Comet Chasing - Comets Visible in October 2026, by Aperture

There is one comet visible in small telescopes from both hemispheres this month, 10P/Tempel. ten more are visible in larger telescopes. See the Observing Synopses for which comets are visible from your latitude, the best dates and the time of night.

Visibility predictions here use SkyTools code that accounts for magnitude, coma diameter, and degree of condensation from recent observations (rather than magnitude alone.) When we say a comet needs a 14-inch scope, it means the comet is detectable in the eyepiece at that aperture from a Bortle 5 (country/suburban) site (or a dark site if indicated).

General Comet Information

10P/Tempel is a periodic comet with an orbital period of 5.4 years. Perihelion was on August 2, 2026 at a distance of 1.4 AU.
161P/Hartley-IRAS is a Hallet-type periodic comet with an orbital period of 21.5 years. It will reach perihelion in late November when it is predicted to reach maximum brightness of magnitude 12.5 in early November.
220P/McNaught is a periodic comet with an orbital period of 5.5 years. It had a new outburst early last month. As of August 7, it had brightened to magnitude 7, the coma had grown to 7.5 arc minutes, and there was a 21 arc minute tail. It has been fading regularly ever since. As of September 1, it is 11th magnitude.
169P/NEAT is a periodic comet with an orbital period of 4.22 years. It passed perihelion on September 21. It passed within 0.17 AU of the Earth on August 11.
C/2026 A2 (Bok) will reach perihelion in late December. It is predicted to reach maximum brightness of magnitude 13.5 in early December.
C/2024 T5 (ATLAS) will pass perihelion in early May 2027. It is currently predicted to reach maximum brightness of magnitude 13.3 in mid April.
88P/Howell is a periodic comet with an orbital period of 5.5 years. It passed perihelion in March 2026 at a distance of 1.4 AU.
29P/Schwassmann-Wachmann has frequent outbursts, typically resulting in a brightening of 1-4.0 magnitudes. It varies in its distance from the Sun from 5.8 AU (at perihelion) to 6.3 AU (at aphelion), which is an unusually small variation for a comet, and remains quite far from the sun at all times. This means that it can be observed more or less continuously. See [Mission 29P](https://britastro.org/section_information_/comet-section-overview/mission-29p-2) from the BAA for up to date information.
C/2024 J3 (ATLAS) will pass perihelion in late November. It is predicted to reach maximum brightness of magnitude 14.5 in early November.
78P/Gehrels is a periodic comet with an orbital period of 7.2 years that passed perihelion in late June. It is predicted to obtain maximum brightness of magnitude 13 in mid November.
260P/McNaught is a periodic comet with an orbital period of 6.9 years that passed perihelion in early August.
C/2025 R3 (PANSTARRS) passed perihelion on April 19.
C/2024 R4 (PANSTARRS) will reach perihelion in late October 2027. It is predicted to reach maximum brightness of magnitude 14 in late February 2028.
C/2014 UN271 (Bernardinelli-Bernstein) is an interesting Oort cloud comet that was reported as a result of the Dark Energy Survey. Soon after it was made public, images showed a cometary coma. Discovery credit goes to Pedro Bernardinelli and Gary Bernstein. This is a remarkable comet that was at 29 AU in 2014, with a perihelion of 10.9 AU in 2031. Its orbit extends out to 40,000 AU! It was unusually bright for its distance. HST observations that isolate the nucleus estimate the diameter to be between 120 and 140 km, making this possibly the largest comet nucleus yet measured. Because of its distant perihelion, this comet is not expected to become bright enough to be visually observed except in large instruments, and not until the end of the decade, but it is likely going to be the subject of intense scientific scrutiny.

Comets that have apparently disintegrated: C/2026 A1 (MAPS), SWAN26B, C/2025 F2, C/2024 G3, C/2024 S1 (ATLAS), C/2022 S3 (PANSTARRS), C/2021 P4 (ATLAS), C/2020 Q1 (Borisov), C/2020 P1 (NEOWISE), and C/2019 Y4 (ATLAS). Beware that various sources often fail to keep track of whether a comet still exists!

