I How Do You Convert Parsecs to Arcminutes in Astrophysics?

[mmont012]

Can someone help me convert 1.2 parsecs into arcminutes?

I'm currently doing an internship that does astrophysics research and the grad student told me to do this conversion. I need it to get the data that I need to make tables, but I'm just confused.

I asked for help but they said that this information was all that I needed to make the conversion.

Any help is greatly appreciated.

 

[Drakkith]

I'm not sure you can directly convert those quantities. A parsec is a unit of distance but an arcminute is an angle. Is there any other information you can give us? What information is going to be in these tables?

 

[mmont012]

The tables show the location of individual stars that are in a cluster around a more massive central star. And she wants the data for all tge stars that are 1.2 parsecs away from the center one but the website requires that I put it in arcminutes (90 max). I told her that I thought that I was missing some information but she said that I had everything that I needed.

I showed her an equation that I came across which is theta=size (in AU) / distance (in parsecs)
Then I can convert radians to arcminutes.

She said yes that I just convert 1.2 parsecs into AU and then said that it was an easy conversion...

I'm lost. I'm sorry that I don't have more.

 

[phyzguy]

You need to know the distance to the cluster. Then the angular distance of a star from the center of the cluster is just:

angular distance of a star from the center of the cluster = distance of the star from the center of the cluster (in parsecs) / distance to the cluster (in parsecs)

 

[AgentCachat]

1 parsec =1/arsec (arcsec=1/60 arcmin)
multiply by 1.2 to get 1.2/arcsec, then convert to arcmin.
This gives you apparent angular size at 1.2 parsecs.
AU and Parsec relationship : 1 AU = 149,597, 000 kilometers = 1.49597E10 meters
1 pc= 3.0857E16 meters =2.0662E5 AU
1AU = just under 5E-6 pc

 

[davenn]

1 parsec =1/arsec (arcsec=1/60 arcmin)

have you a reference for this, it doesn't sound correct ?
I cannot see how you can have a distance equalling an angular measurement without having more info
namely the distance between you and the objects

the angular measurement of separation of 2 objects a parsec apart is going to be very different for me, the observer if I am at 10 lightyears distance compared to if I am 100 lightyears distance from themDave

 

[phyzguy]

have you a reference for this, it doesn't sound correct ?
I cannot see how you can have a distance equalling an angular measurement without having more info
namely the distance between you and the objects

the angular measurement of separation of 2 objects a parsec apart is going to be very different for me, the observer if I am at 10 lightyears distance compared to if I am 100 lightyears distance from them
Dave

Yes. As davenn says, and as I said in Post #4, you need to know the distance to the cluster in order to do the calculation.

@mmont012 - have you resolved the issue?

 

[mmont012]

She gave me a new piece of information; the distance of the cluster is 1.7 kpc. Thank you all for your help! It is truly appreciated!