Home=Current Comets
| The German Group
| Tutorials
| Archive: Fainter Comets 2024
| Projects, publications
| Images
| Contact
Just three days later, on Sep. 10, 2023, the PANSTARRS team succeeded in discovering a comet near the border of the constellations Cetus/Eridanus. Comet C/2023 R2 (PANSTARRS) presented a highly condensed 8" coma of total magnitude 20.0 and a 5" tail in p.a. 150°. The comet will pass perihelion at the solar distance of 0.91 AU on Aug. 12, 2024, expected to peak at magnitude 13.0 during those days (CBET 5301). It should be brighter than 16 mag between mid-May and end of October 2024. During this period it will move through the constellations Taurus, Orion, Monoceros, Canis Minor, Cancer/Hydra, Sextans (perihelion), Leo, Virgo and Serpens Caput. Unfortunately, the comet will experience elongations of less than 24° during this period, so will be a challenging object.
The comet could only be followed until April 2024, when it had just brightened to 17 mag.
--------------------
On their images taken on Nov. 5, 2023 with two 28cm-SC and CMOS cameras at the Hakos Astrofarm, the Spanish amateur Jordi Camarasa and the Swedish amateur Grzegorz Duszanowicz discovered a comet of magnitude 18.5, showing a tail, in the constellation Horologium. Follow-up observations of comet C/2023 V4 (Camarasa-Duszanowicz) showed a strongly condensed, 8" coma of total magnitude 18.5 and a 0.3' long curved tail in p.a. 340°. The comet will pass perihelion at the solar distance of 1.12 AU on May 30, 2024, but will then unfortunately be on the opposite side of the sun relative to Earth and therefore difficult to observe. The comet is expected to peak at magnitude 14.0-14.5 in June 2024 (CBET 5315). It should be brighter than 16 mag between March and August 2024. During this period it will move through the constellations Cetus, Aries, Perseus, Auriga, Lynx, Ursa Major and Canes Venatici. For Central European locations it is positioned very low above the western to northwestern evening horizon until mid-June. It then begins to rise, reaching a maximum altitude of 30° at the end of July.
The comet actually reached magnitude 10.7 at the start of June 2024, based on 101 observations by 26 observers, most of which were achieved post-perihelion. The brightness development can be well represented with the parameters
m0 = 8.5 mag / n = 5.5.
The coma diameter increased from 1.5' (125,000 km) at the beginning of June 2024 to 2.8' (210,000 km) in mid-July. Until mid-September it had decreased to 0.3' (35,000 km). The degree of condensation was constant at DC 3-4. Post-perihelion a tail of up to 6' (1 mio. km) length could be detected via CCD.
Total Brightness and Coma Diameter
--------------------
On Jan. 16, 2024 the LEMMON project discovered an asteroidal object of magnitude 20 in the constellation Eridanus, which turned out to be a comet, according to follow-up observations. Comet C/2024 B1 (LEMMON) showed a highly condensed 7" coma of total magnitude 20.5m. It will pass perihelion on Oct. 7, 2024 in the solar distance of 1.63 AU, expected to reach magnitude 16.0 (CBET 5344). During the weeks around perihelion it will move through the constellations Ursa Major, Canes Venatici, Bootes and Corona Borealis. At mid-European locations it can be seen at altitudes of less than 25° above the northwestern evening horizon and the northeastern morning horizon.
Based on 22 observations from 9 observers the brightness development can be represented reasonably well by the parameters
m0 ≈ 11.0 mag / n ≈ 3,
indicating a maximum brightness of 14.0 mag in mid-November 2024. The medium-condensed coma reached a maximum diameter of 1.5'.
--------------------
On Feb. 14, 2024, an asteroidal object with an estimated total magnitude of 16.5-17.0 was discovered in the constellation Ara in the course of the ATLAS project. During the following days it was recognized as a comet. Comet C/2024 C4 (ATLAS) showed a highly condensed, 25" coma of total magnitude 15.8, and a 30" tail in p.a. 227°. The comet had already passed perihelion at a solar distance of 1.47 AU on Jan. 30, 2024 when it should have been of magnitude 16.0 (CBET 5354, various MPECs). Between the start of February and the end of April the comet should have been brighter than 16 mag, with peak brightness expected at 15.2 mag at the start of April, because the comet will still be approaching Earth until mid-April. During this period it will move in a northerly direction through the constellations Ara, Scorpius, Ophiuchus and Serpens. For Central European locations it will appear above the southern morning horizon during the first week of March, thereafter rapidly gaining altitude during the following weeks, thereby fading slowly.
