Comet 123P/West-Hartley
Comet 123P/West-Hartley is in the constellation of
Aries,
at a distance of
Finder Charts
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High precision deep sky finder chart, 60 arcmin wide, showing where Comet 123P/West-Hartley is right now. Click on the image to see a more detailed fullscreen tracker view.
Also check out Where is Comet 123P/West-Hartley?, a page that provides all the information needed to find Comet 123P/West-Hartley in the sky and additional links to sky charts.
Celestial Coordinates
Apparent
J2000
Additional Information
The observed values of Magnitude, Coma Diameter and Tail Length are derived from the most recent observation recorded at the Comet Observers Database. The value of Predicted Magnitude comes from the JPL Horizons ephemerides service and, in the case of comets, might be inaccurate given the highly dynamic and unpredictable behavior of these objects. When available, please refer to the Observed Magnitude value and consider the Predicted 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.
Rise and Set Times
Today's rise, transit and set times of Comet 123P/West-Hartley from Greenwich, UK (all times relative to the local timezone Europe/London):
- 123P/West-Hartley is above the horizon from Greenwich, UK.
- Right now it is placed in the South-East direction at an altitude of 40.01° above the horizon.
- Given its current magnitude, 123P/West-Hartley is visible only through long exposure photography.
- Go to interactive sky chart
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Distance from Earth
The distance of Comet 123P/West-Hartley from Earth is currently
The following chart shows the distance of Comet 123P/West-Hartley 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.
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 123P/West-Hartley from Earth is also available as a real time updated value in the Live Position and Data Tracker.
Closest Approach
Between 1 January 2000 and 31 December 2099, the closest approach of Comet 123P/West-Hartley to Earth happens on Thu Feb 28 2019 at a distance of 1.199581 Astronomical Units, or 179,454,775 kilometers:
NOTE: values for the closest approach are computed with a sampling interval of 1 day.
Light Curve
The following chart is the predicted light curve (visual magnitude as a function of time) of Comet 123P/West-Hartley, 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.
Orbital Elements
The following table lists the orbital elements of Comet 123P/West-Hartley at epoch 18 September 2015 00:00 UTC (JD: 2457284.5). Source: JPL Small-Body Database
| Element | Symbol | Value |
|---|---|---|
| Orbit eccentricity | e | 0.44927022 |
| Orbit inclination | i | 15.35454558° |
| Perihelion distance | q | 2.12610687 AU 318,061,062 km |
| Aphelion distance | Q |
5.59494602 AU 836,992,012 km |
| Semi-major axis | a |
3.86052645 AU 577,526,537 km |
| Orbital period | period |
7.5854 years 2,770.5642 days |
| Date of perihelion transit | Tp | 2019-Feb-04 08:09:24 2,458,518.8399 JD |
| Next perihelion transit | 2026-Sep-05 21:41 2,461,289.4041 JD |
|
| Argument of perihelion | peri | 102.91844683507° |
| Longitude of the ascending node | node | 46.527373044969° |
| Mean anomaly | M | 199.61304892378° |
| Mean motion | n | 0.12993743°/day |
View Comet 123P/West-Hartley in the 3D Solar System Simulator
15 Days Ephemeris
The following table lists the ephemerides of Comet 123P/West-Hartley computed for the past and next 7 days, with a 24 hours interval. Apparent celestial coordinates are provided.
| Date | Right AscensionR.A. | DeclinationDec. | MagnitudeMag | Constellation |
|---|---|---|---|---|
| 2025 May 09 | 02h 22m 45s | +11° 26’ 37” | 22.25 | Aries |
| 2025 May 10 | 02h 23m 50s | +11° 33’ 30” | 22.24 | Aries |
| 2025 May 11 | 02h 24m 55s | +11° 40’ 21” | 22.23 | Aries |
| 2025 May 12 | 02h 26m 00s | +11° 47’ 11” | 22.21 | Aries |
| 2025 May 13 | 02h 27m 06s | +11° 54’ 00” | 22.20 | Aries |
| 2025 May 14 | 02h 28m 11s | +12° 00’ 48” | 22.19 | Aries |
| 2025 May 15 | 02h 29m 16s | +12° 07’ 36” | 22.18 | Aries |
| 2025 May 16 | 02h 30m 21s | +12° 14’ 21” | 22.17 | Aries |
| 2025 May 17 | 02h 31m 27s | +12° 21’ 06” | 22.16 | Aries |
| 2025 May 18 | 02h 32m 32s | +12° 27’ 48” | 22.15 | Aries |
| 2025 May 19 | 02h 33m 38s | +12° 34’ 31” | 22.13 | Aries |
| 2025 May 20 | 02h 34m 43s | +12° 41’ 11” | 22.12 | Aries |
| 2025 May 21 | 02h 35m 49s | +12° 47’ 52” | 22.11 | Aries |
| 2025 May 22 | 02h 36m 55s | +12° 54’ 30” | 22.10 | Aries |
Additional Resources on TheSkyLive
- Comet 123P/West-Hartley: Complete reference information on TheSkyLive.com
- Where is Comet 123P/West-Hartley?: Key information on locating Comet 123P/West-Hartley in the sky.
- Distance from Earth: Find out how far Comet 123P/West-Hartley is from Earth right now.
- How Bright is Comet 123P/West-Hartley?: Current visual brightness (magnitude) and apparent size.
- Rise and Set Times: Comet 123P/West-Hartley's rise and set times from your location.
- Interactive Sky Map: planetarium-style interactive visualization of Comet 123P/West-Hartley's position in the sky.
- Live Position Tracker: high precision position tracker with deep space imagery.
- Ephemeris: 15 days Comet 123P/West-Hartley's computed ephemeris.
- Orbital elements: information about Comet 123P/West-Hartley orbital parameters.
- Orbit Visualization. 3d interactive visualization showing the orbit of Comet 123P/West-Hartley with respect to the major Solar System objects.