Comet C/2021 T4 (Lemmon)
Comet C/2021 T4 (Lemmon) is in the constellation of
Leo Minor,
at a distance of
Finder Charts
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High precision deep sky finder chart, 60 arcmin wide, showing where Comet C/2021 T4 (Lemmon) is right now. Click on the image to see a more detailed fullscreen tracker view.
Also check out Where is Comet C/2021 T4 (Lemmon)?, a page that provides all the information needed to find Comet C/2021 T4 (Lemmon) 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 C/2021 T4 (Lemmon) from Greenwich, UK (all times relative to the local timezone Europe/London):
- C/2021 T4 (Lemmon) is below the horizon from Greenwich, UK.
- Given its current magnitude, C/2021 T4 (Lemmon) is visible only through long exposure photography.
- Go to interactive sky chart
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Distance from Earth
The distance of Comet C/2021 T4 (Lemmon) from Earth is currently
The following chart shows the distance of Comet C/2021 T4 (Lemmon) 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 C/2021 T4 (Lemmon) 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 C/2021 T4 (Lemmon) to Earth happens on Fri Jul 21 2023 at a distance of 0.541555 Astronomical Units, or 81,015,514 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 C/2021 T4 (Lemmon), 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 C/2021 T4 (Lemmon) at epoch 13 April 2023 00:00 UTC (JD: 2460048.5). Source: JPL Small-Body Database
| Element | Symbol | Value |
|---|---|---|
| Orbit eccentricity | e | 0.99991819 |
| Orbit inclination | i | 160.77740884° |
| Perihelion distance | q | 1.48329798 AU 221,898,219 km |
| Aphelion distance | Q |
36,262.09015781 AU 5,424,731,485,618 km |
| Semi-major axis | a |
18,131.78672789 AU 2,712,476,691,919 km |
| Orbital period | period |
2,441,569.5804 years 891,783,289.2347 days |
| Date of perihelion transit | Tp | 2023-Jul-31 12:38:55 2,460,157.0270 JD |
| Next perihelion transit | 3610-Jun-07 01:23 894,243,446.2617 JD |
|
| Argument of perihelion | peri | 329.81392999632° |
| Longitude of the ascending node | node | 257.88231220148° |
| Mean anomaly | M | 359.99995618921° |
| Mean motion | n | 0.00000040°/day |
View Comet C/2021 T4 (Lemmon) in the 3D Solar System Simulator
15 Days Ephemeris
The following table lists the ephemerides of Comet C/2021 T4 (Lemmon) 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 Jun 06 | 10h 51m 37s | +27° 35’ 49” | 20.63 | Leo Minor |
| 2025 Jun 07 | 10h 51m 34s | +27° 33’ 20” | 20.64 | Leo Minor |
| 2025 Jun 08 | 10h 51m 31s | +27° 30’ 49” | 20.65 | Leo Minor |
| 2025 Jun 09 | 10h 51m 28s | +27° 28’ 16” | 20.65 | Leo Minor |
| 2025 Jun 10 | 10h 51m 27s | +27° 25’ 42” | 20.66 | Leo Minor |
| 2025 Jun 11 | 10h 51m 26s | +27° 23’ 07” | 20.67 | Leo Minor |
| 2025 Jun 12 | 10h 51m 25s | +27° 20’ 30” | 20.68 | Leo Minor |
| 2025 Jun 13 | 10h 51m 25s | +27° 17’ 52” | 20.69 | Leo Minor |
| 2025 Jun 14 | 10h 51m 25s | +27° 15’ 13” | 20.70 | Leo Minor |
| 2025 Jun 15 | 10h 51m 26s | +27° 12’ 33” | 20.71 | Leo Minor |
| 2025 Jun 16 | 10h 51m 28s | +27° 09’ 51” | 20.72 | Leo Minor |
| 2025 Jun 17 | 10h 51m 30s | +27° 07’ 09” | 20.73 | Leo Minor |
| 2025 Jun 18 | 10h 51m 32s | +27° 04’ 25” | 20.73 | Leo Minor |
| 2025 Jun 19 | 10h 51m 35s | +27° 01’ 41” | 20.74 | Leo Minor |
Additional Resources on TheSkyLive
- Comet C/2021 T4 (Lemmon): Complete reference information on TheSkyLive.com.
- Where is Comet C/2021 T4 (Lemmon)?: Key information on locating Comet C/2021 T4 (Lemmon) in the sky.
- Distance from Earth: Find out how far Comet C/2021 T4 (Lemmon) is from Earth right now.
- How Bright is Comet C/2021 T4 (Lemmon)?: Current visual brightness (magnitude) and apparent size.
- Rise and Set Times: Comet C/2021 T4 (Lemmon)'s rise and set times from your location.
- Interactive Sky Map: planetarium-style interactive visualization of Comet C/2021 T4 (Lemmon)'s position in the sky.
- Live Position Tracker: high precision position tracker with deep space imagery.
- Ephemeris: 15 days Comet C/2021 T4 (Lemmon)'s computed ephemeris.
- Orbital elements: information about Comet C/2021 T4 (Lemmon) orbital parameters.
- Orbit Visualization. 3d interactive visualization showing the orbit of Comet C/2021 T4 (Lemmon) with respect to the major Solar System objects.