Based on only 24 observations from 10 observers the brightness parameters can be very roughly determined as
m0 = 11.0 mag / n = 6.5.
The comet peaked at about 14.5 mag in mid-March 2024, thereafter fading to 16.5 mag by the beginning of May. The extremely diffuse coma reached a diameter of about 0.8'.
--------------------
On Dec. 25/26 Martin Masek discovered a 14-15 mag comet in the constellation Indus in images taken with a 300mm telephoto lens (which is part of the Pierre Auger Observatory) in the course of his self-initiated search program. Comet C/2024 Y1 (Masek) showed a significantly condensed inner coma of approximately 15" and an outer coma of diameter 1.4', whose total magnitude he determined to be 15.0 mag. In addition the comet showed a 1.6' long, semicircular tail at p.a.=120...300°. The comet passed perihelion at the solar distance of 0.83 AU on Nov. 26, 2024, when it should have been of magnitude 15.0 mag (CBET 5487). Because it will approach Earth post-perihelion its brightness should remain fairly constant for several weeks. The comet was positioned in the far-southern sky during the most interesting weeks.
Only a dozen CCD observations can be used for a rough analysis. These indicate that the comet peaked at 14.5 mag at the end of December 2024, with the brightness decreasing to 16.0 mag by the end of January 2025. The brightness parameters can be roughly determined as
m0 ≈ 14.5 mag / n ≈ 3.
The apparent coma diameter measured 1.5-2.0'.
--------------------
Comet 32P/Comas Sola (P=9.73a) will pass perihelion at the solar distance of 2.02 AU on Apr. 20, 2024, but will come closest to Earth on Nov. 30, 2023. As a result the comet is expected to peak at magnitude 14.0 at the beginning of February 2024. The comet should be brighter than 16 mag between October 2023 and August 2024. During this period it will move through the constellations Aries, Taurus, Auriga, Gemini, Cancer and Leo. From central European locations the comet will appear in the night sky at first, but will change to the evening sky in December 2023 and will disappear above the Northwestern horizon in February 2024.
Despite a maximum brightness of only 14.0 mag in the second half of January 2024, 75 observations from 24 observers can be used for the analysis, most of which are CCD observations. The brightness development can be described well with the parameters
m0 = 7.3 mag / n = 6.7.
The coma diameter increased from 0.4' (30,000 km) at the beginning of the apparition to the maximum of 1.3' (100,000 km) in January/February 2024. The number of estimates of the degree of condensation is very small, but they seem to indicate a decrease from DC 7 to DC 3 during the apparition. A tail of up to 2-3' (1.25 mill. km) length was detected throughout the apparition. It was directed towards the WSW until the end of November, thereafter towards the East.
Total Brightness and Coma Diameter
--------------------
Comet 130P/McNaught-Hughes (P=6.22a) passed perihelion at the solar distance of 1.82 AU on Apr. 14, 2024. During the second half of the year it moves along the border of the constellations Cetus/Pisces.
Regarding its relative faintness this comet was observed surprisingly intensively. After all, 94 CCD observations from 16 observers can be used for the analysis. However, the observations exhibit a significant scatter, so that the brightness parameters can only be roughly determined as
m0 = 11.5 mag / n = 3.
Thus the comet peaked at 14.9 mag in September 2024. Until December it had faded to 16.0 mag. The comet showed a moderately condensed (DC 4) coma with a constant diameter of 0.9' (70,000 km). Between July and December 2024 a tail of up to 9' (2 mio. km) length could be detected, which was constantly oriented towards West.
Total Brightness and Coma Diameter
--------------------
Comet 146P/Shoemaker-LINEAR (P=8.08a), which passed perihelion on Aug. 5, 2024 in the solar distance of 1.42 AU, became 1.5 mag brighter than predicted. For a rouqh analysis only 21 CCD observations from 6 observers can be used. These hint towards a brightness development according to the rough parameters
m0 = 7.5 mag / n = 18,
yielding a maximum brightness of 14.8 mag in mid-August 2024. The diameter of the diffuse (DC 3) coma peaked at 0.8' (45,000 km). No tail was reported.
Total Brightness and Coma Diameter
--------------------
Comet 154P/Brewington (P=10.51a) passed perihelion in the solar distance of 1.55 AU on June 13, 2024. Until end of year it will move from Aries into the northwestern part of Leo, thereby continually fading.
