Recent content by JeffOCA

Ok, the picture link I posted is taken at visible wavelengths that why dust material is not bright. Am I right ? Regards JF

Hello, When you look at the accretion disk around NGC 4261 (see here), you can read that the dark, dusty disk represents a cold outer region which extends inwards to an ultra-hot accretion disk with a few hundred million miles from the suspected black hole. So, from the outside, you have...

This analemma (where I see an ellipse for delimiting the solstice) is engraved in the ground, so i think it is an permanent analemma, for multiple years...

Thanks !

Hi Philosophaie, hi everyone For setting, the formula is also : T = alpha - H or, if you prefer : LMST = alpha - HA ? That's it ? Can you tell me what do you mean with "just time changes" ? JD = julian day ? Why giving me the formula for Greenwich Mean sidereal time ?

Ok, sorry.

Sorry for the misunderstanding, but english is not my mother tongue. I agree analemma makes a figuer 8. On this figure 8, you have on the floor 365 marks for the 365 days of the year. You have also other indications like months, equinoxes, solstices, etc. But, on the figure 8, the position of...

Ok, thanks everybody !

Ok, but by doing this, you don't use spectroscopy at all (look first post of the thread...) ?

Anyone ?

Anyone ?

Anyone ?

Anyone ?

Ok. I looked at it. So ?

Hi, I knew T was LMST, but I don't understand why local mean sidereal time for the rising is given by LMST = alpha - H and by LMST = alpha + H for the setting (where alpha = right ascension). I have some ideas (see my precedent post) but I'm not sure... Thanks