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Comets » 

Comet 2I/Borisov (C/2019 Q4)

Below the horizon.  Never rises today
Alt: -24.08°   Az: 208.50°   Direction: South-South-West

Comet 2I/Borisov (C/2019 Q4) is in the constellation of Ara, at a distance of 5,859,450,327.0 kilometers from Earth. The current Right Ascension is 18h 00m 37s and the Declination is -54° 58’ 25” (apparent coordinates). The estimated magnitude of comet 2I/Borisov (C/2019 Q4), computed using JPL Horizons's data, is 28.98).

Finder Charts

The sky charts below show, at different resolutions, the position of comet 2I/Borisov (C/2019 Q4) in the sky. Click on each chart to access the interactive star map tool.

Star map showing the position of comet 2I/Borisov (C/2019 Q4) in the constellation of Ara on F, d Y. Field of view: 50x30 degrees. View interactive star map.
Star map showing the position of comet 2I/Borisov (C/2019 Q4) in the constellation of Ara 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 2I/Borisov (C/2019 Q4) 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.

2I/Borisov (C/2019 Q4)
RA: 17h 58m 30s
Dec: -54° 58’ 24”
Simplified high-resolution deep sky chart showing the current position of comet 2I/Borisov (C/2019 Q4). Field of view: 60 x 40 arcminutes. Go to the dedicated page

Equatorial Coordinates

Apparent

18h 00m 37s
-54° 58’ 25”
03h 17m 31s
21h 18m 08s

J2000

17h 58m 30s
-54° 58’ 24”

Additional Information

Ara
n/a
n/a
n/a
n/a
28.98

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 2I/Borisov (C/2019 Q4) from Greenwich, UK (all times relative to the local timezone Europe/London):

Greenwich, UKToday comet 2I/Borisov (C/2019 Q4) is not visible from

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 2I/Borisov (C/2019 Q4) from Earth is currently 5,859,450,327.0 kilometers, equivalent to 39.1680061994 Astronomical Units. Light takes 5h 25m 45.022s to travel from comet 2I/Borisov (C/2019 Q4) and arrive to us.

5,859,450,327.0
39.1680061994
5h 25m 45.022s

The following graph shows the distance of comet 2I/Borisov (C/2019 Q4) 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 2I/Borisov (C/2019 Q4) 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 2I/Borisov (C/2019 Q4) 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 2I/Borisov (C/2019 Q4) to Earth happened on Saturday 28 December 2019 at a distance of 1.936739 Astronomical Units, or 289,732,033 kilometers:

Saturday 28 December 2019
289,732,033
1.936739

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 2I/Borisov (C/2019 Q4), 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 2I/Borisov (C/2019 Q4) as a function of time

Orbital Elements

The following table lists the orbital elements of comet 2I/Borisov (C/2019 Q4) at epoch January, 04 2020 00:00 UTC (JD: 2458853.5). Source: JPL Small-Body Database

Element Symbol Value
Orbit eccentricity e 3.35647578
Orbit inclination i 44.05264248°
Perihelion distance q 2.00652088 AU
300,171,252 km
Aphelion distance Q n.a.
Semi-major axis a n.a.
Orbital period period n.a.
Date of perihelion transit Tp December 8, 2019
2,458,826.0528 JD
Argument of perihelion peri 209.12368643781°
Longitude of the ascending node node 308.14772922699°
Mean anomaly M 34.429470307218°
Mean motion n 1.25439126°/day

Orbit Visualization

The following chart is a 3D animated visualization of the orbit of comet 2I/Borisov (C/2019 Q4) 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 2I/Borisov (C/2019 Q4) 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 27 2025 18h 01m 44s -54° 59’ 50” 28.96 Ara
Jun 28 2025 18h 01m 35s -54° 59’ 41” 28.96 Ara
Jun 29 2025 18h 01m 25s -54° 59’ 30” 28.96 Ara
Jun 30 2025 18h 01m 16s -54° 59’ 19” 28.97 Ara
Jul 01 2025 18h 01m 06s -54° 59’ 08” 28.97 Ara
Jul 02 2025 18h 00m 57s -54° 58’ 55” 28.97 Ara
Jul 03 2025 18h 00m 47s -54° 58’ 41” 28.97 Ara
Jul 04 2025 18h 00m 38s -54° 58’ 27” 28.98 Ara
Jul 05 2025 18h 00m 28s -54° 58’ 12” 28.98 Ara
Jul 06 2025 18h 00m 19s -54° 57’ 55” 28.98 Ara
Jul 07 2025 18h 00m 10s -54° 57’ 39” 28.98 Ara
Jul 08 2025 18h 00m 00s -54° 57’ 22” 28.98 Ara
Jul 09 2025 17h 59m 50s -54° 57’ 03” 28.99 Ara
Jul 10 2025 17h 59m 41s -54° 56’ 45” 28.99 Ara

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