Comet 21P/Giacobini-Zinner
Comet 21P/Giacobini-Zinner is in the constellation of
Serpens,
at a distance of
View interactive star map
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 21P/Giacobini-Zinner from Greenwich, UK (all times relative to the local timezone Europe/London):
- 21P/Giacobini-Zinner is below the horizon from Greenwich, UK.
- Given its current magnitude, 21P/Giacobini-Zinner 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.
Finder Charts
High precision deep sky finder chart, 60 arcmin wide, showing where Comet 21P/Giacobini-Zinner is right now. Click on the image to see a more detailed fullscreen tracker view.
Also check out Where is Comet 21P/Giacobini-Zinner?, a page that provides all the information needed to find Comet 21P/Giacobini-Zinner in the sky and additional links to sky charts.
Distance from Earth
The distance of Comet 21P/Giacobini-Zinner from Earth is currently
The following chart shows the distance of Comet 21P/Giacobini-Zinner 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 21P/Giacobini-Zinner from Earth is also available as a real time updated value in the Live Position and Data Tracker.
Closest Approach
Between 1 January 2013 and 30 December 2100, the closest approach of Comet 21P/Giacobini-Zinner to Earth happens on Fri Oct 28 2078 at a distance of 0.255783 Astronomical Units, or 38,264,665 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 21P/Giacobini-Zinner, 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 21P/Giacobini-Zinner at epoch 05 November 2017 00:00 UTC (JD: 2458063.5). Source: JPL Small-Body Database
| Element | Symbol | Value |
|---|---|---|
| Orbit eccentricity | e | 0.71046678 |
| Orbit inclination | i | 32.00303376° |
| Perihelion distance | q | 1.01349375 AU 151,616,507 km |
| Aphelion distance | Q |
5.98738696 AU 895,700,342 km |
| Semi-major axis | a |
3.50044036 AU 523,658,425 km |
| Orbital period | period |
6.5493 years 2,392.1172 days |
| Date of perihelion transit | Tp | 2018-Sep-10 06:22:16 2,458,371.7655 JD |
| Next perihelion transit | 2025-Mar-29 09:11 2,460,763.8826 JD |
|
| Argument of perihelion | peri | 172.80915964581° |
| Longitude of the ascending node | node | 195.40514495049° |
| Mean anomaly | M | 313.60780403717° |
| Mean motion | n | 0.15049430°/day |
Orbit Visualization
View Comet 21P/Giacobini-Zinner in the 3D Solar System Simulator
15 Days Ephemeris
The following table lists the ephemerides of Comet 21P/Giacobini-Zinner 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 |
|---|---|---|---|---|
| 2024 Sep 13 | 15h 21m 34s | +05° 09’ 59” | 18.78 | Serpens |
| 2024 Sep 14 | 15h 22m 39s | +05° 02’ 51” | 18.77 | Serpens |
| 2024 Sep 15 | 15h 23m 44s | +04° 55’ 43” | 18.76 | Serpens |
| 2024 Sep 16 | 15h 24m 51s | +04° 48’ 34” | 18.75 | Serpens |
| 2024 Sep 17 | 15h 25m 59s | +04° 41’ 26” | 18.74 | Serpens |
| 2024 Sep 18 | 15h 27m 08s | +04° 34’ 19” | 18.73 | Serpens |
| 2024 Sep 19 | 15h 28m 17s | +04° 27’ 10” | 18.72 | Serpens |
| 2024 Sep 20 | 15h 29m 28s | +04° 20’ 03” | 18.70 | Serpens |
| 2024 Sep 21 | 15h 30m 40s | +04° 12’ 57” | 18.69 | Serpens |
| 2024 Sep 22 | 15h 31m 53s | +04° 05’ 51” | 18.68 | Serpens |
| 2024 Sep 23 | 15h 33m 07s | +03° 58’ 45” | 18.67 | Serpens |
| 2024 Sep 24 | 15h 34m 21s | +03° 51’ 39” | 18.66 | Serpens |
| 2024 Sep 25 | 15h 35m 37s | +03° 44’ 35” | 18.64 | Serpens |
| 2024 Sep 26 | 15h 36m 54s | +03° 37’ 31” | 18.63 | Serpens |
Additional Resources
- Position and finder charts (see also Where is Comet 21P/Giacobini-Zinner?)
- Distance from Earth (see also How far is Comet 21P/Giacobini-Zinner from Earth?)
- When does Comet 21P/Giacobini-Zinner rise and set?
- Brightness (see also How bright is Comet 21P/Giacobini-Zinner?)
- Orbital elements. Detailed information about Comet 21P/Giacobini-Zinner orbital parameters.
- Interactive orbit visualization. 3d visualization showing the orbit of Comet 21P/Giacobini-Zinner with respect to the major Solar System objects.
- 15 days ephemerides. Table showing celestial coordinates and magnitude of Comet 21P/Giacobini-Zinner for the past and next 7 days.
- Interactive sky chart. An online planetarium application that shows where to locate Comet 21P/Giacobini-Zinner in the sky from your location.
- Live position tracker. A high precision sky chart that uses real deep sky imagery to help locate Comet 21P/Giacobini-Zinner with your telescope or on your astrophotographies.