| 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) |
| 2026-07-29 00:00 |
10:39:27.18 |
-30:40:59.4 |
HIP 52297 |
22.75 |
| 2026-07-29 12:00 |
10:39:40.13 |
-30:41:25.8 |
HIP 52297 |
19.95 |
| 2026-07-30 00:00 |
10:39:53.12 |
-30:41:53.3 |
HIP 52297 |
17.15 |
| 2026-07-30 12:00 |
10:40:06.15 |
-30:42:21.6 |
HIP 52297 |
14.34 |
| 2026-07-31 00:00 |
10:40:19.22 |
-30:42:50.9 |
HIP 52297 |
11.54 |
| 2026-07-31 12:00 |
10:40:32.32 |
-30:43:21.1 |
HIP 52297 |
8.75 |
| 2026-08-01 00:00 |
10:40:45.46 |
-30:43:52.2 |
HIP 52297 |
6.02 |
| 2026-08-01 12:00 |
10:40:58.64 |
-30:44:24.3 |
HIP 52297 |
3.50 |
| 2026-08-02 00:00 |
10:41:11.84 |
-30:44:57.3 |
HIP 52297 |
2.19 |
| 2026-08-02 12:00 |
10:41:25.09 |
-30:45:31.2 |
HIP 52297 |
3.75 |
| 2026-08-03 00:00 |
10:41:38.37 |
-30:46:06.1 |
HIP 52336 |
1.51 |
| 2026-08-03 12:00 |
10:41:51.68 |
-30:46:41.8 |
HIP 52336 |
2.45 |
| 2026-08-04 00:00 |
10:42:05.02 |
-30:47:18.5 |
HIP 52336 |
5.19 |
| 2026-08-04 12:00 |
10:42:18.39 |
-30:47:56.1 |
HIP 52336 |
8.08 |
| 2026-08-05 00:00 |
10:42:31.80 |
-30:48:34.6 |
HIP 52336 |
11.00 |
| 2026-08-05 12:00 |
10:42:45.24 |
-30:49:14.1 |
HIP 52336 |
13.95 |
| 2026-08-06 00:00 |
10:42:58.71 |
-30:49:54.4 |
HIP 52336 |
16.91 |
| 2026-08-06 12:00 |
10:43:12.20 |
-30:50:35.7 |
HIP 52336 |
19.88 |
| 2026-08-07 00:00 |
10:43:25.73 |
-30:51:17.9 |
HIP 52336 |
22.87 |
| 2026-08-07 12:00 |
10:43:39.29 |
-30:52:01.0 |
HIP 52596 |
21.22 |
| 2026-08-08 00:00 |
10:43:52.87 |
-30:52:45.0 |
HIP 52596 |
18.51 |
| 2026-08-08 12:00 |
10:44:06.48 |
-30:53:29.9 |
HIP 52596 |
15.91 |
| 2026-08-09 00:00 |
10:44:20.12 |
-30:54:15.7 |
HIP 52596 |
13.48 |
| 2026-08-09 12:00 |
10:44:33.78 |
-30:55:02.4 |
HIP 52596 |
11.35 |
| 2026-08-10 00:00 |
10:44:47.47 |
-30:55:50.0 |
HIP 52596 |
9.72 |
| 2026-08-10 12:00 |
10:45:01.19 |
-30:56:38.5 |
HIP 52596 |
8.87 |
| 2026-08-11 00:00 |
10:45:14.93 |
-30:57:27.9 |
HIP 52596 |
9.06 |
| 2026-08-11 12:00 |
10:45:28.69 |
-30:58:18.2 |
HIP 52646 |
8.87 |
| 2026-08-12 00:00 |
10:45:42.48 |
-30:59:09.4 |
HIP 52646 |
8.22 |
| 2026-08-12 12:00 |
10:45:56.29 |
-31:00:01.5 |
HIP 52646 |
8.70 |
| 2026-08-13 00:00 |
10:46:10.12 |
-31:00:54.5 |
HIP 52646 |
10.16 |
| 2026-08-13 12:00 |
10:46:23.97 |
-31:01:48.3 |
HIP 52646 |
12.26 |
| 2026-08-14 00:00 |
10:46:37.84 |
-31:02:43.1 |
HIP 52646 |
14.73 |
| 2026-08-14 12:00 |
10:46:51.74 |
-31:03:38.7 |
HIP 52646 |
17.42 |
| 2026-08-15 00:00 |
10:47:05.65 |
-31:04:35.2 |
HIP 52646 |
20.24 |
| 2026-08-15 12:00 |
10:47:19.58 |
-31:05:32.6 |
HIP 52888 |
21.68 |
| 2026-08-16 00:00 |
10:47:33.52 |
-31:06:30.8 |
HIP 52888 |
18.84 |
| 2026-08-16 12:00 |
10:47:47.49 |
-31:07:29.9 |
HIP 52888 |
16.10 |
| 2026-08-17 00:00 |
10:48:01.47 |
-31:08:29.9 |
HIP 52888 |
13.56 |
| 2026-08-17 12:00 |
10:48:15.47 |
-31:09:30.7 |
HIP 52888 |
11.32 |
| 2026-08-18 00:00 |
10:48:29.48 |
-31:10:32.4 |
HIP 52888 |
9.64 |
| 2026-08-18 12:00 |
10:48:43.50 |
-31:11:35.0 |
HIP 52888 |
8.82 |
| 2026-08-19 00:00 |
10:48:57.54 |
-31:12:38.4 |
HIP 52888 |
9.12 |