The Solar System at your Fingertips
Comets » 

Comet 21P/Giacobini-Zinner

Available Resources

Comet 21P/Giacobini-Zinner Sky Charts and Coordinates

This is a simplified sky chart, showing where Comet 21P/Giacobini-Zinner is now with respect to the brightest stars and constellations.

More advanced sky charts are available on TheSkyLive for this object: 1) the Online Planetarium which is interactive and allows to select dates and additional objects to visualize; and 2) the Live Position and Data Tracker which provides the highest precision position data and features deep sky imagery from the Digitized Sky Survey.

Comet 21P/Giacobini-Zinner in Cygnus on June, 21 2018
High Precision Live Sky Chart
21h 05m 38s
+44° 23’ 12”
14.90
 = visible to the naked eye
 = binocular, brighter than 10th magnitude
= current altitude ≥ 30°   = current altitude < 30°   = below the horizon
Location: Greenwich, United Kingdom [change]

Comet 21P/Giacobini-Zinner Rise and Set Times

Comet 21P/Giacobini-Zinner is circumpolar from Greenwich, United Kingdom [change] and transits at 03:08 UTC (altitude: 82.9°)

Comet 21P/Giacobini-Zinner Orbit Diagram

This 3d orbit diagram is a feature of our 3D Solar System Simulator and shows the orbit of Comet 21P/Giacobini-Zinner with respect of the Sun and the orbits of the major planets. The position of Comet 21P/Giacobini-Zinner 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 21P/Giacobini-Zinner
View Comet 21P/Giacobini-Zinner in the 3D Solar System Simulator

Comet 21P/Giacobini-Zinner 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. Click on each row of the table to locate Comet 21P/Giacobini-Zinner in our Online Planetarium at the chosen date.

Date MagnitudeMag Right AscensionR.A. DeclinationDec. Constellation
2018 Jun 14 15.18 20h 51m 57s +40° 24’ 19” Cygnus
2018 Jun 15 15.14 20h 53m 48s +40° 58’ 11” Cygnus
2018 Jun 16 15.10 20h 55m 42s +41° 32’ 09” Cygnus
2018 Jun 17 15.06 20h 57m 38s +42° 06’ 14” Cygnus
2018 Jun 18 15.02 20h 59m 35s +42° 40’ 23” Cygnus
2018 Jun 19 14.98 21h 01m 33s +43° 14’ 35” Cygnus
2018 Jun 20 14.94 21h 03m 34s +43° 48’ 52” Cygnus
2018 Jun 21 14.90 21h 05m 38s +44° 23’ 12” Cygnus
2018 Jun 22 14.86 21h 07m 42s +44° 57’ 36” Cygnus
2018 Jun 23 14.82 21h 09m 51s +45° 32’ 02” Cygnus
2018 Jun 24 14.78 21h 12m 01s +46° 06’ 29” Cygnus
2018 Jun 25 14.74 21h 14m 15s +46° 40’ 59” Cygnus
2018 Jun 26 14.69 21h 16m 31s +47° 15’ 30” Cygnus
2018 Jun 27 14.65 21h 18m 50s +47° 50’ 02” Cygnus

Distance of Comet 21P/Giacobini-Zinner from Earth

The following chart shows the distance of Comet 21P/Giacobini-Zinner from Earth as a function of time. Distance data is measured in Astronomical Units and sampled with a 2 days interval.

The reported distances might be inaccurate around the times of closest approach for objects passing extremely close to Earth. The value of the distance of 21P/Giacobini-Zinner is also available as a real time updated value in the Live Position and Data Tracker.

Distance of Comet 21P/Giacobini-Zinner from Earth between January 2013 and December 2075

Light Curve of Comet 21P/Giacobini-Zinner

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.

Predicted magnitude of Comet 21P/Giacobini-Zinner between January 2013 and December 2075

Comet 21P/Giacobini-Zinner Orbital Elements

The following table lists the orbital elements of Comet 21P/Giacobini-Zinner at epoch 29 December 2017 00:00 UTC (JD: 2458117.5). Source: JPL Small-Body Database

Element Symbol Value
Orbit eccentricity e 0.71048685
Orbit inclination i 32.00024171°
Perihelion distance q 1.01315110 AU
151,565,248 km
Aphelion distance Q 5.98584778 AU
895,470,083 km
Semi-major axis a 3.49949944 AU
523,517,666 km
Orbital period period 6.5500 years
2,391.1527 days
Date of perihelion transit Tp 2018-Sep-10 06:27:47
2,458,371.7693 JD
Argument of perihelion peri 172.83191932167°
Longitude of the ascending node node 195.40028173068°
Mean anomaly M 321.71848657008°
Mean motion n 0.15055500°/day
Closest approach to Earth* 2058-Sep-18
Distance of closest approach* 0.37340131 AU
55,860,041 km

* NOTE: values for the closest approach are computed for the time interval between 2013-Jan-01 and 2075-Dec-31, with a sampling interval of 1 day.