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🌎 Location: Greenwich, United Kingdom [change]

Comet C/2017 O1 (ASASSN1)

Comet C/2017 O1 (ASASSN1) is currently in the constellation of Virgo. The current Right Ascension of Comet C/2017 O1 (ASASSN1) is 12h 56m 51s and the Declination is +08° 37’ 39” (topocentric coordinates computed for the selected location: Greenwich, United Kingdom [change]). The current estimated magnitude of Comet C/2017 O1 (ASASSN1) is 25.92 (JPL).

Summary of key facts about Comet C/2017 O1 (ASASSN1) [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]:

12h 56m 51s
+08° 37’ 39”

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Additional information about Comet C/2017 O1 (ASASSN1) available on TheSkyLive:

Available Resources

Comet C/2017 O1 (ASASSN1) Position and Finder Charts

Below we provide Comet C/2017 O1 (ASASSN1) 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 O1 (ASASSN1) in Virgo on October, 25 2020
Field of view: 50x30 degrees
View fullscreen
Map showing Comet C/2017 O1 (ASASSN1) in Virgo on October, 25 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 O1 (ASASSN1) is right now. Click on the image to see a more detailed fullscreen tracker view.

C/2017 O1 (ASASSN1)
RA: 12h 56m 51s
Dec: +08° 37’ 39”
Deep sky finder chart for Comet C/2017 O1 (ASASSN1)
Field of view: 60x40 arcmins
View fullscreen

Also check out Where is Comet C/2017 O1 (ASASSN1)?, a page that provides all the information needed to find Comet C/2017 O1 (ASASSN1) in the sky and additional links to sky charts.

Comet C/2017 O1 (ASASSN1) Distance from Earth

The distance of Comet C/2017 O1 (ASASSN1) from Earth is currently 1,693,900,251 kilometers, equivalent to 11.323024 Astronomical Units. Light takes 1 hours, 34 minutes and 10.2430 seconds to travel from Comet C/2017 O1 (ASASSN1) and arrive to us.

1 hours, 34 minutes and 10.2430 seconds

The following chart shows the distance of Comet C/2017 O1 (ASASSN1) 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 O1 (ASASSN1) 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 O1 (ASASSN1) from Earth is also available as a real time updated value in the Live Position and Data Tracker.

Closest approach of Comet C/2017 O1 (ASASSN1) to Earth

Between January 2013 and December 2100, the closest approach of Comet C/2017 O1 (ASASSN1) to Earth happens on Wed Oct 18 2017 at a distance of 0.719747 Astronomical Units, or 107,672,562 kilometers:

Wed Oct 18 2017

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

Comet C/2017 O1 (ASASSN1) brightness

The current visual magnitude of Comet C/2017 O1 (ASASSN1) is 25.92.


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 O1 (ASASSN1), 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 O1 (ASASSN1) between January 2013 and December 2100

Comet C/2017 O1 (ASASSN1) 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 O1 (ASASSN1) rise, transit and set times from Greenwich, United Kingdom [change] are the following (all times relative to the local timezone Europe/London):

Azimuth: 81.3°
Max altitude: 47.2°
Azimuth: 278.6°

The rise and set times are defined as the time at which the upper limb of Comet C/2017 O1 (ASASSN1) 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 O1 (ASASSN1) Orbital Elements

The following table lists the orbital elements of Comet C/2017 O1 (ASASSN1) at epoch 12 October 2017 00:00 UTC (JD: 2458039.5). Source: JPL Small-Body Database

Element Symbol Value
Orbit eccentricity e 0.99642416
Orbit inclination i 39.84840212°
Perihelion distance q 1.49868675 AU
224,200,347 km
Aphelion distance Q 836.73165089 AU
125,173,273,571 km
Semi-major axis a 419.11516882 AU
62,698,736,959 km
Orbital period period 8,580.4100 years
3,133,996.4186 days
Date of perihelion transit Tp 2017-Oct-14 18:50:40
2,458,041.2852 JD
Next perihelion transit 10598-May-18 04:53
5,592,037.7038 JD
Argument of perihelion peri 20.907861416189°
Longitude of the ascending node node 25.809481066717°
Mean anomaly M 359.99979493653°
Mean motion n 0.00011487°/day

Visualization of Comet C/2017 O1 (ASASSN1) Orbit

This 3d orbit diagram is a feature of our 3D Solar System Simulator and shows the orbit of Comet C/2017 O1 (ASASSN1) with respect of the Sun and the orbits of the major planets. The position of Comet C/2017 O1 (ASASSN1) 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 O1 (ASASSN1)
View Comet C/2017 O1 (ASASSN1) in the 3D Solar System Simulator

Comet C/2017 O1 (ASASSN1) 15 Days Ephemeris

The following table lists the ephemerides of Comet C/2017 O1 (ASASSN1) 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 O1 (ASASSN1) in our Online Planetarium at the chosen date.

Date Right AscensionR.A. DeclinationDec. MagnitudeMag Constellation
2020 Oct 18 12h 54m 11s +08° 55’ 17” 25.90 Virgo
2020 Oct 19 12h 54m 32s +08° 52’ 55” 25.90 Virgo
2020 Oct 20 12h 54m 52s +08° 50’ 35” 25.91 Virgo
2020 Oct 21 12h 55m 13s +08° 48’ 17” 25.91 Virgo
2020 Oct 22 12h 55m 33s +08° 46’ 01” 25.91 Virgo
2020 Oct 23 12h 55m 54s +08° 43’ 48” 25.91 Virgo
2020 Oct 24 12h 56m 13s +08° 41’ 35” 25.92 Virgo
2020 Oct 25 12h 56m 35s +08° 39’ 24” 25.92 Virgo
2020 Oct 26 12h 56m 54s +08° 37’ 15” 25.92 Virgo
2020 Oct 27 12h 57m 15s +08° 35’ 08” 25.92 Virgo
2020 Oct 28 12h 57m 34s +08° 33’ 03” 25.93 Virgo
2020 Oct 29 12h 57m 53s +08° 31’ 00” 25.93 Virgo
2020 Oct 30 12h 58m 14s +08° 28’ 59” 25.93 Virgo
2020 Oct 31 12h 58m 33s +08° 26’ 59” 25.93 Virgo