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Comet 21P/Giacobini-Zinner

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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 Puppis on December, 15 2018
High Precision Live Sky Chart
 = visible to the naked eye
 = binocular, brighter than 10th magnitude
= current altitude ≥ 30°   = current altitude < 30°   = below the horizon
Location: Greenwich, United Kingdom [change]
06h 47m 21s
-39° 36’ 14”

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 behvior 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.

Comet 21P/Giacobini-Zinner Rise and Set Times

Comet 21P/Giacobini-Zinner is currently not visible from Greenwich, United Kingdom [change]

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 Right AscensionR.A. DeclinationDec. MagnitudeMag Constellation
2018 Dec 08 06h 57m 51s -39° 34’ 09” 14.54 Puppis
2018 Dec 09 06h 56m 26s -39° 36’ 55” 14.58 Puppis
2018 Dec 10 06h 54m 57s -39° 38’ 52” 14.62 Puppis
2018 Dec 11 06h 53m 30s -39° 40’ 00” 14.65 Puppis
2018 Dec 12 06h 52m 01s -39° 40’ 20” 14.69 Puppis
2018 Dec 13 06h 50m 33s -39° 39’ 52” 14.73 Puppis
2018 Dec 14 06h 49m 04s -39° 38’ 38” 14.77 Puppis
2018 Dec 15 06h 47m 35s -39° 36’ 37” 14.81 Puppis
2018 Dec 16 06h 46m 05s -39° 33’ 48” 14.85 Puppis
2018 Dec 17 06h 44m 36s -39° 30’ 15” 14.88 Puppis
2018 Dec 18 06h 43m 09s -39° 25’ 56” 14.92 Puppis
2018 Dec 19 06h 41m 40s -39° 20’ 53” 14.96 Puppis
2018 Dec 20 06h 40m 13s -39° 15’ 07” 15.00 Puppis
2018 Dec 21 06h 38m 45s -39° 08’ 39” 15.04 Columba

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 09 July 2018 00:00 UTC (JD: 2458309.5). Source: JPL Small-Body Database

Element Symbol Value
Orbit eccentricity e 0.71043804
Orbit inclination i 31.99742071°
Perihelion distance q 1.01281453 AU
151,514,897 km
Aphelion distance Q 5.98267993 AU
894,996,180 km
Semi-major axis a 3.49774723 AU
523,255,539 km
Orbital period period 6.5400 years
2,389.3571 days
Date of perihelion transit Tp 2018-Sep-10 06:40:48
2,458,371.7783 JD
Next perihelion transit 2025-Mar-26 15:14
2,460,761.1354 JD
Argument of perihelion peri 172.86224872992°
Longitude of the ascending node node 195.39123587667°
Mean anomaly M 350.61663752864°
Mean motion n 0.15066815°/day
Closest approach to Earth* 2018-Sep-11
Distance of closest approach* 0.39179612 AU
58,611,866 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.