C/1999 F2 (Dalcanton)
| 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) |
| 2026-02-03 00:00 |
22:59:20.51 |
+32:12:05.1 |
HIP 113633 |
26.32 |
| 2026-02-03 12:00 |
22:59:23.09 |
+32:12:02.4 |
HIP 113633 |
25.97 |
| 2026-02-04 00:00 |
22:59:25.69 |
+32:12:00.0 |
HIP 113633 |
25.62 |
| 2026-02-04 12:00 |
22:59:28.29 |
+32:11:57.8 |
HIP 113633 |
25.28 |
| 2026-02-05 00:00 |
22:59:30.91 |
+32:11:55.8 |
HIP 113633 |
24.93 |
| 2026-02-05 12:00 |
22:59:33.53 |
+32:11:54.0 |
HIP 113633 |
24.60 |
| 2026-02-06 00:00 |
22:59:36.17 |
+32:11:52.5 |
HIP 113633 |
24.26 |
| 2026-02-06 12:00 |
22:59:38.81 |
+32:11:51.2 |
HIP 113633 |
23.93 |
| 2026-02-07 00:00 |
22:59:41.47 |
+32:11:50.1 |
HIP 113633 |
23.60 |
| 2026-02-07 12:00 |
22:59:44.13 |
+32:11:49.2 |
HIP 113633 |
23.28 |
| 2026-02-08 00:00 |
22:59:46.81 |
+32:11:48.6 |
HIP 113633 |
22.97 |
| 2026-02-08 12:00 |
22:59:49.49 |
+32:11:48.2 |
HIP 113633 |
22.66 |
| 2026-02-09 00:00 |
22:59:52.18 |
+32:11:48.0 |
HIP 113633 |
22.35 |
| 2026-02-09 12:00 |
22:59:54.89 |
+32:11:48.0 |
HIP 113633 |
22.05 |
| 2026-02-10 00:00 |
22:59:57.60 |
+32:11:48.3 |
HIP 113633 |
21.76 |
| 2026-02-10 12:00 |
23:00:00.32 |
+32:11:48.8 |
HIP 113633 |
21.47 |
| 2026-02-11 00:00 |
23:00:03.05 |
+32:11:49.5 |
HIP 113633 |
21.20 |
| 2026-02-11 12:00 |
23:00:05.78 |
+32:11:50.4 |
HIP 113633 |
20.93 |
| 2026-02-12 00:00 |
23:00:08.53 |
+32:11:51.6 |
HIP 113633 |
20.67 |
| 2026-02-12 12:00 |
23:00:11.28 |
+32:11:53.0 |
HIP 113633 |
20.41 |
| 2026-02-13 00:00 |
23:00:14.04 |
+32:11:54.6 |
HIP 113633 |
20.17 |
| 2026-02-13 12:00 |
23:00:16.81 |
+32:11:56.4 |
HIP 113633 |
19.94 |
| 2026-02-14 00:00 |
23:00:19.59 |
+32:11:58.5 |
HIP 113633 |
19.72 |
| 2026-02-14 12:00 |
23:00:22.37 |
+32:12:00.8 |
HIP 113633 |
19.51 |
| 2026-02-15 00:00 |
23:00:25.16 |
+32:12:03.3 |
HIP 113633 |
19.31 |
| 2026-02-15 12:00 |
23:00:27.96 |
+32:12:06.0 |
HIP 113633 |
19.12 |
| 2026-02-16 00:00 |
23:00:30.76 |
+32:12:08.9 |
HIP 113633 |
18.95 |
| 2026-02-16 12:00 |
23:00:33.57 |
+32:12:12.1 |
HIP 113633 |
18.79 |
| 2026-02-17 00:00 |
23:00:36.39 |
+32:12:15.5 |
HIP 113633 |
18.64 |
| 2026-02-17 12:00 |
23:00:39.21 |
+32:12:19.1 |
HIP 113633 |
18.51 |
| 2026-02-18 00:00 |
23:00:42.04 |
+32:12:22.9 |
HIP 113633 |
18.39 |
| 2026-02-18 12:00 |
23:00:44.87 |
+32:12:27.0 |
HIP 113633 |
18.29 |
| 2026-02-19 00:00 |
23:00:47.71 |
+32:12:31.2 |
HIP 113633 |
18.20 |
| 2026-02-19 12:00 |
23:00:50.55 |
+32:12:35.7 |
HIP 113633 |
18.13 |
| 2026-02-20 00:00 |
23:00:53.40 |
+32:12:40.4 |
HIP 113633 |
18.08 |
| 2026-02-20 12:00 |
23:00:56.26 |
+32:12:45.4 |
HIP 113633 |
18.04 |
| 2026-02-21 00:00 |
23:00:59.11 |
+32:12:50.5 |
HIP 113633 |
18.02 |
| 2026-02-21 12:00 |
23:01:01.98 |
+32:12:55.9 |
HIP 113633 |
18.02 |
| 2026-02-22 00:00 |
23:01:04.84 |
+32:13:01.4 |
HIP 113633 |
18.03 |
| 2026-02-22 12:00 |
23:01:07.72 |
+32:13:07.2 |
HIP 113633 |
18.06 |
| 2026-02-23 00:00 |
23:01:10.59 |
+32:13:13.2 |
HIP 113633 |
18.11 |
| 2026-02-23 12:00 |
23:01:13.47 |
+32:13:19.4 |
HIP 113633 |
18.18 |
| 2026-02-24 00:00 |
23:01:16.35 |
+32:13:25.8 |
HIP 113633 |
18.27 |