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🌎 Location: Greenwich, United Kingdom [change]

Comet C/2017 K4 (ATLAS)

Comet C/2017 K4 (ATLAS) is currently in the constellation of Auriga. The current Right Ascension of Comet C/2017 K4 (ATLAS) is 04h 58m 21s and the Declination is +36° 04’ 50” (topocentric coordinates computed for the selected location: Greenwich, United Kingdom [change]). The current estimated magnitude of Comet C/2017 K4 (ATLAS) is 27.58 (JPL).

Summary of key facts about Comet C/2017 K4 (ATLAS) [tip: you can also create a Quick Access page for this data if you access it frequently and would like to have a simpler view]:

04h 58m 21s
+36° 04’ 50”
  • C/2017 K4 (ATLAS) is above the horizon from Greenwich, United Kingdom [change].
  • It is visible looking in the East-North-East direction at an altitude of 27° above the horizon.
  • Given its current magnitude, C/2017 K4 (ATLAS) is visible only through long exposure photography.
  • See also C/2017 K4 (ATLAS) rise and set times.
  • 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.

Additional information about Comet C/2017 K4 (ATLAS) available on TheSkyLive:

Available Resources

Comet C/2017 K4 (ATLAS) Position and Finder Charts

Below we provide Comet C/2017 K4 (ATLAS) finder charts showing where the object is right now in the sky with respect to the brightest stars. The first finder chart has a field of view of 50 degrees, while the second one has a field of view of 10 degrees. Click on each finder chart to access a full screen interactive Online Planetarium.

Map showing Comet C/2017 K4 (ATLAS) in Auriga on October, 31 2020
Field of view: 50x30 degrees
View fullscreen
Map showing Comet C/2017 K4 (ATLAS) in Auriga on October, 31 2020
Field of view: 10x6 degrees
View fullscreen
 = visible to the naked eye
 = binocular, brighter than 10th magnitude
= current altitude ≥ 30°   = current altitude < 30°   = below the horizon
Location: Greenwich, United Kingdom [change]

Higher precision deep sky finder chart, 60 arcmin wide, showing where Comet C/2017 K4 (ATLAS) is right now. Click on the image to see a more detailed fullscreen tracker view.

C/2017 K4 (ATLAS)
RA: 04h 58m 21s
Dec: +36° 04’ 50”
Deep sky finder chart for Comet C/2017 K4 (ATLAS)
Field of view: 60x40 arcmins
View fullscreen

Also check out Where is Comet C/2017 K4 (ATLAS)?, a page that provides all the information needed to find Comet C/2017 K4 (ATLAS) in the sky and additional links to sky charts.

Comet C/2017 K4 (ATLAS) Distance from Earth

The distance of Comet C/2017 K4 (ATLAS) from Earth is currently 1,193,215,548 kilometers, equivalent to 7.976153 Astronomical Units. Light takes 1 hours, 6 minutes and 20.1386 seconds to travel from Comet C/2017 K4 (ATLAS) and arrive to us.

1 hours, 6 minutes and 20.1386 seconds

The following chart shows the distance of Comet C/2017 K4 (ATLAS) 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.

Distance of Comet C/2017 K4 (ATLAS) from Earth between January 2013 and December 2100

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 C/2017 K4 (ATLAS) from Earth is also available as a real time updated value in the Live Position and Data Tracker.

Closest approach of Comet C/2017 K4 (ATLAS) to Earth

Between January 2013 and December 2100, the closest approach of Comet C/2017 K4 (ATLAS) to Earth happens on Mon Jul 3 2017 at a distance of 2.310735 Astronomical Units, or 345,681,065 kilometers:

Mon Jul 3 2017

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

Comet C/2017 K4 (ATLAS) brightness

The current visual magnitude of Comet C/2017 K4 (ATLAS) is 27.58.


The observed magnitude and coma diameter values are derived from the Comet Observers Database by averaging the values reported in recent observations (more recent than 4 days), when available. The Estimated Magnitude comes from the JPL Horizons ephemerides service and might be inaccurate given the highly dynamic and unpredictable behavior of comets. When available, please refer to the Observed Magnitude value and consider the Estimated 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.

The following chart is the predicted light curve (visual magnitude as a function of time) of Comet C/2017 K4 (ATLAS), 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.

