# Figure out the location of celestial objects relative to the Milky Way in x, y, z co-ordinates

Astronomy Asked on December 21, 2020

I am trying to place various celestial objects the correct distance from the Milky Way, using x, y, z co-ordinates.
So assuming the centre-of-mass of the Milky Way is at 0, 0, 0 – how can I figure out where to place a galaxy or star given it’s celestial coordinates?

I’m just an amateur, and pushing 60 years old, so please excuse me if I have something wrong here…

The spherical $$(r, l, b)$$ can be converted to rectangular $$(U, V, W)$$ as:

begin{align} U &= r cos b cos l \ V &= r cos b sin l \ W &= r sin b end{align}

Using $$(r, l, b) = (770 pm 40 ~text{kpc}, 121.2^circ, -21.6^circ)$$,

begin{align} U &= -371 mp 19 ~text{kpc} \ V &= ~~~ 612 pm 32 ~text{kpc} \ W &= -283 mp 15 ~text{kpc} end{align}

That's relative to the Sun. For a position relative to the center of our galaxy, subtract $$8 pm 0.5 ~text{kpc}$$ from $$U$$.

Answered by Mike G on December 21, 2020

## Related Questions

### Has any of the orbiters or rover on Mars captured image of comet NEOWISE?

1  Asked on February 10, 2021

### What effects besides “mass defect” cause the alpha ladder beyond iron-56/nickel-56 to be endothermic?

1  Asked on February 10, 2021 by heatherb

### What’s the equation for moon-moon tidal heating?

1  Asked on February 9, 2021 by se-stop-firing-the-good-guys

### Size and Mass of a typical “small” asteroid that impacts the Earth?

2  Asked on February 8, 2021

### What are the pros and cons of angular cross-correlation in real space and harmonic space?

0  Asked on February 6, 2021 by astrolumos

### Number of actuators in adaptive optics

1  Asked on February 4, 2021 by truffaldino

0  Asked on February 4, 2021

### Is this a coincidence?

3  Asked on February 3, 2021 by tarit-goswami

### Is “Zero Shadow Day” necessary to perform Eratosthenes’ experiment?

2  Asked on January 16, 2021 by chetan-waghela

### Which star has the lowest absolute magnitude?

0  Asked on January 12, 2021 by fasterthanlight

### The drift of the Moon’s equatorial rotation velocity

1  Asked on January 3, 2021 by john-greene

### What determines if a comet’s debris will produce periodic meteor showers?

1  Asked on December 31, 2020 by mihirb

### Samples from the double Schechter luminosity funcion

0  Asked on December 30, 2020 by jm22b

### death of a red dwarf star / minimum mass needed for a white dwarf?

1  Asked on December 30, 2020 by userltk

### Why do we only have one major meteor shower from 3200 Phaethon?

1  Asked on December 28, 2020

### Corresponding values for the Sun’s ultra violet color maps?

2  Asked on December 25, 2020 by user2309000

### Figure out the location of celestial objects relative to the Milky Way in x, y, z co-ordinates

1  Asked on December 21, 2020

### How to send information from the far side of the Moon to the Earth?

1  Asked on December 20, 2020 by nightcod3r

### Life cycle of a gas planet?

1  Asked on December 15, 2020 by b-rian