# Which spacecraft far from Earth have arc second resolution cameras that could measure Betelgeuse's position?

All hands on deck! We have to measure the distance to Betelgeuse ASAP because Recent headlines saying that Betelgeuse is much closer than we thought, and they point to Standing on the Shoulders of Giants: New Mass and Distance Estimates for Betelgeuse through Combined Evolutionary, Asteroseismic, and Hydrodynamic Simulations with MESA which proposes in the abstract

...a new, independent distance estimate of $${168}_{-15}^{+27}$$ pc and a parallax of $$\pi ={5.95}_{-0.85}^{+0.58}$$ mas, in good agreement with Hipparcos but less so with recent radio measurements.

which is based on extensive modeling and then comparing to photometric data.

### Compare that 168 parsecs to Wikipedia's 220 parsecs!

Source Betelgeuse on 2020-10-18 click for larger

My question in Astronomy SE Can New Horizons be used to measure the distance to Betelgeuse (despite its fickle photocenter)? might end up with a positive or negative answer. New Horizons is out at about 50 AU, but it's hard to say what can be done with LORRI. Deep sub-pixel astrometric position measurements are "standard" meaning doable with the proper equipment and careful processing.

The point there is that because Betelgeuse is a weird lumpy brightness blob that's constantly changing, and normal parallax measurements have to wait for the Earth to move back and forth around the Sun a few times to separate out parallax, proper motion, and any instrumental effects, one could take advantage of simultaneous measurements using a deep space spacecraft and and a cis-lunar (e.g. Hubble) or Earthbound telescope to snap two photos at nearly the same time but with a wide separation.

Question: So I'd like to ask besides New Horizons (asked there already) which deep space spacecraft have high resolution (circa arc second) cameras that could image Betelgeuse against a nearby background of stars many times in order to try to get astrometric positions of this bright star?

• The LORRI camera of New Horizons has a resolution of 4.95 µrad or 1.02 arcseconds – Uwe Oct 19 '20 at 0:45
• @Uwe I think you'll enjoy reading this answer to Can New Horizons be used to measure the distance to Betelgeuse (despite its fickle photocenter)? – uhoh Oct 19 '20 at 0:48
• I did enjoy reading that answer. I did not think of "Betelgeuse is more than 10 times too bright" for LORRI. But this may be true for other deep space spacecrafts cameras too. All cameras designed for very dark objects. – Uwe Oct 19 '20 at 9:30
• "cameras that could image Betelgeuse against a nearby background of stars" but what if Betelgeuse is so much brighter than those background stars that there is no common exposure time useful for the bright and dark stars? – Uwe Oct 19 '20 at 9:35
• @Uwe Good point! Let's take it one step at a time. First identify a potential spacecraft camera, then see how it's designed, then see if it can be operated in a way that makes this even a little possible. If there's no potential spacecraft camera, then no need to worry about all the other stuff. There is discussion in Astronomy SE about pushing GAIA to measure brighter stars than it was designed, but I don't know if that helps here. See update: in this answer – uhoh Oct 19 '20 at 9:58