Comet Visibility in the Eyepiece

Magnitude alone is a poor guide to whether a comet can be seen. This page uses the SkyTools visibility model, which also considers coma diameter, degree of condensation, sky brightness, the moon, and the aperture in use. The dates below are the nights the comet should be perceptible — visible with reasonable confidence, but not necessarily easy. The last night listed is the least certain, since it is the night the comet crosses that threshold; expect it to move by a day either way with your sky and your optics. The times given are the optimum time to look. But always remember, comets are like cats. They both have tails and do what they want, and not always what we expect. This is one of the things that makes comet chasing interesting!

Observing Synopses for October

Times are local standard time. Add one hour where daylight saving or summer time is in effect. Times are approximate and vary with your latitude, so go out well before the time given. .

10P/Tempel: An evening comet visible in small telescopes at a dark site

This comet begins the month in Piscis Austrinus at magnitude 10.1. Look for a 6.5' coma, center much brighter than edges, though still diffuse. It should fade rapidly, moving into Sculptor by month's end. The best visibility is early in the month as seen from the southern hemisphere. FINDER CHART

Visibility of 10P/Tempel by latitude, October 2026
Latitude	Visibility
55° N	Not perceptible.
40° N	Perceptible in a 10-inch (25 cm) telescope from a dark site in the evening from the 1st through the 4th, low in the south throughout. In a 12.5-inch (32 cm) telescope it is perceptible from the 1st through the 7th.
Equator	Perceptible in a 4-inch (10 cm) telescope from a dark site in the evening on the 1st and 2nd. In a 6-inch (15 cm) telescope it is perceptible from the 1st through the 8th.
30° S	Perceptible in a 4-inch (10 cm) telescope from a dark site in the evening from the 1st through the 4th. In a 6-inch (15 cm) telescope it is perceptible from the 1st through the 10th.

161P/Hartley-IRAS: An evening comet visible in a 6-inch (15 cm) telescope at a dark site

This comet begins the month in Aquarius at magnitude 11.4. Look for a 2.5' coma, center much brighter than edges, though still diffuse. It should fade by about 0.7 magnitudes, moving into Aquila by month's end. The best visibility is early in the month. FINDER CHART

Visibility of 161P/Hartley-IRAS by latitude, October 2026
Latitude	Visibility
55° N	Perceptible in a 6-inch (15 cm) telescope from a dark site in the evening from the 3rd through the 18th, then on the 30th and 31st, fairly high at first, climbing higher as the month goes on.
40° N	Perceptible in a 6-inch (15 cm) telescope from a dark site in the evening from the 1st through the 18th, then from the 28th through the end of the month, fairly high at first, climbing higher as the month goes on.
Equator	Perceptible in a 6-inch (15 cm) telescope from a dark site from the 1st/2nd through the 15th/16th, then from the 27th/28th through the end of the month, moving from near midnight to the evening as the month goes on.
30° S	Perceptible in a 6-inch (15 cm) telescope from a dark site from the 1st/2nd through the 15th/16th, then on the 27th/28th, high at first, moving from near midnight to the evening and sinking lower as the month goes on. In an 8-inch (20 cm) telescope it is perceptible from the 1st/2nd through the 16th/17th, then from the 27th/28th through the end of the month.

