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Comet C/2024 B1 (Lemmon)

Above the horizon.  Rise: 17:08 | Tran: 23:20 | Set: 5:37
Alt: 40.88°   Az: 170.35°   Direction: South-South-West

Comet C/2024 B1 (Lemmon) is in the constellation of Ophiuchus, at a distance of 401,615,829.0 kilometers from Earth. The current Right Ascension is 16h 29m 24s and the Declination is +02° 44’ 19” (apparent coordinates). The latest observed magnitude of comet C/2024 B1 (Lemmon) is 18.4 (data provided by COBS).

Finder Charts

The sky charts below show, at different resolutions, the position of comet C/2024 B1 (Lemmon) in the sky. Click on each chart to access the interactive star map tool.

Star map showing the position of comet C/2024 B1 (Lemmon) in the constellation of Ophiuchus on F, d Y. Field of view: 50x30 degrees. View interactive star map.
Star map showing the position of comet C/2024 B1 (Lemmon) in the constellation of Ophiuchus on F, d Y. Field of view: 15x9 degrees. View in interactive star map.

The following map uses photographic imagery from the Digitized Sky Survey (DSS) to realistically visualize the precise position of comet C/2024 B1 (Lemmon) against the stars in the background. The horizontal size of the map measures 60 arcminutes. Click on the image to access a more detailed full-screen view.

C/2024 B1 (Lemmon)
RA: 16h 28m 07s
Dec: +02° 47’ 37”
Simplified high-resolution deep sky chart showing the current position of comet C/2024 B1 (Lemmon). Field of view: 60 x 40 arcminutes. Go to the dedicated page

Equatorial Coordinates

Apparent

16h 29m 24s
+02° 44’ 19”
23h 30m 49s
16h 00m 14s

J2000

16h 28m 07s
+02° 47’ 37”

Additional Information

Ophiuchus
18.4
0.4'
n/a
2025-06-16
20.26

The observed values of Magnitude, Coma Diameter and Tail Length are derived from the most recent observation recorded at the Comet Observers Database. The value of Predicted Magnitude comes from the JPL Horizons ephemerides service and, in the case of comets, might be inaccurate given the highly dynamic and unpredictable behavior of these objects. When available, please refer to the Observed Magnitude value and consider the Predicted Magnitude as a directional indication. We acknowledge with thanks the comet observations from the COBS Comet Observation Database contributed by observers worldwide and used in this table to report recent comet observations.

Rise and Set Times

The following table lists today's rise, transit and set times of comet C/2024 B1 (Lemmon) from Greenwich, UK (all times relative to the local timezone Europe/London):

Azimuth: 87.2°
Max altitude: 41.3°
Azimuth: 272.9°

If you need to access this information frequently for your observations, you can create a simple customized Quick Access page, so that you can easily bookmark it in your browser favorites or add a shortcut to your mobile phones' home screen.

Distance from Earth

The distance of comet C/2024 B1 (Lemmon) from Earth is currently 401,615,829.0 kilometers, equivalent to 2.6846359986 Astronomical Units. Light takes 22m 19.646s to travel from comet C/2024 B1 (Lemmon) and arrive to us.

401,615,829.0
2.6846359986
22m 19.646s

The following graph shows the distance of comet C/2024 B1 (Lemmon) from Earth as a function of time. In the chart the distance is measured in Astronomical Units and the data is sampled with an interval of 1 day.

Chart of the distance of comet C/2024 B1 (Lemmon) from Earth in Astronomical Units (au)
Note: The values in this chart may not be entirely accurate around the time of closest approach for objects passing very close to Earth at high speed (e.g., Near-Earth Objects).

The value of the distance of C/2024 B1 (Lemmon) from Earth is also available as a real time updated value in the live position tracker.

Closest Approach to Earth

In the period between January 1, 2000 and December 31, 2099, the closest approach of comet C/2024 B1 (Lemmon) to Earth happened on Tuesday 15 October 2024 at a distance of 1.988227 Astronomical Units, or 297,434,582 kilometers:

Tuesday 15 October 2024
297,434,582
1.988227

Note: the values for the closest approach are computed with a sampling interval of 1 day.

Light Curve

The following chart shows the light curve of comet C/2024 B1 (Lemmon), i.e., its apparent magnitude as a function of time. The curve is calculated using the latest ephemerides provided by JPL Horizons. The magnitude data is sampled with the interval of 2 days. Because of this sampling, inaccuracies may occur for objects that have large variations of brightness over a few days. For comets, large discrepancies can arise between the calculated brightness and the observations due to their highly dynamic, and not always precisely predictable, behavior.

Chart of the magnitude of comet C/2024 B1 (Lemmon) as a function of time

Orbital Elements

The following table lists the orbital elements of comet C/2024 B1 (Lemmon) at epoch December, 28 2023 00:00 UTC (JD: 2460307.5). Source: JPL Small-Body Database

Element Symbol Value
Orbit eccentricity e 1.00102584
Orbit inclination i 70.88192176°
Perihelion distance q 1.63321843 AU
244,326,000 km
Aphelion distance Q n.a.
Semi-major axis a n.a.
Orbital period period n.a.
Date of perihelion transit Tp October 7, 2024
2,460,591.2021 JD
Argument of perihelion peri 66.22067742265°
Longitude of the ascending node node 79.195561535476°
Mean anomaly M -0.0044016914812755°
Mean motion n 0.00001552°/day

Orbit Visualization

The following chart is a 3D animated visualization of the orbit of comet C/2024 B1 (Lemmon) relative to the other major objects in the Solar System. You can access more advanced features using our 3D Solar System Viewer.

15 Days Ephemeris

The following table lists the ephemerides of comet C/2024 B1 (Lemmon) computed for the past and next 7 days, with a 24 hours interval. Apparent celestial coordinates are provided.

Date Right AscensionR.A. DeclinationDec. MagnitudeMag Constellation
Jun 16 2025 16h 38m 23s +04° 27’ 16” 20.04 Hercules
Jun 17 2025 16h 37m 11s +04° 14’ 23” 20.07 Hercules
Jun 18 2025 16h 36m 00s +04° 01’ 27” 20.09 Hercules
Jun 19 2025 16h 34m 50s +03° 48’ 28” 20.12 Hercules
Jun 20 2025 16h 33m 41s +03° 35’ 28” 20.15 Ophiuchus
Jun 21 2025 16h 32m 34s +03° 22’ 25” 20.18 Ophiuchus
Jun 22 2025 16h 31m 27s +03° 09’ 20” 20.21 Ophiuchus
Jun 23 2025 16h 30m 22s +02° 56’ 15” 20.23 Ophiuchus
Jun 24 2025 16h 29m 18s +02° 43’ 09” 20.26 Ophiuchus
Jun 25 2025 16h 28m 16s +02° 30’ 01” 20.29 Ophiuchus
Jun 26 2025 16h 27m 15s +02° 16’ 54” 20.32 Ophiuchus
Jun 27 2025 16h 26m 15s +02° 03’ 46” 20.35 Ophiuchus
Jun 28 2025 16h 25m 17s +01° 50’ 38” 20.38 Ophiuchus
Jun 29 2025 16h 24m 20s +01° 37’ 30” 20.41 Ophiuchus

Additional Resources on TheSkyLive