Why is the night of San Lorenzo the night of shooting stars?

There The night of San Lorenzo is the one in which people turn their eyes to the sky to see the stars. Meteors can be seen every clear night of the year, but they can be seen in greater numbers during orbital encounters, when there is a greater quantity of dust ready to enter the atmosphere. In such cases we speak of meteor showers: the August one is just the most popular. Here are the directions to best see the stars with the advice of the Virtual Telescope experts.

Perseids

The phenomenon of the fall is due to the impact with the atmosphere of the dust left by the passages of the Comet Swift-Tuttlediscovered in 1862, whose last passage dates back to 1992 because this periodic hairy star returns approximately every 135 years. They burn and leave a trail in the sky. It was the Italian astronomer Giovanni Schiaparelli, in the 19th century, who connected meteors and comets. The phenomenon is cyclical, visible every year. The Romans interpreted it as a propitious rain. It was the god Priapus who sent it to fertilize the earth of the fields.

The Perseids are active between July 17 and August 24, with a rapid decline after the peak. The maximum concentration of meteors will be visible between August 11 and 12, Sunday and Monday. You can also simply lie down on the ground and look towards the zenith, the center of the starry sky. They are visible throughout the sky. They are seen near the constellation of Perseus, from which they take their name, halfway to the northeast at the end of the night.

Observation 2024

For 2024, observing conditions for the Perseids are favorable. The Moon is new on August 4th, so the sky is dark. The maximum observability is expected between August 11th and 12th: on the evening of the 11th our satellite, not yet in its first quarter, will set shortly after 11 pm, leaving the sky dark for the rest of the night, the most favorable one for seeing meteors. Towards dawn the radiant of the shower will be high in the sky.

The story: why San Lorenzo

Popular tradition connects the astral phenomenon to the martyrdom of San Lorenzo, who was burned in 258, whose anniversary is celebrated on August 10th. The tears recall the burning coals of the martyrdom. The fame of the night of San Lorenzo has also been amplified by a poem: August 10th by Giovanni Pascoli. The poet composed it in memory of his father Ruggero, murdered in mysterious circumstances on August 10, 1867. The incipit is this: “San Lorenzo, I know why so many stars burn and fall in the tranquil air, why such great weeping sparkles in the concave sky.”

How to see shooting stars

You don’t need a telescope, just a dark spot and maybe the luck of the full Moon being far away. The naked eye is undoubtedly ideal for catching the sudden flash of these luminous trails, thanks to its natural panoramic vision. At most, you can observe up to 100 meteors per hour, provided you observe in the second part of the night.

At what time

Any time is fine, but in the second part of the night there is a noticeable increase in meteor activity because at dawn the observer is on the part of the Earth that advances along its orbit towards the cometary dust, it is as if he were seeing from the windshield, rather than the rear window of our planet.

To photograph

You need a camera capable of relatively long exposures. You need to take into account the area of ​​sky framed in the shot, the brightness of the lens used, the ISO sensitivity adopted. This is what the experts at Virtual Telescope explain: «The larger the field of view, the greater the chances of intercepting the trail of a meteor. Super wide-angle lenses (with a focal length of less than 20mm) and “fish-eye” lenses work, especially if they have good brightness (opener than f/4). It is useful to set the camera sensitivity to 800/1600 ISO, compatible with the noise of the camera. In this way, images are collected in sequence, each with an exposure of 30/60 seconds (check the degree of blackening of the sky background, depending on the local light pollution), perhaps pointing in the direction of the radiant».