| Parameter |
Value |
| Designation |
C/2023 T2 (Borisov) |
| Type |
C |
| Perihelion (tp_cal, UTC) |
2023-12-22T18:54:38.292480Z |
| Orbit solution date (soln_date, UTC) |
2024-04-13T16:42:50Z |
| Obs used |
368 |
| NEO |
- |
| M1 |
11.800 |
| K1 |
18.500 |
| PC |
0.030 |
| Discovery observation (MPC, UTC) |
2023-10-14T16:40:30.720000Z |
| Discovery magnitude (MPC) |
19.40 G |
| Discovery observatory (MPC) |
L51 · MARGO, Nauchnyi |
Osculating Elements
| Parameter |
Value |
| Epoch (epoch_cal, TDB) |
2023-11-23.0000000 |
| e |
0.99137332 |
| q (au) |
1.995438 |
| a (au) |
231.310079 |
| i (deg) |
48.596685 |
| Ω (om, deg) |
317.534632 |
| ω (w, deg) |
111.190785 |
| M (ma, deg) |
359.991654 |
Magnitude
Scatter + Global Linear
$$
M_a = (12.017 + 6.000\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
Model Parameters
| Parameter |
Value |
| H0 |
12.017 |
| n |
6.000 |
| gf |
1.000 |
| gb |
-0.998 |
| k |
1.000 |
| δ90 |
10.000 |
| Parameter |
Symbol |
Range |
Description |
| Absolute magnitude at 1 AU from Sun and Earth |
H0 |
-5 to 20 |
Intrinsic brightness of the comet |
| Photometric slope parameter |
n |
2 to 6 |
Rate of brightness change with heliocentric distance |
| Forward scattering asymmetry factor |
gf |
0.8 to 1 |
Degree of forward scattering |
| Backward scattering asymmetry factor |
gb |
-1 to -0.5 |
Degree of backward scattering |
| Partitioning coefficient |
k |
0.8 to 1 |
Ratio between forward/backward scattering contributions |
| Dust-to-gas brightness ratio |
δ90 |
1 to 10 |
Relative contribution of dust scattering to gas emission |
Reference: EPSC-DPS2025-160
Residuals (Piecewise)
$$\epsilon = a \log_{10} r_{\mathrm{au}} + b$$
| Start (UTC) |
End (UTC) |
a |
b |
| 2023-08-14 |
2023-12-19 |
+8.4189 |
-2.661 |
| 2023-12-31 |
2024-04-05 |
-9.5022 |
+2.693 |
log10 r = log10(heliocentric distance / AU), Δ = geocentric distance (AU)
Ephemeris
| Date/Time (UTC) |
RA (J2000) |
Dec (J2000) |
Nearest HIP |
Dist from HIP (arcmin) |
| 2026-06-01 00:00 |
10:21:40.57 |
-31:39:25.1 |
HIP 50641 |
16.96 |
| 2026-06-01 12:00 |
10:21:44.55 |
-31:38:01.4 |
HIP 50641 |
18.45 |
| 2026-06-02 00:00 |
10:21:48.65 |
-31:36:38.6 |
HIP 50641 |
19.98 |
| 2026-06-02 12:00 |
10:21:52.87 |
-31:35:16.5 |
HIP 50599 |
21.49 |
| 2026-06-03 00:00 |
10:21:57.20 |
-31:33:55.3 |
HIP 50599 |
22.43 |
| 2026-06-03 12:00 |
10:22:01.64 |
-31:32:34.9 |
HIP 50599 |
23.48 |
| 2026-06-04 00:00 |
10:22:06.19 |
-31:31:15.4 |
HIP 50924 |
24.53 |
| 2026-06-04 12:00 |
