Please report here any bug found on this version as comment to this post. I’ll do the same.
I#0018 - EQT View : The choice of the star names is erroneously linked to the flag of the HOR View. SOLVED. I#0019 - AZM View: deleted a "ghost line" from constellation lines. F#0022 - EQT View: Top left infos about the tracked object now show Equatorial Coordinates. F#0023 - EQTView: added selectable precision for crosshair coordinates. F#0024 - Added asteroids with visual magnitude <= 14 managed by means of "astorb.dat".
Hi
I just downloaded the latest version 0.9.9.216R.
There are many interesting improvements.
So far, no bug detected.
The blue color is a good choice and the grouping of hours (UTC…) on the same side of the map is more readable. I noticed the warning window for dates between 5 and 14 october 1582.
Keep the good work.
Best regards
Hi
When Galileo pointed his telescope in the night of 7 January 1610, he saw for the first time in human history that moons orbited Jupiter. From Padua (45° 25′ 00″ N, 11° 52′ 00″ E), he observed Io (J1), Europa (J2), Ganymede (J3) and Callisto (J4) during the night of 13 January 1610 (see https://solarsystem.nasa.gov/news/307/galileos-observations-of-the-moon-jupiter-venus-and-the-sun/). Uruk_One, from Padua, at 16:50 UT (sunset 15:54 UT), is in good accordance with Galileo’s sketch of Jupiter’s Moons.
Regards
The most interesting fact is that Galileo occasionally observed Neptune on December 1612 and February 1613 from Florence, marking its position but, as he wrote, classifying it as a “fixa” (fixed star). Probably due to bad weather Galileo missed a transit of Jupiter over Neptune on Jan 4, 1613. Just for curiosity, at that time hours were counted from noon but Galileo frequently uses “ab oc[casu soli]” (after sunset) to indicate the time of his observations.
Hi
Stonehenge (51°10′44″N 1°49′34″W) was constructed from 3000 BC to 2000 BC. It is interesting to check the apparent topocentric AD and DE of the Full Moon with refraction, on 29 January 2000 BC (-1999) 0:00 UT. Using JPL HORIZONS with DE431, AD = 7h 8m 31.35s and DE =+25° 18′ 16.7″ . Using Uruk-One, AD = 7h 8m 28.06s and DE = +25° 17′ 52.67″. Good results, I suppose the discrepancy comes from delta T algorithms in use.
By the way, I notice in the Ephemeris window: nutazione instead of nutation, for me it is not clear in the table Geocentric and Topocentric Equatorial coordinates – True Equinox of Date which column is related to TA and OA. When I select tracking Moon for instance and Horizontal view, on the left I can read the altazimuth coordinates, but when I switch to equatorial view I still read the altazimuth coordinates. Is there a way to read also the equatorial coordinates?
On my PC, the Sun appears in its window on the right on a blue/red sky when rising and setting but on a black background as soon as H > 02° 21′. Is it on purpose? In older version, the background was blue.
Thank you for your hard work and your answers.
Regards
Hi Bercu,
comparison of coordinates should be always done in TDT just to avoid discrepancies due to DeltaT. In this case, trying to match with UTC time we have:
Horizons : RA = 07h 08m 31.35s DC = +25° 18′ 16.7″
Solex 12.1: RA = 07h 08m 21.83s. DC = +25° 17′ 53.4″
UrukOne : RA = 07h 08m 22.05s. DC = +25° 17′ 55.97″
In this case I wonder what does Horizons mean for “Apparent Topocentric”. All the mentioned programs are using DE431 but Horizon’s position looks too far away from others.
– Nutazion instead of Nutation. It’s a mixed form of Italian and English. 🙂 Ok, a mistype, I will correct that.
– I can’t get what you mean here. The Table Geocentric and Topocentric Equatorial Coordinates is not related with OA e TA, which are horizontal coordinates. OA and TA are related each other (refraction and horizon depression due to observer’s altitude over the sea level) and are derived by topocentric apparent RA/DEC only.
– Ok, the EQT view could show the equatorial coordinates of the tracked object (ICRS and/or EOD). Going to add them
– Yes, I decided to show the Sun on a black BG, as you should see it in your telescope with a solar filter on. Maybe I should remove the sunrise and sunset lights that do not suit this representation of the solar disk.
Thanks
Alberto Cavalli
Hi
Thank you very much for your answer:
You are right: comparison of coordinates should be done in TDT. However it is not always possible to use TDT instead of UT when using other software.
This time, using TDT, I compare UrukOne with HORIZONS and IMCCE (French Institute for Celestial Mechanics and Computation of Ephemerides, Paris Observatory) which uses its own ephemeris INPOP17. For instance, I compute apparent RA & DE for the Moon on 20 October 2020, 00:00:00 TDT, location Paris Observatory.
INPOP : http://vo.imcce.fr/webservices/miriade/?forms
Using HORIZONS: RA = 16h 39m 45.86s & DE = -21° 51′ 42.4″
Using UrukOne : RA = 16h 39m 45.86s & DE = -21° 51′ 42.34″
Using INPOP17: RA = 16h 39m 45.85s & DE = -21° 51′ 42.42″
UrukOne, HORIZONS and INPOP17 yield same results. Great job !
Regarding the Table of Geocentric and Topocentric equatorial coordinates : sorry, my mistake.
Your decision to show the Sun on a black BG is OK. I was afraid the black BG was due to my graphic card.
Regards
I’ve been following since years with great interest the IMCCE (formerly Bureau des Longitudes) works. French astronomers have a long tradition in Celestial Mechanics (Bretagnon, Francou, Chapront, his wife Mme Chapront-Touzè, Laskar, Capitaine, and many others). From the late 80’s until last year I used VSOP and ELP ephemerides and only the huge time span of the DE431 convinced me to switch to JPL ephemerides.
I had the opportunity to meet many times Nicole Capitaine and Jacques Laskar : lectures at the French Académie des Sciences, at Paris Observatory…
Jacques Laskar try to correlate planetary ephemerides with geology data : an interesting paper in English can be found at https://www.imcce.fr/news/mouvements-planetaires-geologie (toggle Fr/En). Of course I am not suggesting UrukOne should compute in a future version ephemerides at the time of dinosaurs…
Reference about INPOP19a (IMCCE’s latest ephemeris) can be found also in English at https://www.imcce.fr/recherche/equipes/asd/inpop/ (toggle Fr/En)
All the best