BHEX Mini

(Black Hole Explorer Mini)

Ref Bari

Physics MS, Brown

• Analysis of Binary Black Holes via Neural Networks (under Prof. Brendan Keith, Brown)

  • Funded under NSF Neural DynAMO Grant

• “Nitrogen Outgassing from Water Worlds” (R.Bari et. al., under review, The Astrophysical Journal 2025)

• “Reflection from Relativistic Light Sails” (R. Bari, The Astronomical Journal 2024)

• “Simulating the Action Principle in Optics” (R. Bari, The Physics Teacher 2023)

• Spin Qubit CNN Researcher at the Meriles Condensed Matter Lab

• “A Path Integral Derivation of Hawking Radiation” (MS Thesis)

Binary Black Holes

Physics MS, Brown

• Analysis of Binary Black Holes via Neural Networks (Prof. Brendan Keith, Brown)

  • Funded under NSF Neural DynAMO Grant

Binary Black Holes

Physics MS, Brown

Black Hole (M87)

Why is it so hard to image a black hole?

How far away is M87?

How big is M87?

Imaging a Black Hole

Black Holes: An Intro

Event Horizon Telescope (EHT)

Black Holes: An Intro

Black Hole Explorer Satellite (BHEX) Mission

Imaging a Black Hole

(The black hole explorer: Motivation and vision, Johnson et. al., 2024)

Imaging a Black Hole

Imaging a Black Hole

Imaging a Black Hole

Imaging a Black Hole

Imaging a Black Hole

Imaging a Black Hole

Imaging a Black Hole

Imaging a Black Hole

Imaging a Black Hole

99%

Chance of failure

Reasons to Hope

• Current proposal demonstrates ...
  • A second satellite does increase the interferometric resolution

Reasons to Hope

• Current proposal demonstrates ...
  • A second satellite does increase the interferometric resolution
  • The minimum weight for a second satellite is ~ 200 kg 

Reasons to Hope

• Current proposal demonstrates ...
  • A second satellite does increase the interferometric resolution
  • The minimum weight for a second satellite is ~ 200 kg
• BHEX Team will meet in June

Reasons to Hope

• Current proposal demonstrates ...
  • A second satellite does increase the interferometric resolution
  • The minimum weight for a second satellite is ~ 200 kg
• BHEX Team will meet in June
• Publish final BHEX Mini proposal on arXiv

Reasons to Hope

• Current proposal demonstrates ...
  • A second satellite does increase the interferometric resolution
  • The minimum weight for a second satellite is ~ 200 kg
• BHEX Team will meet in June
• Publish final BHEX Mini proposal on arXiv
• Corresponding with Ben Hudson, PhD Candidate at TU Delft (BHEX Team)

BHEX Mini

Physics

Engineering

Imaging

BHEX Mini

Physics

Imaging

Engineering

BHEX Mini

Physics

Imaging

Engineering

BHEX Mini

Physics

Imaging

Engineering

Physics

Questions: 

1. What is the interferometric signature of the photon ring?
2. What are the orbital constraints on BHEX + BHEX Mini if it seeks to detect n = 1 photon ring?
3. What is the geometry of a rotating black hole?
4. What is the photon ring?
5. Why is the photon ring "quantized" into subrings?
6. What is the black hole shadow, and how is it different from the photon ring?
7. What is the photon ring shape predicted by the Kerr Metric? 
8. How exactly can constrain a black hole's spin by detecting the photon ring?
9. Can BHEX detect hawking radiation?
10. What is the critical curve for a photon ring?

Physics

Physics

BHEX Mini

Physics

Imaging

Engineering

Engineering

Questions: 

1. What is the simplest possible way to do radio interferometery using a CubeSat?
2. What are the mass + power requirements breakdown for BHEX & BHEX Mini?
3. Total cost for BHEX Mini?
4. How does interforemetric resolution scale with the diameter of the radio antenna?
5. How would BHEX Mini connect with ground stations? How would it connect with the main BHEX satellite?
6. What type of radio antenna would BHEX Mini have? (i.e., Phased Array, Standard, etc.)
7. What is the temperature requirement for the antenna?
8. How do you put a radio antenna on a CubeSat?
9. What type of cyrocooler will maintain the antenna at the required temperature?

Engineering

Engineering

BHEX Mini

Physics

Imaging

Imaging

Questions: 

1. How does Very-Long Baseline Interferometry (VLBI) work?
   1. aka How do multiple radio telescopes combine into a single large telescope?
2. Why does going into space decrease the angular resolution?
3. What configuration of BHEX + BHEX Mini would minimize the angular resolution?

Imaging

BHEX Mini Timeline

Thursdays (6 PM) + Sundays (1:30 PM)

2 Weeks: 4/15-4/30 | Literature Review

BHEX Mini Timeline

Thursdays (6 PM) + Sundays (1:30 PM)

2 weeks: 5/1-5/15 | Simulations

BHEX Mini Timeline