| Parameter |
Value |
| Designation |
113P/Spitaler |
| Type |
P |
| Perihelion (tp_cal, UTC) |
2015-04-23T18:19:34.599360Z |
| Orbit solution date (soln_date, UTC) |
2024-04-29T13:12:26Z |
| Obs used |
879 |
| NEO |
- |
| M1 |
14.700 |
| K1 |
8.000 |
| PC |
- |
Osculating Elements
| Parameter |
Value |
| Epoch (epoch_cal, TDB) |
2015-07-26.0000000 |
| e |
0.42451621 |
| q (au) |
2.118865 |
| a (au) |
3.681885 |
| i (deg) |
5.776267 |
| Ω (om, deg) |
14.385093 |
| ω (w, deg) |
50.026650 |
| M (ma, deg) |
13.007213 |
Magnitude
Scatter + Global Linear
$$
M_a = (10.379 + 6.000\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
Model Parameters
| Parameter |
Value |
| H0 |
10.379 |
| n |
6.000 |
| gf |
1.000 |
| gb |
-0.854 |
| k |
0.999 |
| 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 |
| 2021-06-18 |
2022-06-01 |
+1.1076 |
-0.529 |
| 2022-06-01 |
2023-04-15 |
+5.3352 |
-1.919 |
log10 r = log10(heliocentric distance / AU), Δ = geocentric distance (AU)
Ephemeris
| Date/Time (UTC) |
RA (J2000) |
Dec (J2000) |
Nearest HIP |
Dist from HIP (arcmin) |
| 2026-05-12 00:00 |
16:57:33.22 |
-27:59:10.7 |
HIP 82878 |
18.32 |
| 2026-05-12 12:00 |
16:57:15.86 |
-27:58:54.2 |
HIP 82878 |
14.95 |
| 2026-05-13 00:00 |
16:56:58.36 |
-27:58:37.0 |
HIP 82878 |
11.87 |
| 2026-05-13 12:00 |
16:56:40.73 |
-27:58:19.3 |
HIP 82878 |
9.38 |
| 2026-05-14 00:00 |
16:56:22.96 |
-27:58:00.9 |
HIP 82878 |
8.09 |
| 2026-05-14 12:00 |
16:56:05.07 |
-27:57:41.9 |
HIP 82878 |
8.62 |
| 2026-05-15 00:00 |
16:55:47.05 |
-27:57:22.3 |
HIP 82878 |
10.72 |
| 2026-05-15 12:00 |
16:55:28.90 |
-27:57:02.1 |
HIP 82878 |
13.72 |
| 2026-05-16 00:00 |
16:55:10.64 |
-27:56:41.2 |
HIP 82754 |
12.66 |
| 2026-05-16 12:00 |
16:54:52.26 |
-27:56:19.7 |
HIP 82754 |
11.43 |
| 2026-05-17 00:00 |
16:54:33.76 |
-27:55:57.6 |
HIP 82754 |
11.59 |
| 2026-05-17 12:00 |
16:54:15.15 |
-27:55:34.8 |
HIP 82697 |
11.31 |
| 2026-05-18 00:00 |
16:53:56.44 |
-27:55:11.5 |
HIP 82697 |
12.39 |
| 2026-05-18 12:00 |
16:53:37.61 |
-27:54:47.5 |
HIP 82697 |
14.64 |
| 2026-05-19 00:00 |
16:53:18.69 |
-27:54:22.9 |
HIP 82697 |
17.63 |
| 2026-05-19 12:00 |
16:52:59.67 |
-27:53:57.7 |
HIP 82697 |
21.05 |
| 2026-05-20 00:00 |
16:52:40.55 |
-27:53:31.8 |
HIP 82479 |
18.43 |
| 2026-05-20 12:00 |
16:52:21.34 |
-27:53:05.3 |
HIP 82479 |
14.94 |
| 2026-05-21 00:00 |
16:52:02.03 |
-27:52:38.2 |
HIP 82479 |
11.94 |
| 2026-05-21 12:00 |
16:51:42.65 |
-27:52:10.5 |
HIP 82479 |
9.95 |
| 2026-05-22 00:00 |
16:51:23.18 |
-27:51:42.1 |
HIP 82458 |
8.09 |
| 2026-05-22 12:00 |
16:51:03.63 |
-27:51:13.2 |
HIP 82458 |
7.59 |
| 2026-05-23 00:00 |
16:50:44.00 |
-27:50:43.6 |
HIP 82458 |
9.37 |
| 2026-05-23 12:00 |
16:50:24.30 |
-27:50:13.4 |
HIP 82458 |
12.51 |
| 2026-05-24 00:00 |
16:50:04.53 |
-27:49:42.6 |
HIP 82458 |
16.26 |
| 2026-05-24 12:00 |
16:49:44.69 |
-27:49:11.2 |
HIP 82330 |
15.60 |
| 2026-05-25 00:00 |
16:49:24.79 |
-27:48:39.2 |
HIP 82330 |
14.26 |
| 2026-05-25 12:00 |
16:49:04.83 |
-27:48:06.6 |
HIP 82315 |
13.88 |
| 2026-05-26 00:00 |
16:48:44.81 |
-27:47:33.3 |
HIP 82315 |
14.27 |
| 2026-05-26 12:00 |
16:48:24.74 |
-27:46:59.5 |
HIP 82315 |
15.96 |
| 2026-05-27 00:00 |
16:48:04.62 |
-27:46:25.1 |
HIP 82315 |
18.59 |
| 2026-05-27 12:00 |
16:47:44.45 |
-27:45:50.1 |
HIP 82315 |
21.85 |
| 2026-05-28 00:00 |
16:47:24.23 |
-27:45:14.5 |
HIP 82315 |
25.49 |
| 2026-05-28 12:00 |
16:47:03.97 |
-27:44:38.3 |
HIP 82008 |
27.62 |
| 2026-05-29 00:00 |
16:46:43.68 |
-27:44:01.5 |
HIP 82008 |
23.83 |
| 2026-05-29 12:00 |
16:46:23.35 |
-27:43:24.1 |
HIP 82008 |
20.35 |
| 2026-05-30 00:00 |
16:46:02.99 |
-27:42:46.2 |
HIP 82008 |
17.37 |
| 2026-05-30 12:00 |
16:45:42.60 |
-27:42:07.7 |
HIP 82008 |
15.18 |
| 2026-05-31 00:00 |
16:45:22.18 |
-27:41:28.6 |
HIP 82008 |
14.18 |
| 2026-05-31 12:00 |
16:45:01.74 |
-27:40:49.0 |
HIP 81981 |
13.71 |
| 2026-06-01 00:00 |
16:44:41.28 |
-27:40:08.8 |
HIP 81981 |
12.92 |
| 2026-06-01 12:00 |
16:44:20.81 |
-27:39:28.0 |
HIP 81939 |
12.12 |
| 2026-06-02 00:00 |
16:44:00.33 |
-27:38:46.7 |
HIP 81939 |
12.02 |