메타데이터

항목	값
Designation	177P/Barnard
Type	P
Perihelion (tp_cal, UTC)	2006-08-28T16:23:52.091520Z
Orbit solution date (soln_date, UTC)	2021-04-15T23:27:46Z
Obs used	1702
NEO	Yes
M1	15.700
K1	13.000
PC	0.030

Osculating 궤도요소

항목	값
Epoch (epoch_cal, TDB)	2006-04-24.0000000
e	0.95444204
q (au)	1.107271
a (au)	24.304669
i (deg)	31.216459
Ω (om, deg)	272.067721
ω (w, deg)	60.453551
M (ma, deg)	358.957950

밝기

산란 + 전체 선형

$$ M_a = (15.195 + 4.041\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta $$ $$ \theta = 180^\circ - \alpha $$ $$ \Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b) $$ $$ \Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1 $$

모델 상수

항목	값
H0	15.195
n	4.041
gf	1.000
gb	-0.500
k	1.000
δ90	10.000

파라미터	기호	범위	설명
태양·지구거리 1 AU에서의 절대등급	H0	-5 to 20	혜성의 고유 밝기
광도 기울기 파라미터	n	2 to 6	태양거리 변화에 따른 밝기 변화율
전방 산란 비대칭 계수	gf	0.8 to 1	전방 산란의 강도
후방 산란 비대칭 계수	gb	-1 to -0.5	후방 산란의 강도
분할 계수	k	0.8 to 1	전·후방 산란 기여도 비율
먼지/가스 밝기 비	δ90	1 to 10	코마에서 먼지 산란 대비 가스 방출의 상대 기여

참고: EPSC-DPS2025-160

잔차 (구간 선형)

$$\epsilon = a \log_{10} r_{\mathrm{au}} + b$$

시작일 (UTC)	끝 (UTC)	a	b
2006-06-23	2006-08-28	+13.5160	-2.197
2006-08-28	2006-11-01	-5.2733	-2.545
2006-11-01	2006-12-11	+35.3909	-8.724

log10 r = log10(태양거리/AU), Δ = 지구거리(AU)

천체력

Date/Time (UTC)	RA (J2000)	Dec (J2000)	Nearest HIP	Dist from HIP (arcmin)
2026-07-29 00:00	08:47:00.51	-05:04:53.5	HIP 43284	31.99
2026-07-29 12:00	08:47:03.99	-05:05:06.6	HIP 43284	31.10
2026-07-30 00:00	08:47:07.48	-05:05:19.9	HIP 43284	30.21
2026-07-30 12:00	08:47:10.96	-05:05:33.4	HIP 43284	29.31
2026-07-31 00:00	08:47:14.44	-05:05:47.0	HIP 43284	28.42
2026-07-31 12:00	08:47:17.93	-05:06:00.8	HIP 43284	27.52
2026-08-01 00:00	08:47:21.41	-05:06:14.8	HIP 43284	26.62
2026-08-01 12:00	08:47:24.89	-05:06:29.0	HIP 43284	25.72
2026-08-02 00:00	08:47:28.38	-05:06:43.3	HIP 43284	24.82
2026-08-02 12:00	08:47:31.86	-05:06:57.8	HIP 43284	23.92
2026-08-03 00:00	08:47:35.35	-05:07:12.5	HIP 43284	23.02
2026-08-03 12:00	08:47:38.83	-05:07:27.3	HIP 43284	22.12
2026-08-04 00:00	08:47:42.31	-05:07:42.3	HIP 43284	21.22
2026-08-04 12:00	08:47:45.79	-05:07:57.5	HIP 43284	20.32
2026-08-05 00:00	08:47:49.27	-05:08:12.9	HIP 43284	19.42
2026-08-05 12:00	08:47:52.75	-05:08:28.4	HIP 43284	18.51
2026-08-06 00:00	08:47:56.23	-05:08:44.0	HIP 43284	17.61
2026-08-06 12:00	08:47:59.70	-05:08:59.9	HIP 43284	16.70
2026-08-07 00:00	08:48:03.18	-05:09:15.8	HIP 43284	15.80
2026-08-07 12:00	08:48:06.65	-05:09:32.0	HIP 43284	14.90
2026-08-08 00:00	08:48:10.11	-05:09:48.3	HIP 43284	13.99
2026-08-08 12:00	08:48:13.58	-05:10:04.8	HIP 43284	13.09
2026-08-09 00:00	08:48:17.04	-05:10:21.4	HIP 43284	12.18
2026-08-09 12:00	08:48:20.50	-05:10:38.2	HIP 43284	11.28
2026-08-10 00:00	08:48:23.95	-05:10:55.2	HIP 43284	10.37
2026-08-10 12:00	08:48:27.41	-05:11:12.3	HIP 43284	9.46
2026-08-11 00:00	08:48:30.85	-05:11:29.6	HIP 43284	8.56
2026-08-11 12:00	08:48:34.30	-05:11:47.0	HIP 43284	7.65
2026-08-12 00:00	08:48:37.74	-05:12:04.6	HIP 43284	6.75
2026-08-12 12:00	08:48:41.17	-05:12:22.3	HIP 43284	5.85
2026-08-13 00:00	08:48:44.60	-05:12:40.2	HIP 43284	4.94
2026-08-13 12:00	08:48:48.02	-05:12:58.2	HIP 43284	4.04
2026-08-14 00:00	08:48:51.44	-05:13:16.4	HIP 43284	3.13
2026-08-14 12:00	08:48:54.86	-05:13:34.7	HIP 43284	2.23
2026-08-15 00:00	08:48:58.26	-05:13:53.2	HIP 43284	1.33
2026-08-15 12:00	08:49:01.66	-05:14:11.8	HIP 43284	0.43
2026-08-16 00:00	08:49:05.06	-05:14:30.6	HIP 43284	0.48
2026-08-16 12:00	08:49:08.45	-05:14:49.5	HIP 43284	1.38
2026-08-17 00:00	08:49:11.83	-05:15:08.5	HIP 43284	2.27
2026-08-17 12:00	08:49:15.20	-05:15:27.7	HIP 43284	3.17
2026-08-18 00:00	08:49:18.57	-05:15:47.0	HIP 43284	4.07
2026-08-18 12:00	08:49:21.93	-05:16:06.5	HIP 43284	4.97
2026-08-19 00:00	08:49:25.28	-05:16:26.1	HIP 43284	5.86