| Parameter |
Value |
| Designation |
8P/Tuttle |
| Type |
P |
| Perihelion (tp_cal, UTC) |
2008-01-27T00:25:56.539200Z |
| Orbit solution date (soln_date, UTC) |
2022-05-02T08:47:13Z |
| Obs used |
1768 |
| NEO |
Yes |
| M1 |
14.600 |
| K1 |
4.500 |
| PC |
- |
Osculating Elements
| Parameter |
Value |
| Epoch (epoch_cal, TDB) |
2008-08-23.0000000 |
| e |
0.81978762 |
| q (au) |
1.027263 |
| a (au) |
5.700291 |
| i (deg) |
54.981969 |
| Ω (om, deg) |
270.342162 |
| ω (w, deg) |
207.511518 |
| M (ma, deg) |
15.134474 |
Magnitude
Scatter + Global Linear
$$
M_a = (10.014 + 5.507\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
Model Parameters
| Parameter |
Value |
| H0 |
10.014 |
| n |
5.507 |
| gf |
0.998 |
| gb |
-1.000 |
| k |
0.996 |
| 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 |
| 2020-06-21 |
2021-10-15 |
-14.7328 |
-0.879 |
| 2021-10-15 |
2021-08-27 |
+8.0581 |
-2.802 |
| 2021-08-27 |
2022-03-19 |
-2.3685 |
+0.975 |
log10 r = log10(heliocentric distance / AU), Δ = geocentric distance (AU)
Ephemeris
| Date/Time (UTC) |
RA (J2000) |
Dec (J2000) |
Nearest HIP |
Dist from HIP (arcmin) |
| 2026-03-26 00:00 |
19:02:57.68 |
-09:07:54.6 |
HIP 93504 |
13.43 |
| 2026-03-26 12:00 |
19:03:00.61 |
-09:06:47.3 |
HIP 93504 |
12.75 |
| 2026-03-27 00:00 |
19:03:03.43 |
-09:05:40.0 |
HIP 93504 |
12.16 |
| 2026-03-27 12:00 |
19:03:06.16 |
-09:04:32.7 |
HIP 93504 |
11.68 |
| 2026-03-28 00:00 |
19:03:08.79 |
-09:03:25.4 |
HIP 93504 |
11.32 |
| 2026-03-28 12:00 |
19:03:11.31 |
-09:02:18.1 |
HIP 93504 |
11.07 |
| 2026-03-29 00:00 |
19:03:13.73 |
-09:01:10.9 |
HIP 93504 |
10.95 |
| 2026-03-29 12:00 |
19:03:16.05 |
-09:00:03.6 |
HIP 93504 |
10.95 |
| 2026-03-30 00:00 |
19:03:18.27 |
-08:58:56.4 |
HIP 93504 |
11.07 |
| 2026-03-30 12:00 |
19:03:20.39 |
-08:57:49.3 |
HIP 93504 |
11.31 |
| 2026-03-31 00:00 |
19:03:22.41 |
-08:56:42.1 |
HIP 93504 |
11.64 |
| 2026-03-31 12:00 |
19:03:24.32 |
-08:55:35.0 |
HIP 93504 |
12.07 |
| 2026-04-01 00:00 |
19:03:26.13 |
-08:54:27.9 |
HIP 93504 |
12.57 |
| 2026-04-01 12:00 |
19:03:27.84 |
-08:53:20.9 |
HIP 93504 |
13.14 |
| 2026-04-02 00:00 |
19:03:29.45 |
-08:52:13.9 |
HIP 93504 |
13.77 |
| 2026-04-02 12:00 |
19:03:30.95 |
-08:51:07.0 |
HIP 93504 |
14.44 |
| 2026-04-03 00:00 |
19:03:32.35 |
-08:50:00.1 |
HIP 93504 |
15.15 |
| 2026-04-03 12:00 |
19:03:33.64 |
-08:48:53.2 |
HIP 93504 |
15.89 |
| 2026-04-04 00:00 |
19:03:34.84 |
-08:47:46.5 |
HIP 93504 |
16.65 |
| 2026-04-04 12:00 |
19:03:35.92 |
-08:46:39.7 |
HIP 93504 |
17.44 |
| 2026-04-05 00:00 |
19:03:36.91 |
-08:45:33.1 |
HIP 93504 |
18.24 |
| 2026-04-05 12:00 |
19:03:37.79 |
-08:44:26.5 |
HIP 93702 |
18.60 |
| 2026-04-06 00:00 |
19:03:38.56 |
-08:43:19.9 |
HIP 93702 |
18.12 |
| 2026-04-06 12:00 |
19:03:39.23 |
-08:42:13.5 |
HIP 93702 |
17.73 |
| 2026-04-07 00:00 |
19:03:39.79 |
-08:41:07.1 |
HIP 93702 |
17.43 |
| 2026-04-07 12:00 |
19:03:40.25 |
-08:40:00.8 |
HIP 93702 |
17.23 |
| 2026-04-08 00:00 |
19:03:40.60 |
-08:38:54.6 |
HIP 93702 |
17.11 |
| 2026-04-08 12:00 |
19:03:40.85 |
-08:37:48.4 |
HIP 93702 |
17.10 |
| 2026-04-09 00:00 |
19:03:40.99 |
-08:36:42.4 |
HIP 93702 |
17.18 |
| 2026-04-09 12:00 |
19:03:41.02 |
-08:35:36.4 |
HIP 93702 |
17.36 |
| 2026-04-10 00:00 |
19:03:40.95 |
-08:34:30.5 |
HIP 93702 |
17.63 |
| 2026-04-10 12:00 |
19:03:40.77 |
-08:33:24.8 |
HIP 93702 |
17.99 |
| 2026-04-11 00:00 |
19:03:40.49 |
-08:32:19.1 |
HIP 93702 |
18.43 |
| 2026-04-11 12:00 |
19:03:40.10 |
-08:31:13.5 |
HIP 93702 |
18.94 |
| 2026-04-12 00:00 |
19:03:39.60 |
-08:30:08.1 |
HIP 93702 |
19.53 |
| 2026-04-12 12:00 |
19:03:38.99 |
-08:29:02.8 |
HIP 93702 |
20.18 |
| 2026-04-13 00:00 |
19:03:38.28 |
-08:27:57.6 |
HIP 93702 |
20.89 |
| 2026-04-13 12:00 |
19:03:37.45 |
-08:26:52.5 |
HIP 93702 |
21.66 |
| 2026-04-14 00:00 |
19:03:36.53 |
-08:25:47.5 |
HIP 93702 |
22.47 |
| 2026-04-14 12:00 |
19:03:35.49 |
-08:24:42.6 |
HIP 93702 |
23.33 |
| 2026-04-15 00:00 |
19:03:34.34 |
-08:23:37.9 |
HIP 93702 |
24.22 |
| 2026-04-15 12:00 |
19:03:33.09 |
-08:22:33.4 |
HIP 93702 |
25.16 |
| 2026-04-16 00:00 |
19:03:31.73 |
-08:21:28.9 |
HIP 93709 |
24.87 |