Astronomy knows no weekends or holidays. There are almost always some interesting events happening in the sky. And the winter holidays are no exception. In the coming days, we will see the maximum of the first powerful meteor shower of 2025 – the Quadrantids.
In this article, you will learn where and when to observe the Quadrantids, their mysterious origin, and the very unusual history of their name.
A constellation that no longer exists
The Quadrantids meteor shower is interesting for several reasons. One of them is its name. Meteor showers are named after the constellations in which their radiant is located – the area in the sky from which meteors fly out. However, if you look at any astronomical reference book or the list of constellations on Wikipedia, you will not find any Quadrant there.
This was not always the case. In 1795, the French astronomer Jérôme Lalande introduced a new constellation called the Quadrans Muralis. It was located in the northern sky between the constellations of Boötes and the Draco. It is believed that its name was inspired by the astronomical instrument of the famous Danish astronomer Tycho Brahe.
At that time, such “vigilantism” in the sky was, in fact, quite common. There was no internationally recognized list of constellations. Therefore, the authors of star atlases and astronomers often introduced new constellations at their discretion to fill in the gaps in the sky or arbitrarily change their boundaries. Ironically, the same fate eventually befell the Quadrans Muralis. While working on his 1801 star atlas Uranographia, Johann Elert Bode reduced the size of the constellation to avoid its intersection with neighboring constellations.
Like many other similar “self-named” constellations, the Quadrans Muralis was not universally recognized by astronomers. However, it was known to the Italian Antonio Brucalassi. On 2 January 1825, Brucalassi described many luminous bodies that flew out of the Quadrans Muralis. In 1839, the astronomers Adolphe Quetelet of the Brussels Observatory and Edward C. Herrick of Connecticut independently suggested that it was a meteor shower that repeated annually. It was named the Quadrantids.
As for the Quadrans Muralis, it did not survive the general purge of the sky organized by the International Astronomical Union in 1922. It canceled most of the self-named constellations. The area of the sky where the Quadrans Muralis was located was divided between the constellations of Boötes, the Draco and Hercules. Nowadays, the name of the Quadrantids remains the only reminder that such a constellation once existed.
The mysterious source of the Quadrantids
Meteor showers occur when the Earth passes through a plume of dust left by a celestial body. In most cases, it is a comet. However, there are exceptions, such as the Geminids, whose source is the tailed asteroid Phaethon, whose origin is still a matter of debate among astronomers.
In the case of the Quadrantids, things are even more interesting because their source is still not known for certain. One of the key features of the flow is that it lasts only six to eight hours at most (for comparison, the famous Perseids last two days). This means that the particle stream that generates it is quite narrow and relatively young. Astronomers estimate that it is only 500 years old.
One of the most popular candidates for the source of the Quadrantids is the asteroid 2003 EH1. It is likely to be a degenerate comet that has come close to the Sun so often that it has lost almost all of its volatile substances. In turn, the asteroid may be associated with the mysterious events of 1490. Back then, Asian astronomers saw a new comet in the sky. The time of its appearance coincided with an incident in the Chinese province of Gansu, when “stones fell like rain”, as described in at least three documents that have survived to this day.
But for now, the connection between all these events and the named celestial bodies is only an assumption. Perhaps in the future, astronomers will be able to dot the i’s and cross the t’s in the question of the origin of the Quadrantids.
When to observe the Quadrantids
The Quadrantids are active from 28 December to 12 January. This year, the peak of their activity will occur on the night of 3 to 4 January. The radiant of the stream is located in the constellation Boötes. According to the International Meteorological Organisation, the ZHR (Zenith Hourly Number) for the Quadrantids will be 110 (slightly higher than that of the Perseids). This number determines how many meteors per hour an observer could see in an “ideal” sky if the radiant were at its zenith.
In 2025, the conditions for observing the Quadrantids will be favorable. On the night of 3-4 January, the lunar disc will be illuminated by only 11%. Therefore, our planet’s satellite will not create strong interference with observations. This is important because the Quadrantids meteors are quite faint, with apparent magnitudes ranging from 3.0 to 6.0. The particles of the stream enter the Earth’s atmosphere at a speed of 41 km/s. This is the average rate for meteor showers. For example, the Geminids move slower and the Perseids move faster.
Since, as we have already mentioned, the peak of the flux does not last long, it is very important to choose the right time for observations. According to forecasts, in 2025, the Quadrantids will peak at around 3:00-4:00 p.m. UTC (10:00-11:00 a.m. UTC-5).
Since the Quadrantids meteors are not particularly bright, you should go out of town to observe them. The Quadrantids radiant will be located in the northeast. To see the maximum number of meteors, observers should lie down with their feet in the direction between southeast and south or west and northwest and look straight up.
