Comet 17P/Holmes
Comet 17P/Holmes is in the constellation of
Crater,
at a distance of
Finder Charts
View interactive star map
High precision deep sky finder chart, 60 arcmin wide, showing where Comet 17P/Holmes is right now. Click on the image to see a more detailed fullscreen tracker view.
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.
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 17P/Holmes from Greenwich, UK (all times relative to the local timezone Europe/London):
- 17P/Holmes is above the horizon from Greenwich, UK.
- Right now it is placed in the South direction at an altitude of 24.07° above the horizon.
- Given its current magnitude, 17P/Holmes is visible only through long exposure photography.
- Go to interactive sky chart
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.
Distance from Earth
The distance of Comet 17P/Holmes from Earth is currently
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.
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
Between 1 January 2000 and 31 December 2099, the closest approach of Comet 17P/Holmes to Earth happens on Thu Aug 20 2048 at a distance of 1.146026 Astronomical Units, or 171,443,013 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 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.
Orbital Elements
The following table lists the orbital elements of Comet 17P/Holmes at epoch 18 October 2016 00:00 UTC (JD: 2457680.5). Source: JPL Small-Body Database
| Element | Symbol | Value |
|---|---|---|
| Orbit eccentricity | e | 0.43015482 |
| Orbit inclination | i | 19.07035853° |
| Perihelion distance | q | 2.06632925 AU 309,118,457 km |
| Aphelion distance | Q |
5.18591870 AU 775,802,397 km |
| Semi-major axis | a |
3.62612398 AU 542,460,427 km |
| Orbital period | period |
6.9051 years 2,522.1006 days |
| Date of perihelion transit | Tp | 2014-Mar-26 17:17:14 2,456,743.2203 JD |
| Next perihelion transit | 2021-Feb-19 19:42 2,459,265.3209 JD |
|
| Argument of perihelion | peri | 24.738506005017° |
| Longitude of the ascending node | node | 326.77381045426° |
| Mean anomaly | M | 133.78558143669° |
| Mean motion | n | 0.14273816°/day |
Orbit Visualization
View Comet 17P/Holmes in the 3D Solar System Simulator
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. Apparent celestial coordinates are provided.
| Date | Right AscensionR.A. | DeclinationDec. | MagnitudeMag | Constellation |
|---|---|---|---|---|
| 2025 Apr 05 | 11h 45m 31s | -14° 42’ 04” | 22.86 | Crater |
| 2025 Apr 06 | 11h 44m 55s | -14° 38’ 44” | 22.86 | Crater |
| 2025 Apr 07 | 11h 44m 19s | -14° 35’ 22” | 22.86 | Crater |
| 2025 Apr 08 | 11h 43m 44s | -14° 31’ 58” | 22.86 | Crater |
| 2025 Apr 09 | 11h 43m 09s | -14° 28’ 33” | 22.86 | Crater |
| 2025 Apr 10 | 11h 42m 34s | -14° 25’ 06” | 22.86 | Crater |
| 2025 Apr 11 | 11h 42m 00s | -14° 21’ 37” | 22.86 | Crater |
| 2025 Apr 12 | 11h 41m 27s | -14° 18’ 08” | 22.86 | Crater |
| 2025 Apr 13 | 11h 40m 54s | -14° 14’ 38” | 22.86 | Crater |
| 2025 Apr 14 | 11h 40m 20s | -14° 11’ 07” | 22.86 | Crater |
| 2025 Apr 15 | 11h 39m 48s | -14° 07’ 36” | 22.86 | Crater |
| 2025 Apr 16 | 11h 39m 17s | -14° 04’ 04” | 22.86 | Crater |
| 2025 Apr 17 | 11h 38m 46s | -14° 00’ 31” | 22.86 | Crater |
| 2025 Apr 18 | 11h 38m 15s | -13° 56’ 59” | 22.87 | Crater |
Additional Resources
- Position and finder charts (see also Where is Comet 17P/Holmes?)
- Distance from Earth (see also How far is Comet 17P/Holmes from Earth?)
- When does Comet 17P/Holmes rise and set?
- Brightness (see also How bright is Comet 17P/Holmes?)
- Orbital elements. Detailed information about Comet 17P/Holmes orbital parameters.
- Interactive orbit visualization. 3d visualization showing the orbit of Comet 17P/Holmes with respect to the major Solar System objects.
- 15 days ephemerides. Table showing celestial coordinates and magnitude of Comet 17P/Holmes for the past and next 7 days.
- Interactive sky chart. An online planetarium application that shows where to locate Comet 17P/Holmes in the sky from your location.
- Live position tracker. A high precision sky chart that uses real deep sky imagery to help locate Comet 17P/Holmes with your telescope or on your astrophotographies.