Although the comet was well observable after perihelion not even 20 observations could be used for a rough analysis, which show a time-dependent brightness development (applying |t-T| instead of log r) according to the rough parameters
m0 = 10.5 mag / nt = 0.04
The comet peaked at 12.0 mag around the time of perihelion. At the end of September the comet had already faded to 16.5 mag. Between mid-June and early October the diameter of the diffuse (DC 3) coma shrank from 1.8' (175,000 km) to 0.8' (80,000 km). A tail was not reported.
Total Brightness and Coma Diameter
--------------------
Comet 207P/NEAT (P=7.65a), which approached Earth to within 0.22 AU on Mar. 5, 2024, was observed between the opening of the year and the start of April 2024. Based on 48 CCD observations by 11 observers the brightness development can be well represented by the parameters
m0 = 17.0 mag / n = 2,
resulting in a maximum brightness of 13.8 mag at the beginning of March 2024. The apparent coma diameter measured 0.4' at the start of the apparition, reached a maximum of 1.1' at the end of February 2024 and shrank to 0.8' by the end of the apparition. In consequence the absolute coma diameter measured only 8,000 km at the start of the apparition, but it quickly increased to 18,000 km afterwards (this value remained constant until the end of the apparition). The coma was moderately condensed (DC 4).
Total Brightness and Coma Diameter
--------------------
Based on only 26 CCD observations by 10 observers comet 226P/Pigott-LINEAR-Kowalski (P=7.31a) reached a maximum brightness of about 15.0 mag in mid-January 2024, thereby showing a maximum coma diameter of 0.8'. The brightness estimates cannot be represented by a standard formula, but indicate a further increase in activity until at least 70 days after perihelion, which means that the apparent brightness changed only slightly after perihelion. The comet will be too close to the Sun for further observations in the coming months.
--------------------
Comet 227P/CATALINA-LINEAR (P=6.37a) passed perihelion at the solar distance of 1.62 AU on Mar. 8, 2024. It reached a maximum brightness of 15.0 mag at the end of February 2024, as 32 CCD observations from 11 observers show. The brightness parameters can only be determined with greater uncertainty, as the variance in the solar distance was very small. Yet the observations hint towards a different brightness development pre- and post-perihelion. The most plausible values are
pre-perihelion: m0 ≈ 2.0m / n ≈ 25.
post-perihelion: m0 ≈ 11.0m / n ≈ 8.
The diameter of the coma increased only from 0.3' (10,000 km) at the beginning of the apparition to 0.6' (25,000 km) at the time of perihelion, but it appears to have been noticeably condensed. A constantly SE-oriented tail of up to 1' (100,000 km) length was observed around perihelion.
Total Brightness and Coma Diameter
--------------------
Comet 473P/NEAT (P=22.50a), which passed perihelion at a solar distance of 1.40 AU on Feb. 26, 2024, reached magnitude 12.5 at the end of February 2024! However, only 17 observations from 6 observers can be used for a very rough analysis. Despite this tiny sample, a different brightness development pre- and post-perihelion seems to be significant. The observations can be represented with the following parameters:
pre-perihelion: m0 ≈ 4.0m / n ≈ 20
post-perihelion: m0 ≈ 8.5m / n ≈ 8
The coma diameter was about 2-3'. A tail was not reported.
--------------------
Comet P/2011 NO1 (Elenin) was rediscovered on Nov. 18, 2023, but was initially confused to be a minor planet, for which was given the designation 2023 WM26. Maik Meyer was the first to recognize that this comet had indeed been rediscovered, thus it later got the permanent designation 479P/Elenin. On Dec. 23 the comet exhibited a highly condensed, 5" coma with a total magnitude of 19.5. The comet will pass perihelion on May 5, 2024 at a distance of 1.24 AU, expected to reach magnitude 14 (CBET 5340). It should be brighter than 16 mag between March and June. During this period, it will pass through the constellations Canis Minor, Monoceros and Hydra (south of Corvus). From Central European locations it can be seen in the evening sky until the beginning of May.
The published observations of this comet are very inconsistent, showing a dichotomy in the brightness estimates. However, by reducing the number of observations of one observer (disproportionately represented) it is possible to get rather robust results. Thus the analysis is based on 37 observations (mostly by CCD) by 17 observers. Their brightness estimates can be roughly represented by the brightness parameters
m0 = 11.0 mag / n = 6,
indicating a peak brightness of 11.5 mag at the start of May 2024 (around perihelion date). During the apparition the coma diameter increased from 0.6' (17,000 km) to 1.3' (35,000 km), whereby the coma is moderately condensed (DC 3). A tail has not been observed. In mid-August the comet had faded below magnitude 16.
Total Brightness and Coma Diameter
Andreas Kammerer
