The Indian Space Research Organisation’s Physical Research Laboratory (PRL) has recently conducted detailed observations of the interstellar comet 3I/Atlas, which is currently traversing the inner solar system towards the Sun. Utilizing the PRL’s 1.2-meter telescope, scientists have captured significant data regarding this enigmatic comet, including its tail structure.
3I/Atlas is making its way out of the inner solar system following its closest approach to the Sun, known as perihelion. During this close examination, experts noted the presence of a near-circular coma surrounding the comet. The coma is an expansive, glowing region of gas and dust that forms around the comet’s nucleus as it approaches the Sun. This phenomenon occurs as the Sun’s heat causes the frozen ices in the nucleus to vaporize. This process, known as sublimation, releases gas and dust, which creates a diffuse cloud around the nucleus.
From the current vantage point on Earth, the dust tail, if it exists, would be oriented away from the Sun, trailing behind the comet. The imaging efforts included a wide-field multi-band capture which may reveal the ion tail as well.
In addition to imaging, the scientists also obtained spectral data of the comet's light before the onset of morning twilight. This spectrum revealed notable emission features typical of comets within our solar system, including the CN, C2, and C3 bands prominent in the shorter wavelengths. These emissions provide insights into the chemical composition of the comet and its activity.
The rate at which gas is released from the nucleus of the comet into the coma, known as the production rate, is a crucial indicator of the comet’s level of activity. This rate fluctuates depending on various factors including the comet's distance from the Sun and its intrinsic properties. For 3I/Atlas, the calculated production rates for the major emission bands were around 10^25 molecules per second, a significant finding that illustrates the comet’s dynamic behavior.
These observations are an important contribution to the understanding of not just 3I/Atlas but also the broader study of comets and their behaviors as they traverse the solar system.