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Comet C/2017 O1 (ASASSN1)

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Comet C/2017 O1 (ASASSN1) Position

Comet C/2017 O1 (ASASSN1) is currently in the constellation of Coma. The current Right Ascension is 12h 40m 50s and the Declination is +16° 13’ 42”.

12h 40m 50s
+16° 13’ 42”

Simplified sky chart showing where Comet C/2017 O1 (ASASSN1) is right now in the sky with respect to the brightest stars and constellations (see full screen Online Planetarium)

Map showing Comet C/2017 O1 (ASASSN1) in Coma on April, 07 2020
Field of view: 60x30 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 showing where Comet C/2017 O1 (ASASSN1) is right now (view fullscreen)

C/2017 O1 (ASASSN1)
RA: 12h 40m 50s
Dec: +16° 13’ 42”
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

The distance of Comet C/2017 O1 (ASASSN1) from Earth is currently 1,209,184,942 kilometers, equivalent to 8.082902 Astronomical Units. Light takes 1 hours, 7 minutes and 13.4068 seconds to travel from Comet C/2017 O1 (ASASSN1) and arrive to us.

1 hours, 7 minutes and 13.4068 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 0.71974650 Astronomical Units, or 107,672,544 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 24.67.


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: 73.8°
Max altitude: 54.8°
Azimuth: 286.2°
Comet C/2017 O1 (ASASSN1) is above the horizon from Greenwich, United Kingdom

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 0.99642390
Orbit inclination i 39.84839798°
Perihelion distance q 1.49868671 AU
224,200,342 km
Aphelion distance Q 836.66966386 AU
125,164,000,444 km
Semi-major axis a 419.08417529 AU
62,694,100,393 km
Orbital period period 8,579.4600 years
3,133,648.7869 days
Date of perihelion transit Tp 2017-Oct-14 18:50:41
2,458,041.2852 JD
Next perihelion transit 10597-Jun-04 13:43
5,591,690.0721 JD
Argument of perihelion peri 20.907869077143°
Longitude of the ascending node node 25.809478842856°
Mean anomaly M 359.99979491201°
Mean motion n 0.00011488°/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 Mar 31 12h 43m 54s +16° 04’ 36” 24.63 Coma
2020 Apr 01 12h 43m 27s +16° 06’ 01” 24.64 Coma
2020 Apr 02 12h 43m 02s +16° 07’ 23” 24.64 Coma
2020 Apr 03 12h 42m 38s +16° 08’ 41” 24.65 Coma
2020 Apr 04 12h 42m 11s +16° 09’ 57” 24.66 Coma
2020 Apr 05 12h 41m 47s +16° 11’ 09” 24.66 Coma
2020 Apr 06 12h 41m 21s +16° 12’ 19” 24.67 Coma
2020 Apr 07 12h 40m 56s +16° 13’ 24” 24.67 Coma
2020 Apr 08 12h 40m 32s +16° 14’ 27” 24.68 Coma
2020 Apr 09 12h 40m 08s +16° 15’ 27” 24.68 Coma
2020 Apr 10 12h 39m 42s +16° 16’ 23” 24.69 Coma
2020 Apr 11 12h 39m 19s +16° 17’ 16” 24.70 Coma
2020 Apr 12 12h 38m 54s +16° 18’ 05” 24.70 Coma
2020 Apr 13 12h 38m 30s +16° 18’ 51” 24.71 Coma