C/2021 R7 (PANSTARRS) |
ephemeris |
date |
magn |
radius |
delta |
ra |
dec |
elong |
phase |
PA |
Perihelion | 17 Apr 2021 | 22.1 | 5.655 AU | 6.636 AU | 01h26m | +21°11' | 11.3° | 2.0° | 339° |
Nearest approach | 30 Sep 2021 | 21.5 | 5.780 AU | 4.793 AU | 00h30m | +13°44' | 169.1° | 1.9° | 185° |
Today | 13 Oct 2025 | 26.7 | 12.132 AU | 12.054 AU | 19h52m | -38°24' | 92.1° | 4.7° | 78° |
C/2021 R7 (PANSTARRS)- 2025-10-13
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.)
Light curve
The light curve chart below shows the estimated development of the comet's magnitude. Blue and black dots are visual and photometric CCD observations from COBS.
The light curve is based on the absolute magnitude and slope parameter as calculated from an MPEC, or the latest values provided by the minor planet center. (10.5 + 5 log[∆] + 10.0 log[r]). An additional green curve is displayed when an increase in apparent brightness is expected due to forward scattering of sunlight, which occurs when a dust-rich comet is located between the Earth and the Sun. (See Marcus 2007)
Charts
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.
Orbital elements
The orbital elements of C/2021 R7 (PANSTARRS) are:
e (Eccentricity) : 0.9945940
q (Perihelion distance) : 5.6550710
i (Inclination) : 158.87810
Ω (Longitude of ascending node) : 170.21260
ω (Argument of perihelion) : 140.42010
L (Longitude of perihelion) : 207.84990
B (Latitude of perihelion) : 13.27355
T (Time of perihelion passage) : 2459322.06670
P (Orbital period in years) : 33833.20
Epoch : 2025 Oct 12
Reference : MPEC 2022-X67
Classification(s): : Nearly isotropic; Returning (a < 10000 AU); External (P > 200 years)
Ephemerides
Date Time RA (2000) DEC (2000) delta radius elong phase PA magn
2025-10-13 00:00 UT 19 52 30.3 -38 25 49 12.033 12.127 93.0 4.7 78 26.7
2025-10-13 23:15 UT 19 52 22.6 -38 24 57 12.054 12.132 92.1 4.7 78 26.7
2025-10-14 00:00 UT 19 52 22.3 -38 24 55 12.055 12.132 92.1 4.7 78 26.7
2025-10-15 00:00 UT 19 52 14.8 -38 24 01 12.077 12.137 91.1 4.7 78 26.8
2025-10-16 00:00 UT 19 52 07.7 -38 23 05 12.099 12.142 90.1 4.7 79 26.8
2025-10-17 00:00 UT 19 52 01.0 -38 22 08 12.121 12.147 89.2 4.7 79 26.8
2025-10-18 00:00 UT 19 51 54.8 -38 21 11 12.142 12.153 88.2 4.7 79 26.8
2025-10-19 00:00 UT 19 51 49.1 -38 20 13 12.164 12.158 87.2 4.7 80 26.8
2025-10-20 00:00 UT 19 51 43.8 -38 19 14 12.186 12.163 86.3 4.7 80 26.8
2025-10-21 00:00 UT 19 51 38.9 -38 18 14 12.208 12.168 85.3 4.7 80 26.8
2025-10-22 00:00 UT 19 51 34.5 -38 17 14 12.230 12.173 84.4 4.7 81 26.8
2025-10-23 00:00 UT 19 51 30.5 -38 16 13 12.252 12.178 83.4 4.7 81 26.8
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.