C/2026 A2 (Bok): A northern hemisphere evening comet visible in a 6-inch (15 cm) telescope at a dark site

This comet begins the month in Draco at magnitude 13.6. Look for a 45" coma, condensation is a bright diffuse spot at center of coma. It should brighten by about 0.9 magnitudes, moving into Cygnus by month's end. The best visibility is late in the month as seen from far-northern latitudes. FINDER CHART

Visibility of C/2026 A2 (Bok) by latitude, October 2026
Latitude	Visibility
55° N	Perceptible in a 6-inch (15 cm) telescope from a dark site in the pre-dawn sky from the 17th through the 20th, then from the 29th through the end of the month. In an 8-inch (20 cm) telescope it is perceptible from the 1st/2nd through the 24th/25th, then from the 27th/28th through the end of the month.
40° N	Perceptible in a 6-inch (15 cm) telescope from a dark site in the evening from the 28th through the end of the month. In an 8-inch (20 cm) telescope it is perceptible from the 1st through the 21st, then from the 27th through the end of the month.
Equator	Perceptible in a 6-inch (15 cm) telescope from a dark site in the evening from the 27th through the end of the month, fairly high in the north throughout. In an 8-inch (20 cm) telescope it is perceptible from the 12th through the 20th, then from the 26th through the end of the month.
30° S	Not perceptible.

C/2024 T5 (ATLAS): A morning comet visible in a 10-inch (25 cm) telescope at a dark site

This comet begins the month in Lepus at magnitude 13.8. Look for a 40" coma, diffuse condensation at center. It should brighten slowly. The best visibility is late in the month. FINDER CHART

Visibility of C/2024 T5 (ATLAS) by latitude, October 2026
Latitude	Visibility
55° N	Perceptible in a 14-inch (36 cm) telescope from a dark site in the pre-dawn sky from the 15th through the 24th, fairly high in the south throughout. In a 16-inch (41 cm) telescope it is perceptible from the 6th through the 24th.
40° N	Perceptible in a 12.5-inch (32 cm) telescope from a dark site in the pre-dawn sky from the 6th through the 24th, fairly high throughout.
Equator	Perceptible in a 10-inch (25 cm) telescope from a dark site in the pre-dawn sky from the 8th through the 24th. In a 12.5-inch (32 cm) telescope it is perceptible from the 4th/5th through the 24th/25th, then on the 31st/November 1st.
30° S	Perceptible in a 10-inch (25 cm) telescope from a dark site from the 6th/7th through the 23rd/24th, then on the 30th/31st and 31st/November 1st, moving from before dawn to near midnight as the month goes on. In a 12.5-inch (32 cm) telescope it is perceptible from the 3rd/4th through the 24th/25th, then from the 29th/30th through the end of the month.

C46K1R1: An evening comet visible in a 10-inch (25 cm) telescope at a dark site

This comet has not yet been officially designated by the Minor Planet Center despite a large number of observations for over a month. It begins the month in Corona Borealis at magnitude 13.3. Look for a 40" , uniformly diffuse coma. It should fade by about 1.0 magnitudes, moving into Triangulum Australe by month's end. The best visibility is early in the month. FINDER CHART

Visibility of C46K1R1 by latitude, October 2026
Latitude	Visibility
55° N	Perceptible in a 12.5-inch (32 cm) telescope from a dark site in the evening from the 1st through the 5th, fairly high throughout.
40° N	Perceptible in a 10-inch (25 cm) telescope from a dark site in the evening from the 3rd through the 5th, fairly high throughout. In a 12.5-inch (32 cm) telescope it is perceptible from the 1st through the 8th.
Equator	Perceptible in a 10-inch (25 cm) telescope from a dark site in the evening from the 4th through the 12th, fairly high throughout. In a 12.5-inch (32 cm) telescope it is perceptible from the 1st through the 13th.
30° S	Perceptible in a 10-inch (25 cm) telescope from a dark site in the evening from the 8th through the 13th, fairly high in the west throughout. In a 12.5-inch (32 cm) telescope it is perceptible from the 5th through the 14th.

