In December 2019, an astronomical photograph documented comet 46P/Wirtanen, known as the Christmas Comet of 2018, captured from Treviso in the Veneto region of northern Italy.
Imaging details
The photographer used a Takahashi FSQ85EDX optical tube mounted on an EQ6 Pro equatorial mount. The imaging camera was a QHY163C color sensor. The observation comprised 70 exposures of 60 seconds each, with gain set to 90 and offset to 70, operating at minus 20 degrees Celsius. The total integration time reached approximately 1.17 hours. An IDAS LPS D1 filter was employed to reduce light pollution.
Observing conditions
The image was acquired beneath the light-polluted skies of Treviso, where the Bortle scale reading measured 5, with a Sky Quality Meter value of 19.55 magnitude per square arcsecond. Despite urban light pollution, the long-exposure technique and specialized filtration allowed the comet’s structure to be resolved in detail.
Frequently asked questions
What is comet 46P/Wirtanen?
Comet 46P/Wirtanen is a periodic comet that made a close approach to Earth in December 2018, earning it the designation Christmas Comet of that year.
Why use the IDAS LPS D1 filter?
The IDAS LPS D1 filter was selected to suppress light pollution while preserving the wavelengths of nebular objects, improving image contrast and detail under urban skies.
What do the Bortle and SQM values indicate?
The Bortle scale rating of 5 and SQM measurement of 19.55 indicate suburban sky conditions with moderate light pollution, typical of areas near urban centers.
