| 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) |
| 2026-07-29 00:00 |
16:15:53.66 |
-25:57:31.7 |
HIP 79771 |
14.04 |
| 2026-07-29 12:00 |
16:15:49.09 |
-25:56:47.8 |
HIP 79771 |
14.72 |
| 2026-07-30 00:00 |
16:15:44.73 |
-25:56:04.4 |
HIP 79771 |
15.43 |
| 2026-07-30 12:00 |
16:15:40.60 |
-25:55:21.4 |
HIP 79771 |
16.15 |
| 2026-07-31 00:00 |
16:15:36.68 |
-25:54:39.0 |
HIP 79771 |
16.88 |
| 2026-07-31 12:00 |
16:15:32.98 |
-25:53:57.0 |
HIP 79771 |
17.60 |
| 2026-08-01 00:00 |
16:15:29.49 |
-25:53:15.5 |
HIP 79771 |
18.31 |
| 2026-08-01 12:00 |
16:15:26.23 |
-25:52:34.4 |
HIP 79771 |
19.00 |
| 2026-08-02 00:00 |
16:15:23.18 |
-25:51:53.9 |
HIP 79771 |
19.67 |
| 2026-08-02 12:00 |
16:15:20.34 |
-25:51:13.9 |
HIP 79771 |
20.32 |
| 2026-08-03 00:00 |
16:15:17.72 |
-25:50:34.3 |
HIP 79771 |
20.94 |
| 2026-08-03 12:00 |
16:15:15.32 |
-25:49:55.3 |
HIP 79771 |
21.52 |
| 2026-08-04 00:00 |
16:15:13.14 |
-25:49:16.8 |
HIP 79622 |
21.14 |
| 2026-08-04 12:00 |
16:15:11.17 |
-25:48:38.7 |
HIP 79622 |
20.43 |
| 2026-08-05 00:00 |
16:15:09.42 |
-25:48:01.2 |
HIP 79622 |
19.74 |
| 2026-08-05 12:00 |
16:15:07.89 |
-25:47:24.2 |
HIP 79622 |
19.07 |
| 2026-08-06 00:00 |
16:15:06.57 |
-25:46:47.8 |
HIP 79622 |
18.42 |
| 2026-08-06 12:00 |
16:15:05.47 |
-25:46:11.8 |
HIP 79622 |
17.79 |
| 2026-08-07 00:00 |
16:15:04.59 |
-25:45:36.4 |
HIP 79622 |
17.18 |
| 2026-08-07 12:00 |
16:15:03.92 |
-25:45:01.5 |
HIP 79622 |
16.58 |
| 2026-08-08 00:00 |
16:15:03.47 |
-25:44:27.1 |
HIP 79622 |
16.00 |
| 2026-08-08 12:00 |
16:15:03.23 |
-25:43:53.2 |
HIP 79622 |
15.43 |
| 2026-08-09 00:00 |
16:15:03.21 |
-25:43:19.9 |
HIP 79622 |
14.88 |
| 2026-08-09 12:00 |
16:15:03.41 |
-25:42:47.1 |
HIP 79622 |
14.35 |
| 2026-08-10 00:00 |
16:15:03.82 |
-25:42:14.9 |
HIP 79622 |
13.83 |
| 2026-08-10 12:00 |
16:15:04.45 |
-25:41:43.2 |
HIP 79622 |
13.34 |
| 2026-08-11 00:00 |
16:15:05.29 |
-25:41:12.0 |
HIP 79622 |
12.87 |
| 2026-08-11 12:00 |
16:15:06.35 |
-25:40:41.4 |
HIP 79622 |
12.42 |
| 2026-08-12 00:00 |
16:15:07.63 |
-25:40:11.3 |
HIP 79622 |
12.01 |
| 2026-08-12 12:00 |
16:15:09.11 |
-25:39:41.8 |
HIP 79622 |
11.63 |
| 2026-08-13 00:00 |
16:15:10.82 |
-25:39:12.8 |
HIP 79622 |
11.30 |
| 2026-08-13 12:00 |
16:15:12.73 |
-25:38:44.4 |
HIP 79622 |
11.02 |
| 2026-08-14 00:00 |
16:15:14.86 |
-25:38:16.5 |
HIP 79622 |
10.80 |
| 2026-08-14 12:00 |
16:15:17.20 |
-25:37:49.2 |
HIP 79622 |
10.65 |
| 2026-08-15 00:00 |
16:15:19.76 |
-25:37:22.4 |
HIP 79622 |
10.58 |
| 2026-08-15 12:00 |
16:15:22.52 |
-25:36:56.1 |
HIP 79622 |
10.60 |
| 2026-08-16 00:00 |
16:15:25.50 |
-25:36:30.4 |
HIP 79622 |
10.70 |
| 2026-08-16 12:00 |
16:15:28.68 |
-25:36:05.3 |
HIP 79622 |
10.91 |
| 2026-08-17 00:00 |
16:15:32.08 |
-25:35:40.7 |
HIP 79622 |
11.22 |
| 2026-08-17 12:00 |
16:15:35.69 |
-25:35:16.6 |
HIP 79622 |
11.63 |
| 2026-08-18 00:00 |
16:15:39.50 |
-25:34:53.1 |
HIP 79622 |
12.14 |
| 2026-08-18 12:00 |
16:15:43.52 |
-25:34:30.1 |
HIP 79622 |
12.74 |
| 2026-08-19 00:00 |
16:15:47.75 |
-25:34:07.7 |
HIP 79622 |
13.44 |