C/2023 T2 (Borisov)
| 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 |
-0.500 |
| 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) |
| 2026-02-03 00:00 |
11:00:03.11 |
-36:03:16.2 |
HIP 53694 |
29.00 |
| 2026-02-03 12:00 |
10:59:48.60 |
-36:04:25.5 |
HIP 53694 |
26.94 |
| 2026-02-04 00:00 |
10:59:33.99 |
-36:05:33.2 |
HIP 53694 |
25.13 |
| 2026-02-04 12:00 |
10:59:19.29 |
-36:06:39.2 |
HIP 53694 |
23.63 |
| 2026-02-05 00:00 |
10:59:04.50 |
-36:07:43.5 |
HIP 53694 |
22.50 |
| 2026-02-05 12:00 |
10:58:49.62 |
-36:08:46.2 |
HIP 53544 |
19.98 |
| 2026-02-06 00:00 |
10:58:34.65 |
-36:09:47.1 |
HIP 53544 |
16.82 |
| 2026-02-06 12:00 |
10:58:19.60 |
-36:10:46.4 |
HIP 53544 |
13.66 |
| 2026-02-07 00:00 |
10:58:04.46 |
-36:11:43.9 |
HIP 53544 |
10.50 |
| 2026-02-07 12:00 |
10:57:49.25 |
-36:12:39.8 |
HIP 53544 |
7.36 |
| 2026-02-08 00:00 |
10:57:33.95 |
-36:13:33.9 |
HIP 53544 |
4.31 |
| 2026-02-08 12:00 |
10:57:18.57 |
-36:14:26.3 |
HIP 53544 |
1.88 |
| 2026-02-09 00:00 |
10:57:03.12 |
-36:15:17.0 |
HIP 53544 |
3.03 |
| 2026-02-09 12:00 |
10:56:47.59 |
-36:16:05.9 |
HIP 53544 |
5.97 |
| 2026-02-10 00:00 |
10:56:31.99 |
-36:16:53.2 |
HIP 53544 |
9.11 |
| 2026-02-10 12:00 |
10:56:16.32 |
-36:17:38.7 |
HIP 53544 |
12.31 |
| 2026-02-11 00:00 |
10:56:00.58 |
-36:18:22.4 |
HIP 53544 |
15.53 |
| 2026-02-11 12:00 |
10:55:44.78 |
-36:19:04.4 |
HIP 53544 |
18.76 |
| 2026-02-12 00:00 |
10:55:28.90 |
-36:19:44.7 |
HIP 53289 |
20.12 |
| 2026-02-12 12:00 |
10:55:12.97 |
-36:20:23.2 |
HIP 53289 |
16.92 |
| 2026-02-13 00:00 |
10:54:56.97 |
-36:21:00.0 |
HIP 53289 |
13.76 |
| 2026-02-13 12:00 |
10:54:40.92 |
-36:21:35.1 |
HIP 53289 |
10.68 |
| 2026-02-14 00:00 |
10:54:24.81 |
-36:22:08.4 |
HIP 53289 |
7.77 |
| 2026-02-14 12:00 |
10:54:08.64 |
-36:22:39.9 |
HIP 53289 |
5.34 |
| 2026-02-15 00:00 |
10:53:52.42 |
-36:23:09.7 |
HIP 53289 |
4.33 |
| 2026-02-15 12:00 |
10:53:36.15 |
-36:23:37.7 |
HIP 53289 |
5.57 |
| 2026-02-16 00:00 |
10:53:19.83 |
-36:24:04.0 |
HIP 53289 |
8.09 |
| 2026-02-16 12:00 |
10:53:03.46 |
-36:24:28.5 |
HIP 53289 |
11.06 |
| 2026-02-17 00:00 |
10:52:47.05 |
-36:24:51.2 |
HIP 53289 |
14.19 |
| 2026-02-17 12:00 |
10:52:30.60 |
-36:25:12.3 |
HIP 53235 |
16.90 |
| 2026-02-18 00:00 |
10:52:14.11 |
-36:25:31.5 |
HIP 53235 |
18.91 |
| 2026-02-18 12:00 |
10:51:57.57 |
-36:25:49.0 |
HIP 52981 |
20.53 |
| 2026-02-19 00:00 |
10:51:41.01 |
-36:26:04.8 |
HIP 52981 |
17.23 |
| 2026-02-19 12:00 |
10:51:24.41 |
-36:26:18.8 |
HIP 52981 |
13.95 |
| 2026-02-20 00:00 |
10:51:07.78 |
-36:26:31.0 |
HIP 52981 |
10.73 |
| 2026-02-20 12:00 |
10:50:51.12 |
-36:26:41.6 |
HIP 52981 |
7.62 |
| 2026-02-21 00:00 |
10:50:34.43 |
-36:26:50.4 |
HIP 52981 |
4.87 |
| 2026-02-21 12:00 |
10:50:17.72 |
-36:26:57.4 |
HIP 52981 |
3.48 |
| 2026-02-22 00:00 |
10:50:00.98 |
-36:27:02.7 |
HIP 52981 |
4.83 |
| 2026-02-22 12:00 |
10:49:44.23 |
-36:27:06.3 |
HIP 52981 |
7.58 |
| 2026-02-23 00:00 |
10:49:27.46 |
-36:27:08.2 |
HIP 52981 |
10.70 |
| 2026-02-23 12:00 |
10:49:10.67 |
-36:27:08.4 |
HIP 52923 |
11.63 |
| 2026-02-24 00:00 |
10:48:53.87 |
-36:27:06.8 |
HIP 52923 |
12.89 |