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Comets » 

Comet 2I/Borisov (C/2019 Q4)

Below the horizon.  Never rises today
Alt: -25.77°   Az: 211.41°   Direction: South-South-West

Comet 2I/Borisov (C/2019 Q4) is in the constellation of Ara, at a distance of 5,763,060,145.0 kilometers from Earth. The current Right Ascension is 18h 06m 29s and the Declination is -54° 58’ 07” (apparent coordinates). The predicted magnitude of Comet 2I/Borisov (C/2019 Q4) is 28.90 (data provided by JPL Horizons).

Finder Charts

Map showing Comet 2I/Borisov (C/2019 Q4) in Ara on May, 28 2025. Field of view: 50x30 degrees
View interactive star map
Sky map showing Comet 2I/Borisov (C/2019 Q4) in Ara on May, 28 2025. Field of view: 15x9 degrees. View in interactive sky chart

High precision deep sky finder chart, 60 arcmin wide, showing where Comet 2I/Borisov (C/2019 Q4) is right now. Click on the image to see a more detailed fullscreen tracker view.

2I/Borisov (C/2019 Q4)
RA: 18h 04m 22s
Dec: -54° 58’ 19”
Deep sky finder chart for Comet 2I/Borisov (C/2019 Q4). Field of view: 60x40 arcmins. View in deep sky object tracker

Also check out Where is Comet 2I/Borisov (C/2019 Q4)?, a page that provides all the information needed to find Comet 2I/Borisov (C/2019 Q4) in the sky and additional links to sky charts.

Celestial Coordinates

Apparent

18h 06m 29s
-54° 58’ 07”
03h 39m 20s
21h 45m 50s

J2000

18h 04m 22s
-54° 58’ 19”

Additional Information

Ara
n/a
n/a
n/a
n/a
28.90

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

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):

Today Comet 2I/Borisov (C/2019 Q4) is not visible from Greenwich, UK

  • 2I/Borisov (C/2019 Q4) is below the horizon from Greenwich, UK.
  • Given its current magnitude, 2I/Borisov (C/2019 Q4) is visible only through long exposure photography.
  • Go to interactive sky chart

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 5,763,060,145.0 kilometers, equivalent to 38.5236776301 Astronomical Units. Light takes 5h 20m 23.499s to travel from Comet 2I/Borisov (C/2019 Q4) and arrive to us.

5,763,060,145.0
38.5236776301
5h 20m 23.499s

The following chart shows the distance of Comet 2I/Borisov (C/2019 Q4) from Earth as a function of time. In the chart the distance data is measured in Astronomical Units and sampled with an interval of 1 day.

Chart of the distance of Comet 2I/Borisov (C/2019 Q4) from Earth in Astronomical Units (au)

The value of the reported distance might be somewhat inaccurate around the times of closest approach for objects passing extremely close to Earth. 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 and Data Tracker.

Closest Approach

Between 1 January 2000 and 31 December 2099, the closest approach of Comet 2I/Borisov (C/2019 Q4) to Earth happens on Sat Dec 28 2019 at a distance of 1.936739 Astronomical Units, or 289,732,033 kilometers:

Sat Dec 28 2019
289,732,033
1.936739

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

Light Curve

The following chart is the predicted light curve (visual magnitude as a function of time) of Comet 2I/Borisov (C/2019 Q4), according to the most recent ephemerides data. Magnitude data is sampled with a 2 days interval and there might be inaccuracies for objects changing brightness very rapidly during the course of a few days. For comets there could be large discrepancies between the observed and predicted brightness because of their highly dynamic behaviour.

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 04 January 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 2019-Dec-08 13:16:05
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
2h1>Orbit Visualization
Orbit Diagram of Comet 2I/Borisov (C/2019 Q4)
View Comet 2I/Borisov (C/2019 Q4) in the 3D Solar System Simulator

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
2025 May 21 18h 07m 33s -54° 55’ 53” 28.89 Ara
2025 May 22 18h 07m 24s -54° 56’ 15” 28.89 Ara
2025 May 23 18h 07m 16s -54° 56’ 34” 28.90 Ara
2025 May 24 18h 07m 07s -54° 56’ 53” 28.90 Ara
2025 May 25 18h 06m 58s -54° 57’ 13” 28.90 Ara
2025 May 26 18h 06m 49s -54° 57’ 30” 28.90 Ara
2025 May 27 18h 06m 40s -54° 57’ 47” 28.90 Ara
2025 May 28 18h 06m 31s -54° 58’ 04” 28.90 Ara
2025 May 29 18h 06m 22s -54° 58’ 19” 28.91 Ara
2025 May 30 18h 06m 13s -54° 58’ 33” 28.91 Ara
2025 May 31 18h 06m 04s -54° 58’ 48” 28.91 Ara
2025 Jun 01 18h 05m 55s -54° 59’ 00” 28.91 Ara
2025 Jun 02 18h 05m 45s -54° 59’ 12” 28.91 Ara
2025 Jun 03 18h 05m 36s -54° 59’ 24” 28.91 Ara

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