by johnnydeep » Mon Jan 16, 2023 2:07 pm
alter-ego wrote: ↑Sun Jan 15, 2023 11:04 pm
johnnydeep wrote: ↑Sun Jan 15, 2023 10:36 pm
alter-ego wrote: ↑Sun Jan 15, 2023 10:29 pm
Yes. The star Ann appears to be pointing (Arrowed below) to is ~12 arcseconds south of the pulsar. The source below is Aladin. The crab pulsar labeled, and the boxes are stars from Gaia data. Some Gaia data for the pulsar (green highlighted box) is shown at the bottom of the image.
Pulsar ID Correct.JPG
Hmm, do the coordinates shown in the Gaia image match those here? -
https://www.universeguide.com/star/122592/crabpulsar
The location of the pulsar in the night sky is determined by the Right Ascension (R.A.) and Declination (Dec.), these are equivalent to the Longitude and Latitude on Earth. The Right Ascension (Longitude) is expressed in time (hh:mm:ss) and is how far along the celestial equator the star is. If the R.A. is positive, then its eastwards and vice versa.
The Declination (Latitude) is how far north or south the object is compared to the celestial equator and is expressed in degrees. If the value is positive then it is north of the celestial equator. For Crab Pulsar, the location is 05h 34m 31.97s and +22° 00` 52.1 .
Versus the coordinates from Gaia:
crab pulsar cooirdinates from gaia.png
The declination seems to match, but does the right ascension?
yes, within 7.5E-5 degrees (0.27 arcseconds). Close enough for government work
Ah. I was confused by the different units: degrees of RA versus hh:mm:ss of RA, where there are 24 hours in 360 degrees (1 hour is 15 degrees), 60 minutes in 1 hour, and 60 seconds in 1 minute. This calculator will do the conversion -
https://www.vercalendario.info/en/how/c ... hours.html
So, 83.63305 degrees is 5.57553666 hours, 0.5755366 hours is 34.5322 minutes, and 0.5322 minutes is 31.932 seconds , and so, 83.63305° is the same as 5h 34m 31.9s."
[quote=alter-ego post_id=328509 time=1673823875 user_id=125299]
[quote=johnnydeep post_id=328508 time=1673822207 user_id=132061]
[quote=alter-ego post_id=328507 time=1673821742 user_id=125299]
Yes. The star Ann appears to be pointing (Arrowed below) to is ~12 arcseconds south of the pulsar. The source below is Aladin. The crab pulsar labeled, and the boxes are stars from Gaia data. Some Gaia data for the pulsar (green highlighted box) is shown at the bottom of the image.
Pulsar ID Correct.JPG
[/quote]
Hmm, do the coordinates shown in the Gaia image match those here? - https://www.universeguide.com/star/122592/crabpulsar
[quote]The location of the pulsar in the night sky is determined by the Right Ascension (R.A.) and Declination (Dec.), these are equivalent to the Longitude and Latitude on Earth. The Right Ascension (Longitude) is expressed in time (hh:mm:ss) and is how far along the celestial equator the star is. If the R.A. is positive, then its eastwards and vice versa.
The Declination (Latitude) is how far north or south the object is compared to the celestial equator and is expressed in degrees. If the value is positive then it is north of the celestial equator. For Crab Pulsar, the location is [b][i]05h 34m 31.97s and +22° 00` 52.1[/i][/b] .[/quote]
Versus the coordinates from Gaia:
crab pulsar cooirdinates from gaia.png
The declination seems to match, but does the right ascension?
[/quote]
yes, within 7.5E-5 degrees (0.27 arcseconds). Close enough for government work :D
[/quote]
Ah. I was confused by the different units: degrees of RA versus hh:mm:ss of RA, where there are 24 hours in 360 degrees (1 hour is 15 degrees), 60 minutes in 1 hour, and 60 seconds in 1 minute. This calculator will do the conversion - https://www.vercalendario.info/en/how/convert-ra-degrees-hours.html
So, 83.63305 degrees is 5.57553666 hours, 0.5755366 hours is 34.5322 minutes, and 0.5322 minutes is 31.932 seconds , and so, 83.63305° is the same as 5h 34m 31.9s."