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🌎  Greenwich, United Kingdom [change]

Comet Leonard (C/2021 A1)

Comet Leonard (C/2021 A1) is currently in the constellation of Ursa Major. The current Right Ascension of Comet Leonard (C/2021 A1) is 11h 44m 13s and the Declination is +35° 19’ 19” (topocentric coordinates computed for the selected location: Greenwich, United Kingdom [change]). The current estimated magnitude of Comet Leonard (C/2021 A1) is 13.66 (JPL) while the latest observed magnitude is 12.3 (COBS).

Summary of key facts about Comet Leonard (C/2021 A1) [tip: you can also create a Quick Access page for this data if you access it frequently and would like to have a simpler view]:

11h 44m 13s
+35° 19’ 19”
Ursa Major
  • C/2021 A1 (Leonard) is above the horizon from Greenwich, United Kingdom [change].
  • It is visible looking in the West-South-West direction at an altitude of 64° above the horizon.
  • Given its current magnitude, C/2021 A1 (Leonard) is visible with the help of a telescope havng an aperture of 8 inches (200mm) or more.
  • See also C/2021 A1 (Leonard) rise and set times.
  • 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.

Additional information about Comet Leonard (C/2021 A1) available on TheSkyLive:

Available Resources

Comet Leonard (C/2021 A1) Position and Finder Charts

Below we provide Comet Leonard (C/2021 A1) finder charts showing where the object is right now in the sky with respect to the brightest stars. The first finder chart has a field of view of 50 degrees, while the second one has a field of view of 10 degrees. Click on each finder chart to access a full screen interactive Online Planetarium.

Map showing Comet Leonard (C/2021 A1) in Ursa Major on October, 26 2021
Field of view: 50x30 degrees
View fullscreen
Map showing Comet Leonard (C/2021 A1) in Ursa Major on October, 26 2021
Field of view: 10x6 degrees
View fullscreen
 = visible to the naked eye
 = binocular, brighter than 10th magnitude
= current altitude ≥ 30°   = current altitude < 30°   = below the horizon
Location: Greenwich, United Kingdom [change]

Higher precision deep sky finder chart, 60 arcmin wide, showing where Comet Leonard (C/2021 A1) is right now. Click on the image to see a more detailed fullscreen tracker view.

C/2021 A1 (Leonard)
RA: 11h 44m 13s
Dec: +35° 19’ 19”
Deep sky finder chart for Comet Leonard (C/2021 A1)
Field of view: 60x40 arcmins
View fullscreen

Also check out Where is Comet Leonard (C/2021 A1)?, a page that provides all the information needed to find Comet Leonard (C/2021 A1) in the sky and additional links to sky charts.

Comet Leonard (C/2021 A1) Distance from Earth

The distance of Comet Leonard (C/2021 A1) from Earth is currently 260,142,267 kilometers, equivalent to 1.738944 Astronomical Units. Light takes 14 minutes and 27.7412 seconds to travel from Comet Leonard (C/2021 A1) and arrive to us.

14 minutes and 27.7412 seconds

The following chart shows the distance of Comet Leonard (C/2021 A1) 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.

Distance of Comet Leonard (C/2021 A1) from Earth between January 2013 and December 2100

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 C/2021 A1 (Leonard) from Earth is also available as a real time updated value in the Live Position and Data Tracker.

Closest approach of Comet Leonard (C/2021 A1) to Earth

Between January 2013 and December 2100, the closest approach of Comet Leonard (C/2021 A1) to Earth happens on Mon Dec 13 2021 at a distance of 0.233987 Astronomical Units, or 35,003,903 kilometers:

Mon Dec 13 2021

NOTE: values for the closest approach are computed with a sampling interval of 1 day.

Comet Leonard (C/2021 A1) brightness

The current visual magnitude of Comet Leonard (C/2021 A1) is 13.66.


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 behavior 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.

The following chart is the predicted light curve (visual magnitude as a function of time) of Comet Leonard (C/2021 A1), 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 Leonard (C/2021 A1) between January 2013 and December 2100

Comet Leonard (C/2021 A1) rise and set times

Location: Greenwich, United Kingdom [change]
Latitude: 51° 28’ 47” N
Longitude: 0° 00’ 00” E
Timezone: Europe/London

Today's Comet Leonard (C/2021 A1) rise, transit and set times from Greenwich, United Kingdom [change] are the following (all times relative to the local timezone Europe/London):

Azimuth: 54.7°
Max altitude: 73.8°
Azimuth: 305.3°

The rise and set times are defined as the time at which the upper limb of Comet Leonard (C/2021 A1) touches the horizon, considering the effect of the atmospheric refraction. As the atmospheric conditions cannot be modeled precisely the times reported here should be considered correct with an approximation of few minutes.

Comet Leonard (C/2021 A1) 15 Days Ephemeris

The following table lists the ephemerides of Comet Leonard (C/2021 A1) computed for the past and next 7 days, with a 24 hours interval. Click on each row of the table to locate Comet Leonard (C/2021 A1) in our Online Planetarium at the chosen date.

Date Right AscensionR.A. DeclinationDec. MagnitudeMag Constellation
2021 Oct 19 11h 35m 54s +35° 57’ 29” 14.12 Ursa Major
2021 Oct 20 11h 36m 57s +35° 52’ 13” 14.06 Ursa Major
2021 Oct 21 11h 38m 03s +35° 46’ 59” 14.01 Ursa Major
2021 Oct 22 11h 39m 07s +35° 41’ 48” 13.94 Ursa Major
2021 Oct 23 11h 40m 14s +35° 36’ 42” 13.88 Ursa Major
2021 Oct 24 11h 41m 21s +35° 31’ 37” 13.82 Ursa Major
2021 Oct 25 11h 42m 30s +35° 26’ 36” 13.76 Ursa Major
2021 Oct 26 11h 43m 40s +35° 21’ 38” 13.69 Ursa Major
2021 Oct 27 11h 44m 51s +35° 16’ 44” 13.62 Ursa Major
2021 Oct 28 11h 46m 03s +35° 11’ 50” 13.56 Ursa Major
2021 Oct 29 11h 47m 17s +35° 07’ 00” 13.49 Ursa Major
2021 Oct 30 11h 48m 32s +35° 02’ 13” 13.42 Ursa Major
2021 Oct 31 11h 49m 48s +34° 57’ 28” 13.34 Ursa Major
2021 Nov 01 11h 51m 06s +34° 52’ 42” 13.27 Ursa Major