Determination orbital elements of the comets

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Josef
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Joined: Sun Sep 08, 2019 12:25 pm

Determination orbital elements of the comets

Post by Josef »

Finally I finished program for determination orbital elements of the comets from three position. I took partially algorithms from Jean-Marc Baillard, with his kind permission. I searched the internet for a long time for a program to calculate orbital parameters, but unsuccessfully. There is one simple web app (not very accurate), but I was not satisfied with the results. My program ORBIT calculates path elements very well.

You have three dates and positions RA and DEC. Program ORBIT will compute rectangular ecliptic coordinates of the Sun and comet, from that compute complete orbits elements of Comet P2007/T2 Kowalski, for example:


DATE- 1: 2007/07/01 0h # DATE-2: 2007/07/05 0h # DATE-3: 2007/07/09 0h
RA-1: 14h27m25s57 # RA-2: 14h16m33s94 # RA-3: 14h06m37s72
DE-1: -39°30'56"18 # DE-2: -38°44'07"32 # DE-3: -37°52'59"14

Run program : XEQ "ORBIT"

Put in all data to DATE, RA and DE (always push R/S). After that you can see complete input data, number of days form 1.1.2000 and computed rectangular ecliptic coordinates of the Sun X and Y for a check. Push R/S and you can see complete Orbital Elements of the comet. If you want print your put in data again run XEQ "PRT1", If you want print Orbital Elements again run XEQ "PRT". If you have thermal printer HP82240B, you can print it (set PON in PRINT menu).

You can reduce the ecliptic elements from one equinox to another one with routine "CORR". Clear flag F00 for the transformation J2000 >> Equinox T or Set flag F00 for the transformation Equinox T >> J2000. In this case is it from 2007 to 2000 or invert. Now run XEQ "CORR", choose "1" for agree with recompute, R/S and you can see new elements.

Program is using very nice and useful routine DISPLAY and FONTS from user Bill (Smithville NJ) for print to LCD.

You can download program HERE.

Below you can see Orbital Elements from authority JPL (NASA) and from calculator, I think it!s very good result, when we realize that we use 14 years old coordinates of the comet.

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Snímek obrazovky 2021-03-03 v 17.56.04.png
Snímek obrazovky 2021-03-03 v 17.56.04.png (232.47 KiB) Viewed 2917 times
Orbit_DM42-4.jpg
Orbit_DM42-4.jpg (78.51 KiB) Viewed 2917 times
HP printer.jpg
HP printer.jpg (96.91 KiB) Viewed 2917 times
rprosperi
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Location: New York

Re: Determination orbital elements of the comets

Post by rprosperi »

The link to download the .zip file does not work...
--bob p

DM42: β00071 & 00282, DM41X: β00071 & 00656, DM10L: 071/100
Josef
Posts: 24
Joined: Sun Sep 08, 2019 12:25 pm

Re: Determination orbital elements of the comets

Post by Josef »

Sorry, now is OK, thank you!
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salvomic
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Re: Determination orbital elements of the comets

Post by salvomic »

thanks, very interesting.

Salvo
∫aL√0mic (IT9CLU) :: DM42 (SN: 00881), DM41X (SN 00523), DM16, HP Prime, 50g, 41CX, 42s, 71b, 15C, 12C, 35s, WP34s -- Free42
Josef
Posts: 24
Joined: Sun Sep 08, 2019 12:25 pm

Re: Determination orbital elements of the comets

Post by Josef »

Thank you salvomic!

I finished second program, a continuation of the program for determination orbital elements of the comets. Now you can compute RA, DEC and delta (distance between comet and earth in AU) for next dates and times from orbital elements. Yes, the calculation has limited accuracy, but it's still interesting.

Run INPUT, DAT-C is date of computing position (format DD.MMYYYY), DAT-T is time of perihelion (format DD.MMYYYY).

For example, comet 10P/Tempel 2:

Time for computing: 16.3.2021
T (Time of perihelion passage) : 5.7.2010 (2455382.2881)
q (perihelion distance) : 1.421805958451013
e (eccentricity) : 0.5362731523679858
i (inclination) : 12.02422299818989
peri (Argument of perihelion ω) : 195.6077883346506
node (Longitude of ascending node Ω) : 117.8023017705041

You can download all subroutines from here:
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Last edited by Josef on Thu Mar 18, 2021 7:34 am, edited 1 time in total.
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salvomic
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Re: Determination orbital elements of the comets

Post by salvomic »

very nice also this one, Josef, thank you.

Salvo
∫aL√0mic (IT9CLU) :: DM42 (SN: 00881), DM41X (SN 00523), DM16, HP Prime, 50g, 41CX, 42s, 71b, 15C, 12C, 35s, WP34s -- Free42
Josef
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Re: Determination orbital elements of the comets

Post by Josef »

Thank you!

I tested also on this comet C/2019 L3 Atlas from JPL orbit elements:

JPL__________: 2021-Mar-16 00:00 RA 01 51 45.3 DEC +51 29 35.7 delta 4.865018
Calculator__ : 2021-Mar-16 00:00 RA 01 53 09.3 DEC +51 36 05.6 delta 4.864787
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salvomic
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Re: Determination orbital elements of the comets

Post by salvomic »

Josef wrote:
Wed Mar 17, 2021 9:32 pm
I tested also on this comet C/2019 L3 Atlas from JPL orbit elements:

JPL__________: 2021-Mar-16 00:00 RA 01 51 45.3 DEC +51 29 35.7 delta 4.865018
Calculator__ : 2021-Mar-16 00:00 RA 01 53 09.3 DEC +51 36 05.6 delta 4.864787
A good approximation, indeed.
∫aL√0mic (IT9CLU) :: DM42 (SN: 00881), DM41X (SN 00523), DM16, HP Prime, 50g, 41CX, 42s, 71b, 15C, 12C, 35s, WP34s -- Free42
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