| Parameter |
Value |
| Designation |
41P/Tuttle-Giacobini-Kresak |
| Type |
P |
| Perihelion (tp_cal, UTC) |
2017-04-12T18:04:18.526080Z |
| Orbit solution date (soln_date, UTC) |
2023-09-29T16:16:14Z |
| Obs used |
4300 |
| NEO |
Yes |
| M1 |
16.900 |
| K1 |
4.500 |
| PC |
- |
Osculating Elements
| Parameter |
Value |
| Epoch (epoch_cal, TDB) |
2017-04-14.0000000 |
| e |
0.66127330 |
| q (au) |
1.045043 |
| a (au) |
3.085209 |
| i (deg) |
9.228466 |
| Ω (om, deg) |
141.058972 |
| ω (w, deg) |
62.166743 |
| M (ma, deg) |
0.226802 |
Magnitude
Scatter + Global Linear
$$
M_a = (11.530 + 6.000\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
Model Parameters
| Parameter |
Value |
| H0 |
11.530 |
| n |
6.000 |
| gf |
0.994 |
| gb |
-0.863 |
| k |
0.997 |
| δ90 |
9.999 |
| 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
Finding Chart
Ephemeris
| Date/Time (UTC) |
RA (J2000) |
Dec (J2000) |
Nearest HIP |
Dist from HIP (arcmin) |
| 2026-09-20 00:00 |
04:10:27.93 |
+10:24:08.5 |
HIP 19359 |
24.45 |
| 2026-09-20 12:00 |
04:10:26.57 |
+10:22:49.1 |
HIP 19359 |
24.36 |
| 2026-09-21 00:00 |
04:10:24.96 |
+10:21:29.0 |
HIP 19359 |
24.29 |
| 2026-09-21 12:00 |
04:10:23.09 |
+10:20:08.2 |
HIP 19359 |
24.24 |
| 2026-09-22 00:00 |
04:10:20.97 |
+10:18:46.6 |
HIP 19359 |
24.22 |
| 2026-09-22 12:00 |
04:10:18.60 |
+10:17:24.3 |
HIP 19359 |
24.24 |
| 2026-09-23 00:00 |
04:10:15.97 |
+10:16:01.2 |
HIP 19359 |
24.30 |
| 2026-09-23 12:00 |
04:10:13.08 |
+10:14:37.4 |
HIP 19348 |
24.00 |
| 2026-09-24 00:00 |
04:10:09.94 |
+10:13:12.8 |
HIP 19348 |
22.80 |
| 2026-09-24 12:00 |
04:10:06.54 |
+10:11:47.6 |
HIP 19348 |
21.58 |
| 2026-09-25 00:00 |
04:10:02.88 |
+10:10:21.6 |
HIP 19348 |
20.36 |
| 2026-09-25 12:00 |
04:09:58.97 |
+10:08:54.9 |
HIP 19348 |
19.15 |
| 2026-09-26 00:00 |
04:09:54.79 |
+10:07:27.5 |
HIP 19348 |
17.95 |
| 2026-09-26 12:00 |
04:09:50.35 |
+10:05:59.4 |
HIP 19348 |
16.80 |
| 2026-09-27 00:00 |
04:09:45.66 |
+10:04:30.5 |
HIP 19348 |
15.71 |
| 2026-09-27 12:00 |
04:09:40.70 |
+10:03:01.0 |
HIP 19348 |
14.72 |
| 2026-09-28 00:00 |
04:09:35.47 |
+10:01:30.8 |
HIP 19348 |
13.87 |
| 2026-09-28 12:00 |
04:09:29.99 |
+10:00:00.0 |
HIP 19348 |
13.21 |
| 2026-09-29 00:00 |
04:09:24.24 |
+09:58:28.4 |
HIP 19348 |
12.80 |
| 2026-09-29 12:00 |
04:09:18.23 |
+09:56:56.1 |
HIP 19348 |
12.68 |
| 2026-09-30 00:00 |
04:09:11.95 |
+09:55:23.2 |
HIP 19348 |
12.88 |
| 2026-09-30 12:00 |
04:09:05.41 |
+09:53:49.6 |
HIP 19348 |
13.43 |
| 2026-10-01 00:00 |
04:08:58.60 |
+09:52:15.4 |
HIP 19348 |
14.30 |
| 2026-10-01 12:00 |
04:08:51.53 |
+09:50:40.5 |
HIP 19348 |
15.47 |
| 2026-10-02 00:00 |
04:08:44.19 |
+09:49:05.0 |
HIP 19348 |
16.89 |
| 2026-10-02 12:00 |
04:08:36.58 |
+09:47:28.8 |
HIP 19348 |
18.54 |
| 2026-10-03 00:00 |
04:08:28.70 |
+09:45:52.0 |
HIP 19257 |
20.26 |
| 2026-10-03 12:00 |
04:08:20.56 |
+09:44:14.6 |
HIP 19257 |
17.77 |
| 2026-10-04 00:00 |
04:08:12.15 |
+09:42:36.6 |
HIP 19257 |
15.26 |
| 2026-10-04 12:00 |
04:08:03.47 |
+09:40:58.0 |
HIP 19257 |
12.77 |
| 2026-10-05 00:00 |
04:07:54.52 |
+09:39:18.7 |
HIP 19257 |
10.35 |
| 2026-10-05 12:00 |
04:07:45.30 |
+09:37:38.9 |
HIP 19257 |
8.13 |
| 2026-10-06 00:00 |
04:07:35.81 |
+09:35:58.5 |
HIP 19257 |
6.39 |
| 2026-10-06 12:00 |
04:07:26.05 |
+09:34:17.5 |
HIP 19257 |
5.70 |
| 2026-10-07 00:00 |
04:07:16.03 |
+09:32:36.0 |
HIP 19257 |
6.49 |
| 2026-10-07 12:00 |
04:07:05.73 |
+09:30:53.9 |
HIP 19257 |
8.41 |
| 2026-10-08 00:00 |
04:06:55.17 |
+09:29:11.3 |
HIP 19257 |
10.93 |
| 2026-10-08 12:00 |
04:06:44.34 |
+09:27:28.1 |
HIP 19257 |
13.77 |
| 2026-10-09 00:00 |
04:06:33.24 |
+09:25:44.5 |
HIP 19257 |
16.79 |
| 2026-10-09 12:00 |
04:06:21.87 |
+09:24:00.3 |
HIP 19257 |
19.95 |
| 2026-10-10 00:00 |
04:06:10.24 |
+09:22:15.6 |
HIP 19257 |
23.21 |
| 2026-10-10 12:00 |
04:05:58.33 |
+09:20:30.4 |
HIP 19257 |
26.57 |
| 2026-10-11 00:00 |
04:05:46.17 |
+09:18:44.8 |
HIP 19257 |
30.00 |