C/2013 A1 (Siding Spring) |
ephemeris |
date |
magn |
radius |
delta |
ra |
dec |
elong |
phase |
PA |
Nearest approach | 4 Sep 2014 | 9.1 | 1.583 AU | 0.889 AU | 21h34m | -73°18' | 113.0° | 35.9° | 21° |
Perihelion | 24 Oct 2014 | 10.3 | 1.411 AU | 1.745 AU | 17h36m | -21°44' | 53.9° | 34.7° | 91° |
Today | 4 Apr 2025 | 23.6 | 25.522 AU | 25.032 AU | 09h36m | +34°37' | 118.3° | 2.0° | 121° |
C/2013 A1 (Siding Spring)- 2025-04-04
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/2013 A1 (Siding Spring) are:
e (Eccentricity) : 0.9998840
q (Perihelion distance) : 1.4113330
i (Inclination) : 129.15450
Ω (Longitude of ascending node) : 300.88820
ω (Argument of perihelion) : 2.53870
L (Longitude of perihelion) : 299.28460
B (Latitude of perihelion) : 1.96837
T (Time of perihelion passage) : 2456954.82720
Epoch : 2020 Sep 26
Reference : MPC103843
Classification(s): : Nearly isotropic; New (a > 10000 AU)
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 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. (8.20 + 5 log[∆] + 6.00 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
2025-04-04 00:00 UT 09 36 53.8 +34 37 15 25.019 25.519 119.0 2.0 121 23.6
2025-04-04 17:20 UT 09 36 48.6 +34 37 03 25.032 25.522 118.3 2.0 121 23.6
2025-04-05 00:00 UT 09 36 46.6 +34 36 58 25.037 25.524 118.1 2.0 121 23.6
2025-04-06 00:00 UT 09 36 39.4 +34 36 39 25.056 25.528 117.1 2.0 120 23.6
2025-04-07 00:00 UT 09 36 32.5 +34 36 19 25.075 25.533 116.2 2.0 120 23.6
2025-04-08 00:00 UT 09 36 25.7 +34 35 59 25.094 25.538 115.3 2.0 119 23.6
2025-04-09 00:00 UT 09 36 19.1 +34 35 37 25.113 25.542 114.3 2.0 119 23.6
2025-04-10 00:00 UT 09 36 12.6 +34 35 14 25.132 25.547 113.4 2.1 119 23.6
2025-04-11 00:00 UT 09 36 06.3 +34 34 50 25.151 25.552 112.5 2.1 118 23.6
2025-04-12 00:00 UT 09 36 00.2 +34 34 25 25.171 25.556 111.5 2.1 118 23.6
2025-04-13 00:00 UT 09 35 54.2 +34 33 59 25.190 25.561 110.6 2.1 117 23.7
2025-04-14 00:00 UT 09 35 48.4 +34 33 32 25.210 25.566 109.7 2.1 117 23.7
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.