus and (late at night) to Orion come within reach, e.g. B. M15 and M33 (Peg, Tri), M30 (Cap) and the globular clusters M2 (Aqr) and M5 (Snake), further in the east z. B. Horsehead Nebula , Barnard's Loop , Rosette Nebula , some objects in Gemini and the Milky Way Band from there to the high Cassiopeia and west to the Swan.

Numerous double stars (see there) and also bright variable stars complete the "offer", u. a. Algol (whose two stars cover each other every 69 hours) and the long-period Mira , as well as the meteor streams such as the Draconids and Orionids in October and Taurids / Leonids in November.

Shooting stars

After the most famous shooting stars of the Perseids (beginning to mid-August) and the Cygnids (until September), there are only weaker swarms of meteorites in autumn. The most important are:

  • The Piscides from September 1st to 30th,
  • the Draconids , October 6-10
  • southern Taurids , September 10th to November 20th,
  • and Northern Taurids , October 20th to December 10th,
  • the strong current of the Orionids , October 2nd to November 7th (maximum around October 25th)
  • the occasionally strong Leonids , November 6th to 30th,
  • the Puppiden-Veliden , December 1st to 15th,
  • and the always strong Geminids from December 7th to 17th.

Planets

In order to enable the visitors of this page to assign earlier planetary sightings, the data of the two previous years are kept in addition to the current year.

Planets in the autumn sky 2019

  • Mercury is in the evening sky, but despite being elongated by up to 24 ° (October 15-25), it is unobservable. With the passage of Mercury on November 11th - for which many observatories offer guided tours - the planet changes to the west side of the sun and will be from November 18th. visible in the morning sky.
  • Venus stood on August 14. behind the sun and reaches a distance of 20 ° from the sun at the end of October, so that it becomes visible as a shining evening star . At the beginning of December it already sets 1 3/4 customers after the sun sets in Vienna at 5:27 pm, 70 minutes after the sun.
  • Mars is at a distance of 20-30 ° from the sun in the morning sky, but with 2 mag it can hardly be discovered.
  • Jupiter in the Serpent-Bearer dominates the early evening sky until October, together with Saturn, which is 25 ° further to the left. At the beginning of November, however, it sinks in Vienna at 6:50 p.m., in Frankfurt at 7:12 p.m. In December, the giant planet gradually disappears at dusk (and appears in the morning sky after 2 months).
    • Due to the geometry of the orbit, there are only a few passages or shadows cast by the four large moons of Jupiter , the last on October 15 and October 24 and 31.
  • Saturn in Sagittarius follows Jupiter's orbit about an hour and a half later. In mid-November it sets at around 7:45 p.m.
    • On October 5th and 2.11. the moon passes just south of him. The next conjunction is already at dusk and therefore inconspicuous.
    • Saturn's largest moon Titan (7th size) is on October 6th and 22nd. or on November 7th and 23rd in eastern elongation, farthest west, however, on October 14th and 30th. or on November 15 and 1.12.

From 8 p.m., the two outermost planets are - due to the lack of their lighter relatives - the "stars of the night":

  • Uranus in Aries and Neptune in Aquarius can be observed telescopically from late twilight. The discs of the two ice giants measure 3.6 "and 2.5" and can be distinguished from stars even in small telescopes if the air turbulence is not too great. The two culminate in mid-November at 10:30 p.m. and 7:30 p.m. respectively.
    • Uranus came on October 28th. in opposition to the sun, Neptune already in mid-September.

Planets in the autumn sky 2018

  • Mercury is only visible in the morning sky from December 5th . It is also difficult telescopically because of the proximity to the sun.
  • Venus will be visible as a morning star from November 3rd and will initially rise 1 hour before the sun, but at the end of the year it will already be 4 hours, where it reaches the greatest angular distance from the sun at 47 ° .
  • Mars is in the early evening sky and moves from Capricorn to Aquarius and in December to Pisces. After its extreme proximity to the earth at the end of July, its brightness slowly decreases and corresponds to a star of 2nd magnitude at the end of the year .
  • Jupiter is beyond the Sun and will only be visible in the morning sky from mid-December.
  • Saturn slowly wanders through the constellation Sagittarius and is visible until December 10th in the early evening deep in the southwest. Then it is outshone by the sun's halo for 2–3 months.
  • Uranus in Aries is initially visible all night, from mid-December only until 11 p.m. It is only visible to the public under the best of conditions, but in small telescopes it looks more like a 6th mag star with a diameter of 3.6 " .
  • Neptune in Aquarius can only be observed in the first half of the night. Its tiny disc (2.4 ", 7.7 mag) can only be seen when the air is not very calm .

