| Parameter |
Value |
| Designation |
C/1999 F2 (Dalcanton) |
| Type |
C |
| Perihelion (tp_cal, UTC) |
1998-08-23T16:33:57.314880Z |
| Orbit solution date (soln_date, UTC) |
2021-04-15T23:29:57Z |
| Obs used |
137 |
| NEO |
- |
| M1 |
7.800 |
| K1 |
7.750 |
| PC |
0.030 |
Osculating Elements
| Parameter |
Value |
| Epoch (epoch_cal, TDB) |
1999-09-29.0000000 |
| e |
0.99821105 |
| q (au) |
4.718078 |
| a (au) |
2637.338054 |
| i (deg) |
56.427410 |
| Ω (om, deg) |
210.297746 |
| ω (w, deg) |
352.352637 |
| M (ma, deg) |
0.002920 |
Magnitude
Scatter + Global Linear
$$
M_a = (5.004 + 5.237\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
Model Parameters
| Parameter |
Value |
| H0 |
5.004 |
| n |
5.237 |
| gf |
0.998 |
| gb |
-0.608 |
| 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
Ephemeris
| Date/Time (UTC) |
RA (J2000) |
Dec (J2000) |
Nearest HIP |
Dist from HIP (arcmin) |
| 2026-03-26 00:00 |
23:04:08.32 |
+32:25:45.7 |
HIP 113898 |
5.06 |
| 2026-03-26 12:00 |
23:04:11.05 |
+32:26:03.3 |
HIP 113898 |
5.08 |
| 2026-03-27 00:00 |
23:04:13.78 |
+32:26:21.1 |
HIP 113898 |
5.17 |
| 2026-03-27 12:00 |
23:04:16.49 |
+32:26:39.0 |
HIP 113898 |
5.34 |
| 2026-03-28 00:00 |
23:04:19.20 |
+32:26:57.0 |
HIP 113898 |
5.57 |
| 2026-03-28 12:00 |
23:04:21.90 |
+32:27:15.2 |
HIP 113898 |
5.87 |
| 2026-03-29 00:00 |
23:04:24.59 |
+32:27:33.5 |
HIP 113898 |
6.21 |
| 2026-03-29 12:00 |
23:04:27.27 |
+32:27:52.0 |
HIP 113898 |
6.60 |
| 2026-03-30 00:00 |
23:04:29.94 |
+32:28:10.6 |
HIP 113898 |
7.02 |
| 2026-03-30 12:00 |
23:04:32.61 |
+32:28:29.3 |
HIP 113898 |
7.47 |
| 2026-03-31 00:00 |
23:04:35.26 |
+32:28:48.2 |
HIP 113898 |
7.95 |
| 2026-03-31 12:00 |
23:04:37.90 |
+32:29:07.2 |
HIP 113898 |
8.44 |
| 2026-04-01 00:00 |
23:04:40.54 |
+32:29:26.3 |
HIP 113898 |
8.95 |
| 2026-04-01 12:00 |
23:04:43.16 |
+32:29:45.6 |
HIP 113898 |
9.48 |
| 2026-04-02 00:00 |
23:04:45.77 |
+32:30:05.0 |
HIP 113898 |
10.01 |
| 2026-04-02 12:00 |
23:04:48.38 |
+32:30:24.5 |
HIP 113898 |
10.56 |
| 2026-04-03 00:00 |
23:04:50.97 |
+32:30:44.1 |
HIP 113898 |
11.11 |
| 2026-04-03 12:00 |
23:04:53.55 |
+32:31:03.9 |
HIP 113898 |
11.67 |
| 2026-04-04 00:00 |
23:04:56.13 |
+32:31:23.8 |
HIP 113898 |
12.23 |
| 2026-04-04 12:00 |
23:04:58.69 |
+32:31:43.8 |
HIP 113898 |
12.80 |
| 2026-04-05 00:00 |
23:05:01.24 |
+32:32:04.0 |
HIP 113898 |
13.38 |
| 2026-04-05 12:00 |
23:05:03.78 |
+32:32:24.3 |
HIP 113898 |
13.95 |
| 2026-04-06 00:00 |
23:05:06.30 |
+32:32:44.7 |
HIP 113898 |
14.53 |
| 2026-04-06 12:00 |
23:05:08.82 |
+32:33:05.2 |
HIP 113898 |
15.11 |
| 2026-04-07 00:00 |
23:05:11.32 |
+32:33:25.8 |
HIP 113898 |
15.69 |
| 2026-04-07 12:00 |
23:05:13.82 |
+32:33:46.5 |
HIP 113898 |
16.28 |
| 2026-04-08 00:00 |
23:05:16.30 |
+32:34:07.4 |
HIP 113898 |
16.86 |
| 2026-04-08 12:00 |
23:05:18.77 |
+32:34:28.3 |
HIP 113898 |
17.45 |
| 2026-04-09 00:00 |
23:05:21.22 |
+32:34:49.4 |
HIP 113898 |
18.04 |
| 2026-04-09 12:00 |
23:05:23.67 |
+32:35:10.6 |
HIP 113898 |
18.62 |
| 2026-04-10 00:00 |
23:05:26.10 |
+32:35:31.9 |
HIP 113898 |
19.21 |
| 2026-04-10 12:00 |
23:05:28.52 |
+32:35:53.3 |
HIP 113898 |
19.80 |
| 2026-04-11 00:00 |
23:05:30.92 |
+32:36:14.8 |
HIP 113898 |
20.39 |
| 2026-04-11 12:00 |
23:05:33.32 |
+32:36:36.4 |
HIP 113898 |
20.97 |
| 2026-04-12 00:00 |
23:05:35.70 |
+32:36:58.1 |
HIP 113898 |
21.56 |
| 2026-04-12 12:00 |
23:05:38.06 |
+32:37:19.9 |
HIP 113898 |
22.15 |
| 2026-04-13 00:00 |
23:05:40.42 |
+32:37:41.8 |
HIP 113898 |
22.73 |
| 2026-04-13 12:00 |
23:05:42.75 |
+32:38:03.8 |
HIP 113898 |
23.32 |
| 2026-04-14 00:00 |
23:05:45.08 |
+32:38:26.0 |
HIP 113898 |
23.90 |
| 2026-04-14 12:00 |
23:05:47.39 |
+32:38:48.1 |
HIP 114187 |
23.67 |
| 2026-04-15 00:00 |
23:05:49.69 |
+32:39:10.4 |
HIP 114187 |
23.07 |
| 2026-04-15 12:00 |
23:05:51.97 |
+32:39:32.8 |
HIP 114187 |
22.47 |
| 2026-04-16 00:00 |
23:05:54.24 |
+32:39:55.3 |
HIP 114187 |
21.88 |