| Parameter |
Value |
| Designation |
C/2021 T2 (Fuls) |
| Type |
C |
| Perihelion (tp_cal, UTC) |
2022-06-07T21:34:39.907200Z |
| Orbit solution date (soln_date, UTC) |
2023-01-14T00:13:00Z |
| Obs used |
183 |
| NEO |
- |
| M1 |
15.300 |
| K1 |
4.500 |
| PC |
- |
| Discovery observation (MPC, UTC) |
2021-10-02T09:01:40.224000Z |
| Discovery magnitude (MPC) |
19.87 G |
| Discovery observatory (MPC) |
G96 · University of Arizona Mt. Lemmon Survey |
Osculating Elements
| Parameter |
Value |
| Epoch (epoch_cal, TDB) |
2021-11-13.0000000 |
| e |
1.00014284 |
| q (au) |
1.247719 |
| a (au) |
-8734.775296 |
| i (deg) |
117.526989 |
| Ω (om, deg) |
223.231185 |
| ω (w, deg) |
263.592510 |
| M (ma, deg) |
-0.000250 |
Magnitude
Scatter + Global Linear
$$
M_a = (17.173 + 2.000\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
Model Parameters
| Parameter |
Value |
| H0 |
17.173 |
| n |
2.000 |
| gf |
1.000 |
| gb |
-0.684 |
| k |
0.800 |
| 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 |
| 2021-10-02 |
2021-12-19 |
-4.4532 |
+2.177 |
| 2021-12-19 |
2022-02-25 |
-13.3606 |
+5.458 |
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 |
13:56:32.76 |
+34:08:09.6 |
HIP 68147 |
19.22 |
| 2026-06-01 12:00 |
13:56:24.45 |
+34:07:47.0 |
HIP 68147 |
20.25 |
| 2026-06-02 00:00 |
13:56:16.21 |
+34:07:23.6 |
HIP 68147 |
21.37 |
| 2026-06-02 12:00 |
13:56:08.04 |
+34:06:59.4 |
HIP 68145 |
22.08 |
| 2026-06-03 00:00 |
13:55:59.94 |
+34:06:34.4 |
HIP 68145 |
22.70 |
| 2026-06-03 12:00 |
13:55:51.91 |
+34:06:08.5 |
HIP 68145 |
23.41 |
| 2026-06-04 00:00 |
13:55:43.95 |
+34:05:41.8 |
HIP 68145 |
24.20 |
| 2026-06-04 12:00 |
13:55:36.06 |
+34:05:14.3 |
HIP 68145 |
25.06 |
| 2026-06-05 00:00 |
13:55:28.24 |
+34:04:46.0 |
HIP 68145 |
25.99 |
| 2026-06-05 12:00 |
13:55:20.50 |
+34:04:17.0 |
HIP 68145 |
26.97 |
| 2026-06-06 00:00 |
13:55:12.82 |
+34:03:47.1 |
HIP 68145 |
27.99 |
| 2026-06-06 12:00 |
13:55:05.23 |
+34:03:16.4 |
HIP 67803 |
26.58 |
| 2026-06-07 00:00 |
13:54:57.70 |
+34:02:45.0 |
HIP 67803 |
25.03 |
| 2026-06-07 12:00 |
13:54:50.25 |
+34:02:12.7 |
HIP 67803 |
23.49 |
| 2026-06-08 00:00 |
13:54:42.87 |
+34:01:39.7 |
HIP 67803 |
21.97 |
| 2026-06-08 12:00 |
13:54:35.57 |
+34:01:06.0 |
HIP 67803 |
20.47 |
| 2026-06-09 00:00 |
13:54:28.34 |
+34:00:31.4 |
HIP 67803 |
18.98 |
| 2026-06-09 12:00 |
13:54:21.19 |
+33:59:56.2 |
HIP 67803 |
17.53 |
| 2026-06-10 00:00 |
13:54:14.11 |
+33:59:20.1 |
HIP 67803 |
16.09 |
| 2026-06-10 12:00 |
13:54:07.12 |
+33:58:43.3 |
HIP 67803 |
14.69 |
| 2026-06-11 00:00 |
13:54:00.19 |
+33:58:05.8 |
HIP 67803 |
13.33 |
| 2026-06-11 12:00 |
13:53:53.35 |
+33:57:27.6 |
HIP 67803 |
12.02 |
| 2026-06-12 00:00 |
13:53:46.58 |
+33:56:48.6 |
HIP 67803 |
10.77 |
| 2026-06-12 12:00 |
13:53:39.90 |
+33:56:08.9 |
HIP 67803 |
9.59 |
| 2026-06-13 00:00 |
13:53:33.29 |
+33:55:28.5 |
HIP 67803 |
8.53 |
| 2026-06-13 12:00 |
13:53:26.76 |
+33:54:47.4 |
HIP 67803 |
7.62 |
| 2026-06-14 00:00 |
13:53:20.31 |
+33:54:05.6 |
HIP 67803 |
6.91 |
| 2026-06-14 12:00 |
13:53:13.94 |
+33:53:23.1 |
HIP 67803 |
6.47 |
| 2026-06-15 00:00 |
13:53:07.65 |
+33:52:39.9 |
HIP 67803 |
6.33 |
| 2026-06-15 12:00 |
13:53:01.44 |
+33:51:56.0 |
HIP 67803 |
6.53 |
| 2026-06-16 00:00 |
13:52:55.31 |
+33:51:11.4 |
HIP 67803 |
7.02 |
| 2026-06-16 12:00 |
13:52:49.26 |
+33:50:26.2 |
HIP 67803 |
7.74 |
| 2026-06-17 00:00 |
13:52:43.30 |
+33:49:40.3 |
HIP 67803 |
8.63 |
| 2026-06-17 12:00 |
13:52:37.41 |
+33:48:53.8 |
HIP 67803 |
9.65 |
| 2026-06-18 00:00 |
13:52:31.61 |
+33:48:06.6 |
HIP 67803 |
10.74 |
| 2026-06-18 12:00 |
13:52:25.89 |
+33:47:18.8 |
HIP 67803 |
11.89 |
| 2026-06-19 00:00 |
13:52:20.26 |
+33:46:30.4 |
HIP 67803 |
13.08 |
| 2026-06-19 12:00 |
13:52:14.70 |
+33:45:41.3 |
HIP 67803 |
14.30 |
| 2026-06-20 00:00 |
13:52:09.23 |
+33:44:51.6 |
HIP 67803 |
15.54 |
| 2026-06-20 12:00 |
13:52:03.84 |
+33:44:01.3 |
HIP 67650 |
15.48 |
| 2026-06-21 00:00 |
13:51:58.54 |
+33:43:10.4 |
HIP 67650 |
14.31 |
| 2026-06-21 12:00 |
13:51:53.32 |
+33:42:18.9 |
HIP 67650 |
13.19 |
| 2026-06-22 00:00 |
13:51:48.18 |
+33:41:26.9 |
HIP 67650 |
12.11 |