Right Ascension not displayed correctly using decimal degrees

[Stephen Aman]

When switching to decimal degrees, Stellarium works fine for Hour Angle, but not for Right Ascension. It shows the Hour Angle in the decimal fraction of an hour - which is exactly what you want. It should do the same for Right Ascension, but does not. Right Ascension is usually not written as a longitude.

[Alexander Wolf (alexwolf)]

It works correct. Hour Angle is always in hours. RA may show in decimal (always degrees) or sexagesimal (always hours) format. It's standard scientific notation for RA/HA.

[Stephen Aman (amanharnden)]

Okay, thank you for your immediate response.

Is there a setting in Stellarium that would change the "RA/Dec" display field to read in decimal hours as it does for the "HA/Dec" display field?

Example:

Change the default:
 RA/Dec (J2000.0): 20h36m00.00s/25°12'00.0"

To read:
 RA/Dec (J2000.0): 20.60000h/25.2000°

And not the way that the "use decimal degrees" option reads:
 RA/Dec (J2000.0): +309.00000°/25.2000°

Many robotic telescopes need to have the RA/Dec entered in this fashion (Ex: RA= 20.60000h Dec= 25.2000°).

If this option is not available, maybe it could be added to future versions of Stellarium.

Thank you for your time.

[Alexander Wolf (alexwolf)]

> Many robotic telescopes need to have the RA/Dec entered in this fashion
(Ex: RA= 20.60000h Dec= 25.2000°).

Please give examples of these robotic telescopes, because it big surprise for me.

[Alexander Wolf (alexwolf)]

Any news?

[Stephen Aman (amanharnden)]

Slooh, one of the biggest outlets for worldwide online robotic telescope use, has just recently promoted Stellarium to hundreds of its members. They are now using Stellarium to book telescope missions. The problem is that once they obtain the RA/Dec information, the RA has to be converted to decimal hours before they can schedule a mission.

It's not that big of an issue really. If the RA can't be displayed that way, then so be it. Dividing the displayed RA by 15 gives the result needed. It just would be nice not to have to go to that trouble.

I thank you for your time with this matter. Maybe I'll be surprised and see a new option in future versions of Stellarium that will allow a display change. Again thanks, Stephen Aman

[gzotti (georg-zotti)]

Maybe Slooh can extend their interface if they promote Stellarium? Decimal hours are really uncommon, in all its conversion triviality.

[Alexander Wolf (alexwolf)]

Slooh is really use the decimal hours for RA O_O

[gzotti (georg-zotti)]

But we should regard it as Slooh issue, they could also fix their input form easily.

Other projects also have their problems, see e.g. https://github.com/astropy/astropy/issues/1115. Nowhere they discuss decimal hours.