Guest guest Posted July 22, 2009 Report Share Posted July 22, 2009 Dear Mr.Narasimha P.V.R. Rao, Few months ago I had posted to this group, asking for clarification on eclipse and full moon - no moon calculations. I would like one more clarification regarding today's eclipse. I was watching the eclipse on television and on my laptop (using Starry Night planetarium software). Even though I was in the path of totality, due to rain, I was unable to witness the event in the sky. In many parts of India, the totality occurred at 6.22 a.m. (I.S.T.) Even the city I am staying was plunged into darkness. This means, at this moment, the centers of the Sun and the Moon were perfectly aligned. Using my planetarium software following were the sayan positions of sun and moon: Sun 119.377° Moon 119.361° The minor difference in fractional part can be neglected because I had rounded off the time. Using Jagannath Hora V. 7.32, following values were obtained Sun 119.380° Moon 118.361° Why is the moon's position offset by 1° ? In that case totality would not have been possible. Two other Astrology softwares which I use gave similar results. The Panchang I use is one of the first Panchang to adopt modern methods of calculations. The results were Sun 119.341° Moon 117.821° Why is the moon's position wrong (?) in each case? If this is really an error in astrological calculations, then it could make a deep impact on predictions which we make. My settings are as follows Date 22-July 2009 Time 6 hrs 22 min (I.S.T., G.M.T. +5:30) Location Anand (Gujarat State, India) Lat : 22°34'N Long 72°56'E Ayanamsha : Sayan The positions of Sun and Moon are represented in Decimal format (thus if sun's position was 119.75°, it could have meant 119°45' --- this is to avoid ambiguity) Regards, Kedar Damle Quote Link to comment Share on other sites More sharing options...
Guest guest Posted July 22, 2009 Report Share Posted July 22, 2009 Namaste, In Jyotisha, we use true geocentric positions. But, if you want to time a visual effect such as an eclipse, use apparent topocentric positions instead of true geocentric positions. True vs apparent makes very little difference, but geocentric vs topocentric makes a big difference for Moon. If I use apparent topocentric positions, sayana longitude of Sun at 6:22 am at Anand, India is 29 Cn 22' 34.86 " and Moon at 29 Cn 21' 45.17 " . This matches your planetarium software. Your planetarium software must be giving apparent topocentric positions. After all, a planetarium software will look at the sky from the current place and not from the center of earth. Best regards, Narasimha ---- kedar damle <damkedar wrote: > Dear Mr.Narasimha P.V.R. Rao, > > Few months ago I had posted to this group, asking for clarification on > eclipse and full moon - no moon calculations. > I would like one more clarification regarding today's eclipse. I was > watching the eclipse on television and on my laptop (using Starry Night > planetarium software). Even though I was in the path of totality, due to > rain, I was unable to witness the event in the sky. > In many parts of India, the totality occurred at 6.22 a.m. (I.S.T.) Even > the city I am staying was plunged into darkness. > This means, at this moment, the centers of the Sun and the Moon were > perfectly aligned. > Using my planetarium software following were the sayan positions of sun > and moon: > > Sun 119.377° Moon 119.361° > The minor difference in fractional part can be neglected because I had > rounded off the time. > > Using Jagannath Hora V. 7.32, following values were obtained > > Sun 119.380° Moon 118.361° > > Why is the moon's position offset by 1° ? In that case totality would > not have been possible. > Two other Astrology softwares which I use gave similar results. > The Panchang I use is one of the first Panchang to adopt modern methods > of calculations. The results were > > Sun 119.341° Moon 117.821° > > Why is the moon's position wrong (?) in each case? > If this is really an error in astrological calculations, then it could > make a deep impact on predictions which we make. > > My settings are as follows > Date 22-July 2009 > Time 6 hrs 22 min (I.S.T., G.M.T. +5:30) > Location Anand (Gujarat State, India) > Lat : 22°34'N > Long 72°56'E > Ayanamsha : Sayan > The positions of Sun and Moon are represented in Decimal format (thus if > sun's position was 119.75°, it could have meant 119°45' --- this is to > avoid ambiguity) > > Regards, > Kedar Damle Quote Link to comment Share on other sites More sharing options...