29P/Schwassmann-Wachmann: A northern hemisphere morning comet visible in a 16-inch (41 cm) telescope at a dark site

This comet begins the month in Virgo at magnitude 14.2. Look for a 5" coma. It should remain constant. The best visibility is late in the month. FINDER CHART

Visibility of 29P/Schwassmann-Wachmann by latitude, October 2026
Latitude	Visibility
55° N	Not perceptible.
40° N	Perceptible in a 24-inch (61 cm) telescope from a dark site in morning twilight from the 30th through the end of the month, very low in the east throughout.
Equator	Perceptible in a 16-inch (41 cm) telescope from a dark site in morning twilight on the 31st and November 1st, low in the east throughout. In an 18-inch (46 cm) telescope it is perceptible from the 29th through the end of the month.
30° S	Not perceptible.

C/2024 J3 (ATLAS): A northern hemisphere evening comet visible in an 18-inch (46 cm) telescope at a dark site

This comet begins the month in Lyra at magnitude 14.1. Look for a 55" coma, diffuse condensation at center. It should remain constant. The best visibility is early in the month as seen from the northern hemisphere. FINDER CHART

Visibility of C/2024 J3 (ATLAS) by latitude, October 2026
Latitude	Visibility
55° N	Perceptible in an 18-inch (46 cm) telescope from a dark site from the 1st/2nd through the 17th/18th, then on the 30th/31st and 31st/November 1st, moving from evening twilight to the evening as the month goes on.
40° N	Perceptible in an 18-inch (46 cm) telescope from a dark site in the evening from the 1st through the 15th, then from the 28th through the end of the month.
Equator	Perceptible in a 24-inch (61 cm) telescope from a dark site in the evening from the 1st through the 15th, then from the 27th through the end of the month, high at first, sinking lower as the month goes on.
30° S	Not perceptible.

78P/Gehrels: A morning comet visible in an 18-inch (46 cm) telescope at a dark site

This comet begins the month in Gemini at magnitude 14.6. Look for a 30" coma, diffuse condensation at center. It should remain constant, moving into Cancer by month's end. The best visibility is late in the month. FINDER CHART

Visibility of 78P/Gehrels by latitude, October 2026
Latitude	Visibility
55° N	Perceptible in an 18-inch (46 cm) telescope from a dark site in the pre-dawn sky on the 23rd and 24th. In a 24-inch (61 cm) telescope it is perceptible from the 6th through the 24th.
40° N	Perceptible in an 18-inch (46 cm) telescope from a dark site in the pre-dawn sky from the 8th through the 24th.
Equator	Perceptible in an 18-inch (46 cm) telescope from a dark site in the pre-dawn sky from the 8th through the 24th.
30° S	Perceptible in a 24-inch (61 cm) telescope from a dark site in the pre-dawn sky from the 6th through the 24th, fairly high throughout.

260P/McNaught: A northern hemisphere morning comet visible in an 18-inch (46 cm) telescope at a dark site

This comet begins the month in Auriga at magnitude 15.0. Look for a 25" coma, condensation is a diffuse spot in coma center; moderately condensed. It should fade slowly. The best visibility is early in the month as seen from the northern hemisphere. FINDER CHART

Visibility of 260P/McNaught by latitude, October 2026
Latitude	Visibility
55° N	Perceptible in a 24-inch (61 cm) telescope from a dark site in the pre-dawn sky from the 6th through the 24th.
40° N	Perceptible in an 18-inch (46 cm) telescope from a dark site in the pre-dawn sky on the 8th. In a 24-inch (61 cm) telescope it is perceptible from the 6th through the 24th.
Equator	Perceptible in a 24-inch (61 cm) telescope from a dark site in the pre-dawn sky from the 6th through the 23rd.
30° S	Not perceptible.

220P/McNaught: An all night comet visible in a 24-inch telescope at a dark site

This comet begins the month in Taurus at magnitude 13.2. Look for a 2' coma, center much brighter than edges, though still diffuse. It should fade slowly, moving into Cetus by month's end. The best visibility is early in the month. FINDER CHART

Visibility of 220P/McNaught by latitude, October 2026
Latitude	Visibility
55° N	Not perceptible.
40° N	Perceptible in a 24-inch (61 cm) telescope from a dark site after midnight from the 5th/6th through the 9th/10th.
Equator	Perceptible in a 24-inch (61 cm) telescope from a dark site from the 3rd/4th through the 18th/19th, moving from near midnight to after midnight as the month goes on.
30° S	Perceptible in a 24-inch (61 cm) telescope from a dark site after midnight from the 3rd/4th through the 9th/10th.