Predicted magnitude of Comet C/2017 K4 (ATLAS) between January 2013 and December 2100

Comet C/2017 K4 (ATLAS) rise and set times

Location: Greenwich, United Kingdom [change]
Latitude: 51° 28’ 47” N
Longitude: 0° 00’ 00” E
Timezone: Europe/London

Today's Comet C/2017 K4 (ATLAS) rise, transit and set times from Greenwich, United Kingdom [change] are the following (all times relative to the local timezone Europe/London):

Azimuth: 53.9°
Max altitude: 74.6°
Azimuth: 306.1°

The rise and set times are defined as the time at which the upper limb of Comet C/2017 K4 (ATLAS) touches the horizon, considering the effect of the atmospheric refraction. As the atmospheric conditions cannot be modeled precisely the times reported here should be considered correct with an approximation of few minutes.

Comet C/2017 K4 (ATLAS) Orbital Elements

The following table lists the orbital elements of Comet C/2017 K4 (ATLAS) at epoch 27 March 2018 00:00 UTC (JD: 2458205.5). Source: JPL Small-Body Database

Element Symbol Value
Orbit eccentricity e 0.90585450
Orbit inclination i 16.67870561°
Perihelion distance q 2.64808502 AU
396,147,881 km
Aphelion distance Q 53.60707258 AU
8,019,503,929 km
Semi-major axis a 28.12757880 AU
4,207,825,905 km
Orbital period period 149.1800 years
54,487.5088 days
Date of perihelion transit Tp 2018-Jan-08 01:00:52
2,458,126.5423 JD
Next perihelion transit 2167-Mar-15 13:13
2,512,614.0510 JD
Argument of perihelion peri 15.111910899548°
Longitude of the ascending node node 298.89726993063°
Mean anomaly M 0.52167521741479°
Mean motion n 0.00660702°/day

Visualization of Comet C/2017 K4 (ATLAS) Orbit

This 3d orbit diagram is a feature of our 3D Solar System Simulator and shows the orbit of Comet C/2017 K4 (ATLAS) with respect of the Sun and the orbits of the major planets. The position of Comet C/2017 K4 (ATLAS) and the planets along their orbits in this diagram accurately represents the current configuration of the objects in the Solar System. This is an experimental feature and it requires a WebGL enabled browser. Please provide us feedback!

Orbit Diagram of Comet C/2017 K4 (ATLAS)
View Comet C/2017 K4 (ATLAS) in the 3D Solar System Simulator

Comet C/2017 K4 (ATLAS) 15 Days Ephemeris

The following table lists the ephemerides of Comet C/2017 K4 (ATLAS) computed for the past and next 7 days, with a 24 hours interval. Click on each row of the table to locate Comet C/2017 K4 (ATLAS) in our Online Planetarium at the chosen date.

Date Right AscensionR.A. DeclinationDec. MagnitudeMag Constellation
2020 Oct 24 05h 00m 53s +36° 02’ 48” 27.55 Auriga
2020 Oct 25 05h 00m 35s +36° 03’ 11” 27.55 Auriga
2020 Oct 26 05h 00m 17s +36° 03’ 30” 27.56 Auriga
2020 Oct 27 04h 59m 58s +36° 03’ 50” 27.56 Auriga
2020 Oct 28 04h 59m 39s +36° 04’ 05” 27.56 Auriga
2020 Oct 29 04h 59m 20s +36° 04’ 20” 27.57 Auriga
2020 Oct 30 04h 58m 59s +36° 04’ 32” 27.57 Auriga
2020 Oct 31 04h 58m 39s +36° 04’ 44” 27.58 Auriga
2020 Nov 01 04h 58m 18s +36° 04’ 51” 27.58 Auriga
2020 Nov 02 04h 57m 56s +36° 04’ 58” 27.59 Auriga
2020 Nov 03 04h 57m 34s +36° 05’ 02” 27.59 Auriga
2020 Nov 04 04h 57m 12s +36° 05’ 03” 27.60 Auriga
2020 Nov 05 04h 56m 49s +36° 05’ 03” 27.60 Auriga
2020 Nov 06 04h 56m 26s +36° 05’ 00” 27.61 Auriga