Finding solar position and velocity vectors for a JD

I'd like to find the six pieces of data in Subject for JD 435400.82885.
I think there are tables for these elements. Are they available on the
web or use some computation to find them?

On 2011-09-28, W. eWatson wrote:

I'd like to find the six pieces of data in Subject for JD 435400.82885.
I think there are tables for these elements. Are they available on the
web or use some computation to find them?

Jean Meeus' Astronomical Algorithms (Willmann-Bell) probably is the
source for this. What happens on January 24, 3521, at 7:53:33 in the
morning, UTC?

Bud

On 9/27/2011 10:09 PM, William Hamblen wrote:
On 2011-09-28, W. wrote:

I'd like to find the six pieces of data in Subject for JD 435400.82885.
I think there are tables for these elements. Are they available on the
web or use some computation to find them?

Jean Meeus' Astronomical Algorithms (Willmann-Bell) probably is the
source for this. What happens on January 24, 3521, at 7:53:33 in the
morning, UTC?

Bud

A meteor entered the earth's atmosphere. Something looks awry in your
calculation. These should be the elements for the earth, and it doesn't
look like Meeus calculates them. He gives the typical e, L, etc.

W. eWatson wrote:
I'd like to find the six pieces of data in Subject for JD
435400.82885. I think there are tables for these elements. Are they
available on the web or use some computation to find them?

US Naval Observatory mentions software marketed through Willmann-Bell called
MICA. This may have what you need for the postiion vectors as these
quantities are tabulated in the Astronomical Almanac.

http://aa.usno.navy.mil/software/

I don't think they give velocity vector components. However, I could be
wrong about that. There is a free software called "rv" which runs under
linux (I do not know of a windows version but maybe) and which is used to
compute velocity corrections for barycentric reductions. It may or may not
also have a capability of giving velocity components.

Years and years ago, I used interpolation formulae to calculate the first
derivative of the vector components from the tabulated position values, in
order to get the rv correction accurately from the tabulated X,Y,Z of the
Sun.

--
Mike Dworetsky

(Remove pants sp*mbl*ck to reply)

On 2011-09-28, W. eWatson wrote:
On 9/27/2011 10:09 PM, William Hamblen wrote:
On 2011-09-28, W. wrote:

I'd like to find the six pieces of data in Subject for JD 435400.82885.
I think there are tables for these elements. Are they available on the
web or use some computation to find them?

Jean Meeus' Astronomical Algorithms (Willmann-Bell) probably is the
source for this. What happens on January 24, 3521, at 7:53:33 in the
morning, UTC?

Bud

A meteor entered the earth's atmosphere. Something looks awry in your
calculation. These should be the elements for the earth, and it doesn't
look like Meeus calculates them. He gives the typical e, L, etc.

I left the minus sign off the date. Sorry.

2011 September 28 is JD 2455833 so JD 435400.82885 is in the distant
past.

Bud

On 9/28/2011 10:43 AM, William Hamblen wrote:
On 2011-09-28, W. wrote:
On 9/27/2011 10:09 PM, William Hamblen wrote:
On 2011-09-28, W. wrote:

I'd like to find the six pieces of data in Subject for JD 435400.82885.
I think there are tables for these elements. Are they available on the
web or use some computation to find them?

Jean Meeus' Astronomical Algorithms (Willmann-Bell) probably is the
source for this. What happens on January 24, 3521, at 7:53:33 in the
morning, UTC?

Bud

A meteor entered the earth's atmosphere. Something looks awry in your
calculation. These should be the elements for the earth, and it doesn't
look like Meeus calculates them. He gives the typical e, L, etc.

I left the minus sign off the date. Sorry.

2011 September 28 is JD 2455833 so JD 435400.82885 is in the distant
past.

Bud
I would expect it to be earlier than 1967.

On 9/28/2011 9:13 AM, Mike Dworetsky wrote:
W. eWatson wrote:
I'd like to find the six pieces of data in Subject for JD
435400.82885. I think there are tables for these elements. Are they
available on the web or use some computation to find them?

US Naval Observatory mentions software marketed through Willmann-Bell
called MICA. This may have what you need for the postiion vectors as
these quantities are tabulated in the Astronomical Almanac.

http://aa.usno.navy.mil/software/

I don't think they give velocity vector components. However, I could be
wrong about that. There is a free software called "rv" which runs under
linux (I do not know of a windows version but maybe) and which is used
to compute velocity corrections for barycentric reductions. It may or
may not also have a capability of giving velocity components.

Years and years ago, I used interpolation formulae to calculate the
first derivative of the vector components from the tabulated position
values, in order to get the rv correction accurately from the tabulated
X,Y,Z of the Sun.

As it turns out, I only need the data for one instance of time, so
buying nautical almanacs, etc. is pretty much out of the question.

Yes, you are on the right track with respect to interpolation formula,
but to get started, I need the data (L, e, etc., I think) for that
specific time. It then becomes a matter of interpolating several days in
either direction to get the vectors.

Ah, I have a friend who is solar astronomer. Maybe he can just look it up.

In article ,
"W. eWatson" writes:
I'd like to find the six pieces of data in Subject for JD 435400.82885.

"Horizons" system:
http://ssd.jpl.nasa.gov/?horizons

--
Help keep our newsgroup healthy; please don't feed the trolls.
Steve Willner Phone 617-495-7123
Cambridge, MA 02138 USA

In sci.astro message , Wed, 28 Sep 2011
12:14:24, W. eWatson posted:

On 9/28/2011 10:43 AM, William Hamblen wrote:

2011 September 28 is JD 2455833 so JD 435400.82885 is in the distant
past.


I would expect it to be earlier than 1967.


You're right, but inexact - Google easily finds
http://aa.usno.navy.mil/data/docs/JulianDate.php which told me

JD 435400.828850 is BCE 3521 January 24 07:53:32.6 UT Tuesday

and that will be on the Proleptic Julian Calendar.

I make it Tue, 26 Dec -3521 Proleptic Astronomical Gregorian.

--
(c) John Stockton, nr London, UK. Turnpike v6.05.
Website http://www.merlyn.demon.co.uk/ - w. FAQish topics, links, acronyms
PAS EXE etc. : http://www.merlyn.demon.co.uk/programs/ - see in 00index.htm
Dates - miscdate.htm estrdate.htm js-dates.htm pas-time.htm critdate.htm etc.

On 2011-09-29, Dr J R Stockton wrote:
In sci.astro message , Wed, 28 Sep 2011
12:14:24, W. eWatson posted:

On 9/28/2011 10:43 AM, William Hamblen wrote:

2011 September 28 is JD 2455833 so JD 435400.82885 is in the distant
past.


I would expect it to be earlier than 1967.


You're right, but inexact - Google easily finds
http://aa.usno.navy.mil/data/docs/JulianDate.php which told me

JD 435400.828850 is BCE 3521 January 24 07:53:32.6 UT Tuesday

and that will be on the Proleptic Julian Calendar.

I make it Tue, 26 Dec -3521 Proleptic Astronomical Gregorian.


See a few articles further up the thread.

In any case, the date is outside the range of JPL's Horizons. The date
also is probably not what eWatson intended, as he claims there was
supposed to be a meteor observation on the date. JD 2435400.828850
probably was what was wanted. That's just a guess.

Bud