Guest guest Posted July 23, 2009 Report Share Posted July 23, 2009 Dear Narasimha PVR Rao, Thanks for your quick reply. My confusion has been solved. I will now try to find out the equations for converting topocentric co-ordinates to geocentric co-ordinates. Regards, Kedar Damle Narasimha PVR Rao wrote: Namaste, In Jyotisha, we use true geocentric positions. But, if you want to time a visual effect such as an eclipse, use apparent topocentric positions instead of true geocentric positions. True vs apparent makes very little difference, but geocentric vs topocentric makes a big difference for Moon. If I use apparent topocentric positions, sayana longitude of Sun at 6:22 am at Anand, India is 29 Cn 22' 34.86" and Moon at 29 Cn 21' 45.17". This matches your planetarium software. Your planetarium software must be giving apparent topocentric positions. After all, a planetarium software will look at the sky from the current place and not from the center of earth. Best regards, Narasimha ---- kedar damle <damkedar wrote: Dear Mr.Narasimha P.V.R. Rao, Few months ago I had posted to this group, asking for clarification on eclipse and full moon - no moon calculations. I would like one more clarification regarding today's eclipse. I was watching the eclipse on television and on my laptop (using Starry Night planetarium software). Even though I was in the path of totality, due to rain, I was unable to witness the event in the sky. In many parts of India, the totality occurred at 6.22 a.m. (I.S.T.) Even the city I am staying was plunged into darkness. This means, at this moment, the centers of the Sun and the Moon were perfectly aligned. Using my planetarium software following were the sayan positions of sun and moon: Sun 119.377° Moon 119.361° The minor difference in fractional part can be neglected because I had rounded off the time. Using Jagannath Hora V. 7.32, following values were obtained Sun 119.380° Moon 118.361° Why is the moon's position offset by 1° ? In that case totality would not have been possible. Two other Astrology softwares which I use gave similar results. The Panchang I use is one of the first Panchang to adopt modern methods of calculations. The results were Sun 119.341° Moon 117.821° Why is the moon's position wrong (?) in each case? If this is really an error in astrological calculations, then it could make a deep impact on predictions which we make. My settings are as follows Date 22-July 2009 Time 6 hrs 22 min (I.S.T., G.M.T. +5:30) Location Anand (Gujarat State, India) Lat : 22°34'N Long 72°56'E Ayanamsha : Sayan The positions of Sun and Moon are represented in Decimal format (thus if sun's position was 119.75°, it could have meant 119°45' --- this is to avoid ambiguity) Regards, Kedar Damle Quote Link to comment Share on other sites More sharing options...
Guest guest Posted July 23, 2009 Report Share Posted July 23, 2009 --- On Thu, 23/7/09, kedar damle <damkedar wrote:kedar damle <damkedarRe: Calculation of Sun and Moon"Narasimha PVR Rao" <pvr, jhora Date: Thursday, 23 July, 2009, 6:30 AM Dear Narasimha PVR Rao, Thanks for your quick reply. My confusion has been solved. I will now try to find out the equations for converting topocentric co-ordinates to geocentric co-ordinates. Regards, Kedar Damle Narasimha PVR Rao wrote: Namaste, In Jyotisha, we use true geocentric positions. But, if you want to time a visual effect such as an eclipse, use apparent topocentric positions instead of true geocentric positions. True vs apparent makes very little difference, but geocentric vs topocentric makes a big difference for Moon. If I use apparent topocentric positions, sayana longitude of Sun at 6:22 am at Anand, India is 29 Cn 22' 34.86" and Moon at 29 Cn 21' 45.17". This matches your planetarium software. Your planetarium software must be giving apparent topocentric positions. After all, a planetarium software will look at the sky from the current place and not from the center of earth. Best regards,Narasimha ---- kedar damle <damkedar (AT) gmail (DOT) com> wrote: Dear Mr.Narasimha P.V.R. Rao,Few months ago I had posted to this group, asking for clarification on eclipse and full moon - no moon calculations.I would like one more clarification regarding today's eclipse. I was watching the eclipse on television and on my laptop (using Starry Night planetarium software). Even though I was in the path of totality, due to rain, I was unable to witness the event in the sky.In many parts of India, the totality occurred at 6.22 a.m. (I.S.T.) Even the city I am staying was plunged into darkness.This means, at this moment, the centers of the Sun and the Moon were perfectly aligned.Using my planetarium software following were the sayan positions of sun and moon:Sun 119.377° Moon 119.361° The minor difference in fractional part can be neglected because I had rounded off the time.Using Jagannath Hora V. 7.32, following values were obtainedSun 119.380° Moon 118.361°Why is the moon's position offset by 1° ? In that case totality would not have been possible.Two other Astrology softwares which I use gave similar results.The Panchang I use is one of the first Panchang to adopt modern methods of calculations. The results wereSun 119.341° Moon 117.821°Why is the moon's position wrong (?) in each case?If this is really an error in astrological calculations, then it could make a deep impact on predictions which we make.My settings are as followsDate 22-July 2009Time 6 hrs 22 min (I.S.T., G.M.T. +5:30)Location Anand (Gujarat State, India)Lat : 22°34'NLong 72°56'EAyanamsha : SayanThe positions of Sun and Moon are represented in Decimal format (thus if sun's position was 119.75°, it could have meant 119°45' --- this is to avoid ambiguity)Regards,Kedar Damle See the Web's breaking stories, chosen by people like you. Check out Buzz. Quote Link to comment Share on other sites More sharing options...
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