12P

12P/Pons-Brooks

A Halley-type periodic comet of period 71 years, detailed information can be found here. It passed through the inner solar system in 2024 reaching perihelion on April 21 at a distance of 0.78 AU. Prior to perihelion its position north of the ecliptic made viewing more favourable for northern hemisphere observers, and the converse applied after perihelion. It was never a bright object reaching a maximum integrated magnitude of around 4.5. It made its closest approach to Earth on 2024 June 2 (1.55 AU) when it was around magnitude 6.5.

	2024 April 1: photographed under light-polluted skies from Fort Stockton, Texas, USA, against the stars of Aries when it was about magnitude 4.8; tripod-mounted Canon 5D MkII + 28-70mm* f2.8 zoom lens, at 63mm and f4, ISO2000. Seventy-four x 5 sec exposures were stacked and combined for just over 6 minutes of total accumulation. Field of view ~24°x16°. * COBS database: https://www.cobs.si/obs/comet/484/
	2024 April 30: photographed under dark skies near Echuca, northern Victoria, against the stars of Taurus when it was about magnitude 4.8, though atmospheric extinction was substantial due to low elevation of 15º; Canon 5D MkII + 300mm f/2 lens, at f4, on an NEQ6 Pro mount tracking the sky, ISO 1600. Thirty seven x 20 second exposures were stacked and combined to optimise the comet and the background stars; total accumulation = 12.3 minutes. Field of view ~3.9°x2.6°..Note the beautifully structured blue ion tail. COBS database: https://www.cobs.si/obs/comet/484/
	2024 May 1; magnitude about 4.9 against the stars of* Taurus, though atmospheric extinction was substantial due to low elevation and poor transparency; location and equipment as per April 30. Thirty six x 20 second exposures were stacked and combined to optimise the comet and the background stars; total accumulation = 12 minutes. Field of view ~3.9°x2.6°. Note the blue ion tail is present, but was impacted by the adverse observing conditions. * COBS database: https://www.cobs.si/obs/comet/484/
	2024 May 2; magnitude about 4.9 against the stars of* Taurus, though atmospheric extinction was substantial due to low elevation and poor transparency; equipment as per April 30. Thirty eight x 20 second exposures stacked and combined to optimise the comet and the background stars; total accumulation = 12.6 minutes. Field of view ~3.9°x2.6°. * COBS database: https://www.cobs.si/obs/comet/484/
	2024 May 27; photographed under dark skies at Beechworth, northern Victoria, against the stars of Lepus when at magnitude about 5.9; equipment as per April 30. Fifty x 30 second exposures were stacked and combined to optimise the comet and the background stars; total accumulation = 25 minutes. Field of view ~5.3°x3.5°. The comet's appearance has changed dramatically over the month, but the change is simply an effect of perspective as we see the comet almost edge-on as the Earth passes through the comet's orbital plane. COBS database: https://www.cobs.si/obs/comet/484/

	2024 April 1: photographed under light-polluted skies from Fort Stockton, Texas, USA, against the stars of Aries when it was about magnitude 4.8; tripod-mounted Canon 5D MkII + 28-70mm* f2.8 zoom lens, at 63mm and f4, ISO2000. Seventy-four x 5 sec exposures were stacked and combined for just over 6 minutes of total accumulation. Field of view ~24°x16°. * COBS database: https://www.cobs.si/obs/comet/484/
	2024 April 30: photographed under dark skies near Echuca, northern Victoria, against the stars of Taurus when it was about magnitude 4.8, though atmospheric extinction was substantial due to low elevation of 15º; Canon 5D MkII + 300mm f/2 lens, at f4, on an NEQ6 Pro mount tracking the sky, ISO 1600. Thirty seven x 20 second exposures were stacked and combined to optimise the comet and the background stars; total accumulation = 12.3 minutes. Field of view ~3.9°x2.6°..Note the beautifully structured blue ion tail. COBS database: https://www.cobs.si/obs/comet/484/
	2024 May 1; magnitude about 4.9 against the stars of* Taurus, though atmospheric extinction was substantial due to low elevation and poor transparency; location and equipment as per April 30. Thirty six x 20 second exposures were stacked and combined to optimise the comet and the background stars; total accumulation = 12 minutes. Field of view ~3.9°x2.6°. Note the blue ion tail is present, but was impacted by the adverse observing conditions. * COBS database: https://www.cobs.si/obs/comet/484/
	2024 May 2; magnitude about 4.9 against the stars of* Taurus, though atmospheric extinction was substantial due to low elevation and poor transparency; equipment as per April 30. Thirty eight x 20 second exposures stacked and combined to optimise the comet and the background stars; total accumulation = 12.6 minutes. Field of view ~3.9°x2.6°. * COBS database: https://www.cobs.si/obs/comet/484/
	2024 May 27; photographed under dark skies at Beechworth, northern Victoria, against the stars of Lepus when at magnitude about 5.9; equipment as per April 30. Fifty x 30 second exposures were stacked and combined to optimise the comet and the background stars; total accumulation = 25 minutes. Field of view ~5.3°x3.5°. The comet's appearance has changed dramatically over the month, but the change is simply an effect of perspective as we see the comet almost edge-on as the Earth passes through the comet's orbital plane. COBS database: https://www.cobs.si/obs/comet/484/