The starry sky in February 2024
February 2024 is a leap year with 29 days instead of the usual 28. The leap year was introduced by Julius Caesar in 45 BC, as the seasons had already shifted by three months at that time. To remedy this, the Julian calendar was introduced, which comprised three common years with 365 days and one leap year with 366 days. The additional day was added in February.
Over the centuries, however, it turned out that this regulation was not exact enough; the year length of 365.25 days assumed in Roman times was not correct. By the 16th century, the difference was already 10 days. Pope Gregory XIII then took up the problem, had his astronomers recalculate the length of the year and came up with a length of 365.2425 days. He then carried out a calendar reform in 1582, which became the Gregorian calendar that is used almost worldwide today.
Since then, a leap year has taken place every four years, although not for years that can be divided by 100, but for years that can be divided by 400. There were also ten days in October 1582. October 4, 1582 was followed by October 15, 1582.
Today we know that the year length of 365.2425 days is also not sufficiently precise. 365.2422 days is the correct value up to the fourth decimal place. In practice, however, this does not play a major role; the difference to the solar year is only one day after 3236 years.
The Gregorian calendar was only firmly introduced for the then Duchy of Zweibrücken in 1700, with the omission of 11 days (February 19-29, 1700). However, it had already been used in practice in Zweibrücken since May 1682 (source: Westpfälzische Geschichtsblätter February 1900, No. 2, pages 7 and 8).
SUN AND MOON
Day length continues to increase rapidly in February. While the sun was still 9h 30min above the horizon in Zweibrücken on February 1, it was already 11h 5min on February 29. Similarly, the midday altitude increases from 23.6 degrees at the beginning to 33.1 degrees at the end of the month.
On the 15th of the month, the waxing moon moves past Jupiter. Unfortunately, the closest approach at 3.2 degrees north of the planet remains hidden from us, occurring at 9:00 in the morning. At midnight, the angular separation is 5.5 degrees.
The full moon at the end of the month makes it difficult to see fainter objects.
PLANETS
Mercury is in upper conjunction with the Sun on February 28 and therefore cannot be observed. On the same day Saturn also in conjunction (on the other side of the Sun from the Earth). The planets are only 12 minutes of arc apart on the afternoon of February 28, which is not observable with an angular distance to the sun of only 1.4 degrees.
However, it will be possible to follow the encounter between Mercury and Saturn in the images from the SOHO satellite (https://soho.nascom.nasa.gov/data/realtime/c3/512/).
The visibility conditions of the Venus as a morning star continue to become less favorable, the retreat from the morning sky is already becoming apparent. On February 29, it crosses the horizon line in Zweibrücken at 6:24 a.m., the morning twilight already begins at 6:42 a.m.
The rays of the ever earlier rising sun continue to prevent the morning visibility of the Mars. It cannot be observed in February.
Jupiter has ended its opposition period and continues to accelerate its apparent movement towards the Sun. However, it remains with us as a shining object in the first half of the night. The sunsets shift to the time before midnight. On February 29, it will set at 11:47 pm.
Saturn can no longer be found in the evening twilight. It comes into conjunction with the Sun at the end of the month, but the encounter with Mercury on 28.2. can be seen with the help of a solar satellite (see also entry on Mercury).
Uranus has also ended its opposition period. It can be seen with smaller optical devices at around 57 degrees in the southern sky at nightfall.
STARRY SKY
The twinkling stars of the winter sky have already moved in the direction of the sunset. West shifted, but are still prominent in the night sky.
High about us are Gemini and the inconspicuous constellation of Cancer with its open star cluster, the Praesepe (Latin for The Crib). Far away from disturbing lights, this can already be recognized as a faint patch of nebulosity. Its true beauty can be glimpsed with the aid of binoculars. In Greek mythology, the crab plays a minor role. According to one version, it is said to have assisted the many-headed Hydra in her confrontation with Hercules. However, both were ultimately defeated by the ancient hero. The crab was then transferred to heaven by Hera, wife of Zeus, who was not on good terms with Hercules.
In the East the spring constellations are already attracting attention. Leo, with its main star Regulus, has already risen completely above the horizon.
Still deep in the South the bright star Sirius can still be seen in the Great Dog. Due to its low horizon height, a twinkling with color changes and dancing can often be observed, which is caused by refraction of the light on the flatter and therefore longer path through the Earth's atmosphere.
The following sky view is valid for February 1 at 11 pm, February 15 at 10 pm and February 29 at 9 pm.