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🌎  Observing from: Greenwich, United Kingdom [change]

Comet 117P/Helin-Roman-Alu 1

Comet 117P/Helin-Roman-Alu 1 is currently in the constellation of Capricornus. The current Right Ascension of Comet 117P/Helin-Roman-Alu 1 is 21h 48m 07s and the Declination is -20° 20’ 17” (topocentric coordinates computed for the selected location: Greenwich, United Kingdom [change]). The current estimated magnitude of Comet 117P/Helin-Roman-Alu 1 is 16.30 (JPL).

Summary of key facts about Comet 117P/Helin-Roman-Alu 1 [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]:

21h 48m 07s
-20° 20’ 17”

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 117P/Helin-Roman-Alu 1 available on TheSkyLive:

Available Resources

Comet 117P/Helin-Roman-Alu 1 Position and Finder Charts

Below we provide Comet 117P/Helin-Roman-Alu 1 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 117P/Helin-Roman-Alu 1 in Capricornus on February, 05 2023
Field of view: 50x30 degrees
View fullscreen
Map showing Comet 117P/Helin-Roman-Alu 1 in Capricornus on February, 05 2023
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 117P/Helin-Roman-Alu 1 is right now. Click on the image to see a more detailed fullscreen tracker view.

117P/Helin-Roman-Alu 1
RA: 21h 48m 07s
Dec: -20° 20’ 17”
Deep sky finder chart for Comet 117P/Helin-Roman-Alu 1
Field of view: 60x40 arcmins
View fullscreen

Also check out Where is Comet 117P/Helin-Roman-Alu 1?, a page that provides all the information needed to find Comet 117P/Helin-Roman-Alu 1 in the sky and additional links to sky charts.

Comet 117P/Helin-Roman-Alu 1 Distance from Earth

The distance of Comet 117P/Helin-Roman-Alu 1 from Earth is currently 625,517,968 kilometers, equivalent to 4.181329 Astronomical Units. Light takes 34 minutes and 46.5034 seconds to travel from Comet 117P/Helin-Roman-Alu 1 and arrive to us.

34 minutes and 46.5034 seconds

The following chart shows the distance of Comet 117P/Helin-Roman-Alu 1 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 117P/Helin-Roman-Alu 1 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 117P/Helin-Roman-Alu 1 from Earth is also available as a real time updated value in the Live Position and Data Tracker.

Closest approach of Comet 117P/Helin-Roman-Alu 1 to Earth

Between January 2013 and December 2100, the closest approach of Comet 117P/Helin-Roman-Alu 1 to Earth happens on Sun Jul 3 2022 at a distance of 2.030851 Astronomical Units, or 303,811,017 kilometers:

Sun Jul 3 2022

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

Comet 117P/Helin-Roman-Alu 1 brightness

The current visual magnitude of Comet 117P/Helin-Roman-Alu 1 is 16.30.


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 117P/Helin-Roman-Alu 1, 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 117P/Helin-Roman-Alu 1 between January 2013 and December 2100

Comet 117P/Helin-Roman-Alu 1 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 117P/Helin-Roman-Alu 1 rise, transit and set times from Greenwich, United Kingdom [change] are the following (all times relative to the local timezone Europe/London):

Azimuth: 110.3°
Max altitude: 18.2°
Azimuth: 249.7°

The rise and set times are defined as the time at which the upper limb of Comet 117P/Helin-Roman-Alu 1 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 117P/Helin-Roman-Alu 1 Orbital Elements

The following table lists the orbital elements of Comet 117P/Helin-Roman-Alu 1 at epoch 26 February 2017 00:00 UTC (JD: 2457811.5). Source: JPL Small-Body Database

Element Symbol Value
Orbit eccentricity e 0.25437763
Orbit inclination i 8.70068183°
Perihelion distance q 3.05209567 AU
456,587,015 km
Aphelion distance Q 5.13461062 AU
768,126,816 km
Semi-major axis a 4.09335314 AU
612,356,916 km
Orbital period period 8.2818 years
3,024.9434 days
Date of perihelion transit Tp 2014-Mar-26 18:07:22
2,456,743.2551 JD
Next perihelion transit 2022-Jul-07 16:45
2,459,768.1985 JD
Argument of perihelion peri 222.51149215237°
Longitude of the ascending node node 58.874006259934°
Mean anomaly M 127.13234976963°
Mean motion n 0.11901049°/day

Visualization of Comet 117P/Helin-Roman-Alu 1 Orbit

This 3d orbit diagram is a feature of our 3D Solar System Simulator and shows the orbit of Comet 117P/Helin-Roman-Alu 1 with respect of the Sun and the orbits of the major planets. The position of Comet 117P/Helin-Roman-Alu 1 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 117P/Helin-Roman-Alu 1
View Comet 117P/Helin-Roman-Alu 1 in the 3D Solar System Simulator

Comet 117P/Helin-Roman-Alu 1 15 Days Ephemeris

The following table lists the ephemerides of Comet 117P/Helin-Roman-Alu 1 computed for the past and next 7 days, with a 24 hours interval. Click on each row of the table to locate Comet 117P/Helin-Roman-Alu 1 in our Online Planetarium at the chosen date.

Date Right AscensionR.A. DeclinationDec. MagnitudeMag Constellation
2023 Jan 29 21h 36m 51s -21° 15’ 56” 16.27 Capricornus
2023 Jan 30 21h 38m 25s -21° 08’ 24” 16.27 Capricornus
2023 Jan 31 21h 39m 57s -21° 00’ 50” 16.28 Capricornus
2023 Feb 01 21h 41m 30s -20° 53’ 13” 16.28 Capricornus
2023 Feb 02 21h 43m 01s -20° 45’ 37” 16.29 Capricornus
2023 Feb 03 21h 44m 35s -20° 37’ 58” 16.29 Capricornus
2023 Feb 04 21h 46m 06s -20° 30’ 17” 16.30 Capricornus
2023 Feb 05 21h 47m 39s -20° 22’ 36” 16.30 Capricornus
2023 Feb 06 21h 49m 10s -20° 14’ 53” 16.31 Capricornus
2023 Feb 07 21h 50m 41s -20° 07’ 10” 16.31 Capricornus
2023 Feb 08 21h 52m 14s -19° 59’ 26” 16.31 Capricornus
2023 Feb 09 21h 53m 44s -19° 51’ 39” 16.32 Capricornus
2023 Feb 10 21h 55m 15s -19° 43’ 53” 16.32 Capricornus
2023 Feb 11 21h 56m 48s -19° 36’ 05” 16.33 Capricornus