| Parameter |
Value |
| Designation |
273P/Pons-Gambart |
| Type |
P |
| Perihelion (tp_cal, UTC) |
2012-12-19T16:06:04.144320Z |
| Orbit solution date (soln_date, UTC) |
2021-04-15T23:28:12Z |
| Obs used |
1140 |
| NEO |
Yes |
| M1 |
11.300 |
| K1 |
8.750 |
| PC |
0.030 |
Osculating Elements
| Parameter |
Value |
| Epoch (epoch_cal, TDB) |
2013-03-18.0000000 |
| e |
0.97532437 |
| q (au) |
0.810159 |
| a (au) |
32.832346 |
| i (deg) |
136.396031 |
| Ω (om, deg) |
320.431172 |
| ω (w, deg) |
20.191912 |
| M (ma, deg) |
0.462759 |
Magnitude
Scatter + Global Linear
$$
M_a = (12.697 + 5.779\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
Model Parameters
| Parameter |
Value |
| H0 |
12.697 |
| n |
5.779 |
| gf |
1.000 |
| gb |
-0.949 |
| 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
Residuals (Piecewise)
$$\epsilon = a \log_{10} r_{\mathrm{au}} + b$$
| Start (UTC) |
End (UTC) |
a |
b |
| 2012-12-22 |
2013-01-27 |
-8.2349 |
-1.482 |
| 2013-01-27 |
2013-02-11 |
+1.7959 |
-1.599 |
| 2013-02-11 |
2013-03-04 |
+15.9199 |
-2.714 |
| 2013-03-04 |
2013-04-29 |
+2.7105 |
-0.831 |
| 2013-04-29 |
2014-04-04 |
-2.5470 |
+0.557 |
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 |
09:03:14.57 |
+13:00:30.1 |
HIP 44581 |
32.26 |
| 2026-05-12 12:00 |
09:03:14.93 |
+13:00:30.6 |
HIP 44581 |
32.19 |
| 2026-05-13 00:00 |
09:03:15.33 |
+13:00:30.9 |
HIP 44581 |
32.11 |
| 2026-05-13 12:00 |
09:03:15.76 |
+13:00:31.1 |
HIP 44581 |
32.02 |
| 2026-05-14 00:00 |
09:03:16.23 |
+13:00:31.2 |
HIP 44581 |
31.94 |
| 2026-05-14 12:00 |
09:03:16.73 |
+13:00:31.0 |
HIP 44581 |
31.84 |
| 2026-05-15 00:00 |
09:03:17.26 |
+13:00:30.7 |
HIP 44581 |
31.74 |
| 2026-05-15 12:00 |
09:03:17.83 |
+13:00:30.3 |
HIP 44581 |
31.64 |
| 2026-05-16 00:00 |
09:03:18.44 |
+13:00:29.7 |
HIP 44581 |
31.54 |
| 2026-05-16 12:00 |
09:03:19.08 |
+13:00:28.9 |
HIP 44581 |
31.42 |
| 2026-05-17 00:00 |
09:03:19.75 |
+13:00:28.0 |
HIP 44581 |
31.31 |
| 2026-05-17 12:00 |
09:03:20.46 |
+13:00:26.9 |
HIP 44581 |
31.19 |
| 2026-05-18 00:00 |
09:03:21.20 |
+13:00:25.7 |
HIP 44581 |
31.06 |
| 2026-05-18 12:00 |
09:03:21.98 |
+13:00:24.3 |
HIP 44581 |
30.94 |
| 2026-05-19 00:00 |
09:03:22.79 |
+13:00:22.7 |
HIP 44581 |
30.80 |
| 2026-05-19 12:00 |
09:03:23.63 |
+13:00:21.0 |
HIP 44581 |
30.67 |
| 2026-05-20 00:00 |
09:03:24.51 |
+13:00:19.2 |
HIP 44581 |
30.53 |
| 2026-05-20 12:00 |
09:03:25.41 |
+13:00:17.2 |
HIP 44581 |
30.39 |
| 2026-05-21 00:00 |
09:03:26.36 |
+13:00:15.0 |
HIP 44581 |
30.24 |
| 2026-05-21 12:00 |
09:03:27.33 |
+13:00:12.7 |
HIP 44581 |
30.09 |
| 2026-05-22 00:00 |
09:03:28.34 |
+13:00:10.2 |
HIP 44581 |
29.94 |
| 2026-05-22 12:00 |
09:03:29.38 |
+13:00:07.5 |
HIP 44581 |
29.79 |
| 2026-05-23 00:00 |
09:03:30.46 |
+13:00:04.7 |
HIP 44581 |
29.63 |
| 2026-05-23 12:00 |
09:03:31.56 |
+13:00:01.8 |
HIP 44581 |
29.47 |
| 2026-05-24 00:00 |
09:03:32.70 |
+12:59:58.7 |
HIP 44581 |
29.31 |
| 2026-05-24 12:00 |
09:03:33.87 |
+12:59:55.4 |
HIP 44581 |
29.15 |
| 2026-05-25 00:00 |
09:03:35.07 |
+12:59:52.0 |
HIP 44581 |
28.98 |
| 2026-05-25 12:00 |
09:03:36.31 |
+12:59:48.5 |
HIP 44581 |
28.82 |
| 2026-05-26 00:00 |
09:03:37.58 |
+12:59:44.8 |
HIP 44581 |
28.65 |
| 2026-05-26 12:00 |
09:03:38.87 |
+12:59:40.9 |
HIP 44581 |
28.48 |
| 2026-05-27 00:00 |
09:03:40.20 |
+12:59:36.9 |
HIP 44581 |
28.31 |
| 2026-05-27 12:00 |
09:03:41.56 |
+12:59:32.7 |
HIP 44581 |
28.15 |
| 2026-05-28 00:00 |
09:03:42.95 |
+12:59:28.4 |
HIP 44581 |
27.98 |
| 2026-05-28 12:00 |
09:03:44.38 |
+12:59:24.0 |
HIP 44581 |
27.81 |
| 2026-05-29 00:00 |
09:03:45.83 |
+12:59:19.4 |
HIP 44581 |
27.64 |
| 2026-05-29 12:00 |
09:03:47.31 |
+12:59:14.6 |
HIP 44581 |
27.47 |
| 2026-05-30 00:00 |
09:03:48.83 |
+12:59:09.7 |
HIP 44581 |
27.31 |
| 2026-05-30 12:00 |
09:03:50.37 |
+12:59:04.6 |
HIP 44581 |
27.15 |
| 2026-05-31 00:00 |
09:03:51.94 |
+12:58:59.4 |
HIP 44581 |
26.98 |
| 2026-05-31 12:00 |
09:03:53.55 |
+12:58:54.1 |
HIP 44581 |
26.82 |
| 2026-06-01 00:00 |
09:03:55.18 |
+12:58:48.6 |
HIP 44581 |
26.67 |
| 2026-06-01 12:00 |
09:03:56.85 |
+12:58:43.0 |
HIP 44581 |
26.52 |
| 2026-06-02 00:00 |
09:03:58.54 |
+12:58:37.2 |
HIP 44581 |
26.37 |