Orwell Astronomical Society (Ipswich)

Comet 2026 A1 (MAPS)

Comet MAPS, officially C/2026 A1 (MAPS), was discovered on 13 January 2026 by the collaboration of French astronomers Alain Maury, Georges Attard, Daniel Parrott and Florian Signoret, working at the AMACS1 Observatory in the Atacama Desert, Chile. The name of the discovery team, and that of the comet, come from the initial letters of the family names.

The comet was a highly unusual type known as a sungrazer. As the name suggests, sungrazing comets pass extremely close to the Sun and, in consequence, can be very bright, but move very fast, and are often visible for only a few days or, possibly, even hours. Previous bright sungrazing comets included C/2011 W3 (Lovejoy) in 2011 and, before that, C/1965 S1 (Ikeya-Seki) in 1965. A couple of hours before perihelion (closest approach to the Sun), Ikeya-Seki was estimated to be as bright as the first quarter Moon (magnitude -10); the next day, its brilliance had diminished to that of Venus (magnitude -4).

Ephemerides (tables of predictions) for the comet, for 20 March - 13 April, and hourly throughout 04 April, were provided by Dominic Ford’s "in-the-sky" website and are reproduced below. Event details were computed for Ipswich (latitude 52.06°N, longitude 1.16°E); positions were J2000.0.

It is notoriously difficult to predict accurately the brightness of a comet, and the ephemerides raised bopes that MAPS might be visible to the naked eye around the time of perihelion. I advised observers to search for the comet, if it was visible, by holding a hand up towards the Sun to shield the eyes from direct sunlight while looking to the right (before perihelion) or left (after perihelion) of the palm. Telescopic observations with the comet near the Sun were not advised due to the danger of the instrument being knocked and pointing directly at the Sun, or of off-axis heat from the Sun causing damage to the interior of the telescope tube.

For observers preferring an on-line experience, images from the LASCO C3 coronograph aboard the SOHO spacecraft were available via the SOHO website or smartphone app. (SOHO is the the Solar and Heliospheric Observatory, a joint NASA/ESA spacecraft launched in December 1995. LASCO is the Large Angle and Spectrometric COronagraph, one of 11 instruments aboard SOHO. LASCO C3 is a set of three coronographs which image the solar corona from 1.1 to 32 solar radii, i.e. 800,000-22,500,000 km.)

The comet reached perihelion at 14:17 UT on 04 April 2026, at a distance of only 163,000 km above the photosphere. The below image from the LASCO C3 coronograph, taken at 23:06 UT on 03 April, shows the comet on approach to perihelion. In the image, the comet appears at magnitude circa -2, brighter than Saturn (magnitude 0.9, the planet has just left the field of view of the coronograph following solar conjunction), but not as bright as Venus (magnitude -3.9).

Weather in the UK before perihelion was not favourable, and the magnitude of the comet was broadly in line with predictions. No naked eye observations were reported in the UK before perihelion. At perihelion, the comet received approximately 41.8 MW/m² of energy from the Sun. Alas, the comet did not emerge from perihelion, and it appears that the solar energy density was sufficient to vapourise it.

Bill Barton, FRAS

Original: emails 23 February; 01, 11 March; 04, 05 April 2026
Updated: 06 April 2026