169P/NEAT: A northern hemisphere morning comet visible in a 24-inch telescope at a dark site

This comet begins the month in Sextans at magnitude 12.4. Look for a 1.5' coma, diffuse condensation at center. It should fade rapidly, moving into Leo by month's end. The best visibility is early in the month. FINDER CHART

Visibility of 169P/NEAT by latitude, October 2026
Latitude	Visibility
55° N	Not perceptible.
40° N	Perceptible in a 24-inch (61 cm) telescope from a dark site in morning twilight from the 2nd through the 9th, low in the east throughout.
Equator	Perceptible in a 24-inch (61 cm) telescope from a dark site from the 1st/2nd through the 11th/12th, fairly high in the east at first, moving from morning twilight to before dawn as the month goes on.
30° S	Not perceptible.

Summary Data for This Month's Telescopic Comets

Comets reaching magnitude 16 or brighter during October 2026. Constellation is where the comet stood on the first of the month. The last column gives the date of the most recent observation used to compute these values; a question mark marks values extrapolated from observations more than a month old.
Comet	Constellation	October 1st		October 15th		October 31st		Observations as of (UT)
Comet	Constellation	Mag	Diam	Mag	Diam	Mag	Diam	Observations as of (UT)
10P/Tempel	Piscis Austrinus	10.1	6.3′	11.2	5.3′	12.5	4.3′	2026 September 22
161P/Hartley-IRAS	Aquarius	11.4	2.7′	11.5	2.2′	12.1	1.5′	2026 September 30
169P/NEAT	Sextans	12.4	1.7′	13.7	1.3′	15.0	1.1′	2026 September 25
220P/McNaught	Taurus	13.2	2.0′	13.3	2.0′	13.6	2.0′	2026 September 29
C46K1R1	Corona Borealis	13.3	39″	13.0	36″	14.3	19″	2026 October 1
C/2026 A2 (Bok)	Draco	13.6	43″	13.1	47″	12.7	51″	2026 October 1
C/2024 T5 (ATLAS)	Lepus	13.8	38″	13.7	40″	13.5	43″	2026 September 23
C/2024 J3 (ATLAS)	Lyra	14.1	55″	14.1	54″	14.2	53″	2026 September 22
29P/Schwassmann-Wachmann	Virgo	14.2	6″	14.2	6″	14.2	6″	2026 August 21
78P/Gehrels	Gemini	14.6	32″	14.5	34″	14.5	37″	2026 September 29
260P/McNaught	Auriga	15.0	27″	15.1	27″	15.3	28″	2026 September 30
88P/Howell	Aries	15.0	55″	15.3	55″	15.8	53″	2026 September 23
C/2024 R4 (PANSTARRS)	Cygnus	15.1?	30″?	15.1?	30″?	15.1?	30″?	2026 July 28
C/2023 R1 (PANSTARRS)	Libra	15.3	34″	15.5	32″	15.7	31″	2026 September 22
63P/Wild	Corvus	16.0?	35″?	16.2?	34″?	16.4?	34″?	2026 August 2
112P/Urata-Niijima	Auriga	16.0	1.4′	16.0	1.5′	16.1	1.5′	2026 September 23
C/2025 Y1 (ATLAS)	Virgo	16.0?	20″?	15.9?	20″?	15.7?	21″?	2026 July 26
2P/Encke	Pisces	17.4	23″	16.7	27″	15.9	29″	2026 September 30

* In solar conjunction and generally not visible

For information about specific comets see Gary W. Kronk's Cometography

Maintained by Greg Crinklaw, since 2003.

Comet Chasing in October 2026