10:22:10.86 |
-31:29:56.6 |
HIP 50924 |
23.60 |
| 2026-06-05 00:00 |
10:22:15.65 |
-31:28:38.7 |
HIP 50924 |
22.73 |
| 2026-06-05 12:00 |
10:22:20.54 |
-31:27:21.7 |
HIP 50924 |
21.92 |
| 2026-06-06 00:00 |
10:22:25.54 |
-31:26:05.4 |
HIP 50924 |
21.19 |
| 2026-06-06 12:00 |
10:22:30.66 |
-31:24:50.1 |
HIP 50924 |
20.53 |
| 2026-06-07 00:00 |
10:22:35.88 |
-31:23:35.6 |
HIP 50924 |
19.96 |
| 2026-06-07 12:00 |
10:22:41.22 |
-31:22:21.9 |
HIP 50924 |
19.49 |
| 2026-06-08 00:00 |
10:22:46.66 |
-31:21:09.1 |
HIP 50924 |
19.13 |
| 2026-06-08 12:00 |
10:22:52.21 |
-31:19:57.2 |
HIP 50924 |
18.89 |
| 2026-06-09 00:00 |
10:22:57.87 |
-31:18:46.2 |
HIP 50924 |
18.76 |
| 2026-06-09 12:00 |
10:23:03.63 |
-31:17:36.0 |
HIP 50924 |
18.76 |
| 2026-06-10 00:00 |
10:23:09.50 |
-31:16:26.7 |
HIP 50924 |
18.89 |
| 2026-06-10 12:00 |
10:23:15.48 |
-31:15:18.4 |
HIP 50924 |
19.15 |
| 2026-06-11 00:00 |
10:23:21.56 |
-31:14:10.9 |
HIP 50896 |
18.85 |
| 2026-06-11 12:00 |
10:23:27.75 |
-31:13:04.3 |
HIP 50896 |
17.58 |
| 2026-06-12 00:00 |
10:23:34.04 |
-31:11:58.6 |
HIP 50896 |
16.42 |
| 2026-06-12 12:00 |
10:23:40.43 |
-31:10:53.8 |
HIP 50896 |
15.38 |
| 2026-06-13 00:00 |
10:23:46.93 |
-31:09:50.0 |
HIP 50896 |
14.50 |
| 2026-06-13 12:00 |
10:23:53.52 |
-31:08:47.0 |
HIP 50896 |
13.81 |
| 2026-06-14 00:00 |
10:24:00.22 |
-31:07:45.0 |
HIP 50896 |
13.33 |
| 2026-06-14 12:00 |
10:24:07.02 |
-31:06:43.9 |
HIP 50896 |
13.11 |
| 2026-06-15 00:00 |
10:24:13.92 |
-31:05:43.7 |
HIP 50896 |
13.15 |
| 2026-06-15 12:00 |
10:24:20.92 |
-31:04:44.5 |
HIP 50896 |
13.45 |
| 2026-06-16 00:00 |
10:24:28.01 |
-31:03:46.2 |
HIP 50896 |
14.01 |
| 2026-06-16 12:00 |
10:24:35.21 |
-31:02:48.9 |
HIP 50896 |
14.80 |
| 2026-06-17 00:00 |
10:24:42.50 |
-31:01:52.5 |
HIP 50896 |
15.78 |
| 2026-06-17 12:00 |
10:24:49.88 |
-31:00:57.1 |
HIP 50896 |
16.93 |
| 2026-06-18 00:00 |
10:24:57.36 |
-31:00:02.6 |
HIP 50896 |
18.21 |
| 2026-06-18 12:00 |
10:25:04.94 |
-30:59:09.0 |
HIP 50896 |
19.61 |
| 2026-06-19 00:00 |
10:25:12.61 |
-30:58:16.4 |
HIP 51038 |
18.54 |
| 2026-06-19 12:00 |
10:25:20.37 |
-30:57:24.8 |
HIP 51038 |
17.31 |
| 2026-06-20 00:00 |
10:25:28.22 |
-30:56:34.2 |
HIP 51038 |
16.21 |
| 2026-06-20 12:00 |
10:25:36.17 |
-30:55:44.5 |
HIP 51038 |
15.28 |
| 2026-06-21 00:00 |
10:25:44.20 |
-30:54:55.7 |
HIP 51038 |
14.56 |
| 2026-06-21 12:00 |
10:25:52.33 |
-30:54:08.0 |
HIP 51038 |
14.08 |
| 2026-06-22 00:00 |
10:26:00.54 |
-30:53:21.2 |
HIP 51038 |
13.88 |