C/2020 R4 (ATLAS) |
ephemeris |
date |
magn |
radius |
delta |
ra |
dec |
elong |
phase |
PA |
Perihelion | 2 Mar 2021 | 10.7 | 1.021 AU | 1.703 AU | 20h40m | -11°23' | 32.7° | 31.6° | 266° |
Nearest approach | 23 Apr 2021 | 9.2 | 1.336 AU | 0.458 AU | 16h15m | +29°00' | 127.6° | 36.6° | 222° |
Today | 22 Apr 2025 | 28.7 | 13.329 AU | 13.262 AU | 08h21m | +15°14' | 91.6° | 4.3° | 103° |
C/2020 R4 (ATLAS)- 2025-04-22
astro.vanbuitenen.nl
The interactive orbit chart above shows the comet's path through the solar system and its position at the given date.
Green and blue lines are shown perpendicular to the ecliptic plane: Green if the path is above the ecliptic plane, blue if it is below.
(Left-click and drag to rotate the view; Right-click and drag to move the view; Use scroll wheel to zoom in our out.)
The orbital elements of C/2020 R4 (ATLAS) are:
e (Eccentricity) : 0.9895330
q (Perihelion distance) : 1.0210650
i (Inclination) : 164.40750
Ω (Longitude of ascending node) : 323.23720
ω (Argument of perihelion) : 46.52670
L (Longitude of perihelion) : 277.78399
B (Latitude of perihelion) : 11.24836
T (Time of perihelion passage) : 2459275.77510
P (Orbital period in years) : 963.49
Epoch : 2025 Apr 21
Reference : MPEC 2022-K19
Classification(s): : Nearly isotropic; Returning (a < 10000 AU); External (P > 200 years)
The light curve chart below shows the estimated development of the comet's magnitude. Blue and black dots are visual and photometric CCD observations respectively from COBS or the MPC.
The gray curve is based on the absolute magnitude and slope parameter as calculated from the original MPEC, or the latest values provided by the MPC (13.50 + 5 log[∆] + 10.00 log[r]), whereas the red curve is being recalculated every 6 hours based on the available COBS/MPC observations (currently 9.39 + 5 log[∆] + 12.18 log[r]).
The all-sky chart below shows the path of the comet over the same period as the light curve. The comet's current position is marked yellow.
The following chart shows the short-term path of the comet in a field of view that is optimized for (~10x50) binoculars and finderscopes.
A more printer-friendly version of the same chart can be found further down this page as well.
The following chart shows the current location of the comet in a smaller, upside-down telescopic field of view.
A printable version of the short-term path of the comet in a field of view that is optimized for (~10x50) binoculars and finderscopes.
Ephemerides:
Date Time RA (2000) DEC (2000) delta radius elong phase PA magn
2025-04-22 00:00 UT 08 21 13.8 +15 14 21 13.247 13.325 92.2 4.3 103 28.7
2025-04-22 15:14 UT 08 21 12.5 +15 14 33 13.262 13.329 91.6 4.3 103 28.7
2025-04-23 00:00 UT 08 21 11.8 +15 14 40 13.271 13.331 91.2 4.3 103 28.7
2025-04-24 00:00 UT 08 21 10.1 +15 14 58 13.294 13.337 90.3 4.3 103 28.7
2025-04-25 00:00 UT 08 21 08.7 +15 15 15 13.317 13.343 89.3 4.3 103 28.7
2025-04-26 00:00 UT 08 21 07.6 +15 15 31 13.341 13.349 88.3 4.3 103 28.7
2025-04-27 00:00 UT 08 21 06.9 +15 15 46 13.364 13.355 87.3 4.3 104 28.7
2025-04-28 00:00 UT 08 21 06.4 +15 15 59 13.387 13.362 86.4 4.3 104 28.7
2025-04-29 00:00 UT 08 21 06.3 +15 16 12 13.411 13.368 85.4 4.3 104 28.7
2025-04-30 00:00 UT 08 21 06.4 +15 16 23 13.434 13.374 84.4 4.3 104 28.7
2025-05-01 00:00 UT 08 21 06.8 +15 16 33 13.457 13.380 83.4 4.3 104 28.8
2025-05-02 00:00 UT 08 21 07.6 +15 16 42 13.480 13.386 82.5 4.3 104 28.8
Terminology:
delta: distance between comet and earth in AU
radius: distance between comet and sun in AU
magn: magnitude (brightness) estimate
ra: right ascension in hours (24h = 360deg)
dec: declination in degrees
elong: elongation in degrees (angle sun-earth-comet)
phase: phase angle in degrees (angle sun-comet-earth)
AU: Astronomical Unit (mean distance between earth and sun: 149597870.7 km
Orbital elements usually provided by the MPC (Minor Planet Center).
Observations contributed by observers worldwide, via COBS (Comet Observation Database) or the MPC (Minor Planet Center)
Calculations by a modified version of AAPlus, a C# implementation of the AA+ project by PJ Naughter from the algorithms presented in the book "Astronomical Algorithms" by Jean Meeus.
NGC2000 dso catalog and star labels from VizieR as provided by the Strasbourg astronomical Data Center.
Tycho2 catalog from the ESO archive.