Planets in the autumn sky 2017

  • Mercury is freely visible in the morning sky between September 6th and 26th , and from December 20th. In its evening position in October and November it can only be found in the telescope.
  • Venus has a long visibility as a morning star until early December. Even afterwards you can still see them with a good pair of binoculars - with the appropriate care! - to be found in the daytime sky as a tiny sphere: on December 1st about 10 degrees to the left of the sun, on December 15th about 6 °. In February 2018 she will be evening star again.
  • Mars will be in the morning sky from October. As a reddish star, 2nd magnitude, it wanders through the constellations Leo and Virgo. In mid-December it comes into the scales and rises at 3:20 a.m. Still beyond the sun, the diameter of its disc is slowly increasing from 4 to 5 ". This year, details of its surface can only be seen in telescopes larger than eight-inch .
  • Jupiter in Virgo ends its long evening visibility and disappears behind the rays of the sun. On October 26th he is exactly beyond the sun ( superior conjunction ).
  • Saturn in the Serpent Bearer and Sagittarius can be seen in the evening sky until the end of November. In mid-October it sets in the southwest at 9 p.m. CEST.
  • Uranus in Pisces is visible all night. In small telescopes it appears with a diameter of 3.6 "but only like a 6th mag star .
  • Neptune in Aquarius can only be observed in the first half of the night. Its tiny disc (2.5 ", 8 mag) is only recognizable as such in very calm air .
  • Minor planets No. 1–4 (for small telescope): none near the earth, therefore only 8 to 9 likes brightness . Ceres, discovered on December 31, 1800, moves from Cancer (November 7th near the star Xi Cnc) to Leo, Pallas (in the constellation Fornax) can only be seen in the southern hemisphere because of its great incline. Juno is in the daytime sky, the relatively bright Vesta in the scales. On December 16, it passes just 0.1 ° north of Xi Librae.

News from the sun

Our star of the day is no longer considered a planet (“roaming around”) since Copernicus, but a short paragraph is dedicated to it here for 2014-2017. The solar activity should subside since 2012/13, according to initial predictions, it did, but barely. In 2014 it still showed up to 70 sunspots in 4–9 groups of spots. On December 13, 2014, there was a relative sunspot number of almost 140.

Activity has only decreased since mid-2015, but in 2016 it often reached relative numbers of 100. After an outlier on 5.9. Since October 2017, the maximum values ​​for a good amateur telescope have only been around 40, and the sun is increasingly free from spots. At the beginning of September, however, a huge group of spots with over 100 individual spots was completely unexpected:

September 2017: Strongest X-ray flare in 12 years

Despite the approaching minimum (2019?), A relatively small group of spots formed a huge type F from September 2nd to 5th , causing the relative number to skyrocket to R = 160 and strong solar flares occurred. An X-ray flare X9.3 was the strongest in the current cycle 24, which will probably not happen again 10 years ago.

But already on September 11th the activity level had dropped back to R = 11 (small single spot). Since December, around half of the days have been completely free of spots.

Moon phases 2018

In autumn 2018, the syzygies will come into effect on the following dates (CET):

  • New moon ........... 9.10. 5 a.m., 7.11. 17h, 7.12. 8h
  • First quarter ..... 16.10. 7pm, November 15th 16h, 15.12. 13h
  • Full moon ........... 15.9. 14h, 14.10. 18h, 23.11.7h, 22.12. 19h
  • Last quarter .... 2.10. 11am, 31.10. 18h and 30.11. 1h.

Conjunction with bright stars

Depending on the location of the orbital nodes , the moon can pass close to three first magnitude stars near the ecliptic (Aldebaran, Regulus and Antares).

  • to Aldebaran (Alfa in the bull) on 30.9. at 10 a.m. and on October 27th at 12 o'clock; the other passages are during the day.

Well observable conjunctions of planets in the morning sky:

  • Mercury on October 5th to Spica (Alfa Virginis), 2 ° north
  • Mercury on November 9th and 21.12. to Antares (Alfa in Scorpio), 2 ° or 6 ° north
  • Jupiter on December 20th at Antares, 5 ° north.

Seasons

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