| Parameter |
Value |
| Designation |
C/2014 Y1 (PANSTARRS) |
| Type |
C |
| Perihelion (tp_cal, UTC) |
2016-01-17T15:41:20.803200Z |
| Orbit solution date (soln_date, UTC) |
2021-04-15T23:33:05Z |
| Obs used |
305 |
| NEO |
- |
| M1 |
12.800 |
| K1 |
4.500 |
| PC |
- |
Osculating Elements
| Parameter |
Value |
| Epoch (epoch_cal, TDB) |
2015-04-19.0000000 |
| e |
1.00210330 |
| q (au) |
2.240976 |
| a (au) |
-1065.459229 |
| i (deg) |
14.921289 |
| Ω (om, deg) |
19.516424 |
| ω (w, deg) |
182.265969 |
| M (ma, deg) |
-0.007755 |
Magnitude
Scatter + Global Linear
$$
M_a = (15.038 + 2.000\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
Model Parameters
| Parameter |
Value |
| H0 |
15.038 |
| n |
2.000 |
| gf |
1.000 |
| gb |
-0.719 |
| 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 |
| 2014-11-17 |
2015-04-22 |
+9.9842 |
-6.474 |
| 2015-04-22 |
2016-01-10 |
-0.5262 |
-0.311 |
| 2016-01-19 |
2016-05-29 |
+16.0710 |
-4.516 |
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 |
23:33:54.61 |
-11:48:11.6 |
HIP 116233 |
17.53 |
| 2026-07-29 12:00 |
23:33:51.82 |
-11:48:35.6 |
HIP 116233 |
16.75 |
| 2026-07-30 00:00 |
23:33:49.01 |
-11:48:59.6 |
HIP 116233 |
15.97 |
| 2026-07-30 12:00 |
23:33:46.16 |
-11:49:23.8 |
HIP 116233 |
15.17 |
| 2026-07-31 00:00 |
23:33:43.29 |
-11:49:48.1 |
HIP 116233 |
14.38 |
| 2026-07-31 12:00 |
23:33:40.38 |
-11:50:12.4 |
HIP 116233 |
13.58 |
| 2026-08-01 00:00 |
23:33:37.45 |
-11:50:36.9 |
HIP 116233 |
12.77 |
| 2026-08-01 12:00 |
23:33:34.50 |
-11:51:01.5 |
HIP 116233 |
11.96 |
| 2026-08-02 00:00 |
23:33:31.51 |
-11:51:26.2 |
HIP 116233 |
11.15 |
| 2026-08-02 12:00 |
23:33:28.50 |
-11:51:51.0 |
HIP 116233 |
10.34 |
| 2026-08-03 00:00 |
23:33:25.46 |
-11:52:15.9 |
HIP 116233 |
9.53 |
| 2026-08-03 12:00 |
23:33:22.39 |
-11:52:40.9 |
HIP 116233 |
8.71 |
| 2026-08-04 00:00 |
23:33:19.30 |
-11:53:06.0 |
HIP 116233 |
7.91 |
| 2026-08-04 12:00 |
23:33:16.18 |
-11:53:31.1 |
HIP 116233 |
7.11 |
| 2026-08-05 00:00 |
23:33:13.04 |
-11:53:56.4 |
HIP 116233 |
6.33 |
| 2026-08-05 12:00 |
23:33:09.87 |
-11:54:21.7 |
HIP 116233 |
5.57 |
| 2026-08-06 00:00 |
23:33:06.67 |
-11:54:47.2 |
HIP 116233 |
4.85 |
| 2026-08-06 12:00 |
23:33:03.45 |
-11:55:12.7 |
HIP 116233 |
4.19 |
| 2026-08-07 00:00 |
23:33:00.20 |
-11:55:38.3 |
HIP 116233 |
3.63 |
| 2026-08-07 12:00 |
23:32:56.93 |
-11:56:03.9 |
HIP 116233 |
3.23 |
| 2026-08-08 00:00 |
23:32:53.63 |
-11:56:29.7 |
HIP 116233 |
3.06 |
| 2026-08-08 12:00 |
23:32:50.31 |
-11:56:55.5 |
HIP 116233 |
3.15 |
| 2026-08-09 00:00 |
23:32:46.97 |
-11:57:21.4 |
HIP 116233 |
3.50 |
| 2026-08-09 12:00 |
23:32:43.60 |
-11:57:47.3 |
HIP 116233 |
4.04 |
| 2026-08-10 00:00 |
23:32:40.21 |
-11:58:13.4 |
HIP 116233 |
4.71 |
| 2026-08-10 12:00 |
23:32:36.79 |
-11:58:39.5 |
HIP 116233 |
5.46 |
| 2026-08-11 00:00 |
23:32:33.35 |
-11:59:05.6 |
HIP 116233 |
6.27 |
| 2026-08-11 12:00 |
23:32:29.89 |
-11:59:31.8 |
HIP 116233 |
7.12 |
| 2026-08-12 00:00 |
23:32:26.41 |
-11:59:58.1 |
HIP 116233 |
8.00 |
| 2026-08-12 12:00 |
23:32:22.90 |
-12:00:24.4 |
HIP 116128 |
8.55 |
| 2026-08-13 00:00 |
23:32:19.37 |
-12:00:50.8 |
HIP 116128 |
7.98 |
| 2026-08-13 12:00 |
23:32:15.82 |
-12:01:17.2 |
HIP 116128 |
7.49 |
| 2026-08-14 00:00 |
23:32:12.25 |
-12:01:43.7 |
HIP 116128 |
7.10 |
| 2026-08-14 12:00 |
23:32:08.66 |
-12:02:10.2 |
HIP 116128 |
6.82 |
| 2026-08-15 00:00 |
23:32:05.05 |
-12:02:36.8 |
HIP 116128 |
6.68 |
| 2026-08-15 12:00 |
23:32:01.41 |
-12:03:03.4 |
HIP 116128 |
6.67 |
| 2026-08-16 00:00 |
23:31:57.76 |
-12:03:30.0 |
HIP 116128 |
6.82 |
| 2026-08-16 12:00 |
23:31:54.09 |
-12:03:56.6 |
HIP 116128 |
7.10 |
| 2026-08-17 00:00 |
23:31:50.40 |
-12:04:23.3 |
HIP 116128 |
7.51 |
| 2026-08-17 12:00 |
23:31:46.69 |
-12:04:50.1 |
HIP 116128 |
8.02 |
| 2026-08-18 00:00 |
23:31:42.96 |
-12:05:16.8 |
HIP 116128 |
8.63 |
| 2026-08-18 12:00 |
23:31:39.21 |
-12:05:43.6 |
HIP 116078 |
8.01 |
| 2026-08-19 00:00 |
23:31:35.45 |
-12:06:10.4 |
HIP 116078 |
7.08 |