C/2025 B2 (Borisov) |
ephemeris |
date |
magn |
radius |
delta |
ra |
dec |
elong |
phase |
PA |
Today | 16 Oct 2025 | 20.1 | 8.472 AU | 8.265 AU | 07h48m | +85°16' | 98.6° | 6.7° | 276° |
Nearest approach | 14 Dec 2025 | 20.0 | 8.398 AU | 8.000 AU | 21h06m | +85°37' | 110.7° | 6.3° | 53° |
Perihelion | 11 Sep 2026 | 20.0 | 8.240 AU | 8.294 AU | 16h37m | +78°13' | 83.4° | 7.0° | 81° |
C/2025 B2 (Borisov)- 2025-10-16
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. (6.2 + 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/2025 B2 (Borisov) are:
e (Eccentricity) : 1.0012170
q (Perihelion distance) : 8.2401010
i (Inclination) : 91.74470
Ω (Longitude of ascending node) : 84.86660
ω (Argument of perihelion) : 78.82330
L (Longitude of perihelion) : 76.10664
B (Latitude of perihelion) : 78.68966
T (Time of perihelion passage) : 2461294.75030
Epoch : 2025 Oct 15
Reference : MPEC 2025-R69
Classification(s): : Nearly isotropic; New (a > 10000 AU)
Ephemerides
Date Time RA (2000) DEC (2000) delta radius elong phase PA magn
2025-10-15 00:00 UT 07 45 40.1 +84 58 27 8.282 8.475 97.8 6.7 277 20.1
2025-10-16 00:00 UT 07 47 12.4 +85 07 49 8.273 8.474 98.2 6.7 277 20.1
2025-10-16 22:48 UT 07 48 40.4 +85 16 44 8.265 8.472 98.6 6.7 276 20.1
2025-10-17 00:00 UT 07 48 45.0 +85 17 12 8.265 8.472 98.7 6.7 276 20.1
2025-10-18 00:00 UT 07 50 18.0 +85 26 37 8.256 8.471 99.1 6.7 276 20.1
2025-10-19 00:00 UT 07 51 51.5 +85 36 03 8.248 8.469 99.5 6.7 275 20.1
2025-10-20 00:00 UT 07 53 25.5 +85 45 29 8.240 8.468 99.9 6.7 275 20.1
2025-10-21 00:00 UT 07 55 00.0 +85 54 57 8.232 8.467 100.3 6.6 274 20.1
2025-10-22 00:00 UT 07 56 35.1 +86 04 26 8.223 8.465 100.7 6.6 273 20.1
2025-10-23 00:00 UT 07 58 10.9 +86 13 55 8.216 8.464 101.1 6.6 273 20.0
2025-10-24 00:00 UT 07 59 47.5 +86 23 26 8.208 8.463 101.5 6.6 272 20.0
2025-10-25 00:00 UT 08 01 25.0 +86 32 57 8.200 8.461 101.9 6.6 272 20.0
2025-10-26 00:00 UT 08 03 03.5 +86 42 28 8.193 8.460 102.3 6.6 271 20.0
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.