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Comet 17P/Holmes

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Comet 17P/Holmes Position

Comet 17P/Holmes is currently in the constellation of Corona Australis. The current Right Ascension is 18h 34m 32s and the Declination is -42° 28’ 03”.

18h 34m 32s
-42° 28’ 03”

Simplified sky chart showing where Comet 17P/Holmes is right now in the sky with respect to the brightest stars and constellations (see full screen Online Planetarium)

Map showing Comet 17P/Holmes in Corona Australis on March, 29 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 17P/Holmes is right now (view fullscreen)

RA: 18h 34m 32s
Dec: -42° 28’ 03”
Deep sky finder chart for Comet 17P/Holmes
Field of view: 60x40 arcmins
View fullscreen

Also check out Where is Comet 17P/Holmes?, a page that provides all the information needed to find Comet 17P/Holmes in the sky and additional links to sky charts.

Comet 17P/Holmes Distance

The distance of Comet 17P/Holmes from Earth is currently 432,208,355 kilometers, equivalent to 2.889134 Astronomical Units. Light takes 24 minutes and 1.6919 seconds to travel from Comet 17P/Holmes and arrive to us.

24 minutes and 1.6919 seconds

The following chart shows the distance of Comet 17P/Holmes 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 17P/Holmes 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 17P/Holmes from Earth is also available as a real time updated value in the Live Position and Data Tracker.

Closest approach of Comet 17P/Holmes to Earth

Between January 2013 and December 2100 the closest approach of Comet 17P/Holmes to Earth happens on Thu Aug 20 2048 at a distance of 1.14521990 Astronomical Units, or 171,322,459 kilometers:

Thu Aug 20 2048

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

Comet 17P/Holmes brightness

The current visual magnitude of Comet 17P/Holmes is 18.56.


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 17P/Holmes, 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 17P/Holmes between January 2013 and December 2100

Comet 17P/Holmes rise and set times

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

Comet 17P/Holmes is currently not visible from Greenwich, United Kingdom [change]

The rise and set times are defined as the time at which the upper limb of Comet 17P/Holmes 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 17P/Holmes Orbital Elements

The following table lists the orbital elements of Comet 17P/Holmes at epoch 02 August 2014 00:00 UTC (JD: 2456872.5). Source: JPL Small-Body Database

Element Symbol Value
Orbit eccentricity e 0.43181344
Orbit inclination i 19.09175525°
Perihelion distance q 2.05661374 AU
307,665,038 km
Aphelion distance Q 5.18260623 AU
775,306,858 km
Semi-major axis a 3.61960999 AU
541,485,948 km
Orbital period period 6.8900 years
2,515.3075 days
Date of perihelion transit Tp 2014-Mar-27 12:18:11
2,456,744.0126 JD
Next perihelion transit 2021-Feb-13 19:41
2,459,259.3202 JD
Argument of perihelion peri 24.515349359396°
Longitude of the ascending node node 326.76479965817°
Mean anomaly M 18.389581859552°
Mean motion n 0.14312365°/day

Visualization of Comet 17P/Holmes Orbit

This 3d orbit diagram is a feature of our 3D Solar System Simulator and shows the orbit of Comet 17P/Holmes with respect of the Sun and the orbits of the major planets. The position of Comet 17P/Holmes 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 17P/Holmes
View Comet 17P/Holmes in the 3D Solar System Simulator

Comet 17P/Holmes 15 Days Ephemeris

The following table lists the ephemerides of Comet 17P/Holmes computed for the past and next 7 days, with a 24 hours interval. Click on each row of the table to locate Comet 17P/Holmes in our Online Planetarium at the chosen date.

Date Right AscensionR.A. DeclinationDec. MagnitudeMag Constellation
2020 Mar 22 18h 25m 59s -42° 02’ 22” 18.72 Corona Australis
2020 Mar 23 18h 27m 11s -42° 05’ 44” 18.70 Corona Australis
2020 Mar 24 18h 28m 21s -42° 09’ 06” 18.68 Corona Australis
2020 Mar 25 18h 29m 30s -42° 12’ 29” 18.66 Corona Australis
2020 Mar 26 18h 30m 38s -42° 15’ 54” 18.63 Corona Australis
2020 Mar 27 18h 31m 45s -42° 19’ 18” 18.61 Corona Australis
2020 Mar 28 18h 32m 52s -42° 22’ 45” 18.59 Corona Australis
2020 Mar 29 18h 33m 57s -42° 26’ 12” 18.57 Corona Australis
2020 Mar 30 18h 35m 03s -42° 29’ 41” 18.55 Corona Australis
2020 Mar 31 18h 36m 06s -42° 33’ 11” 18.53 Corona Australis
2020 Apr 01 18h 37m 09s -42° 36’ 42” 18.50 Corona Australis
2020 Apr 02 18h 38m 11s -42° 40’ 14” 18.48 Corona Australis
2020 Apr 03 18h 39m 11s -42° 43’ 49” 18.46 Corona Australis
2020 Apr 04 18h 40m 12s -42° 47’ 23” 18.44 Corona Australis