NASA/IPAC/R. Hurt TripleSpec: A Union of Engineering and Infrared Astronomy

Angie Wolfgang

James Lloyd Astronomy Department Cornell University

What is TripleSpec?

A spectrometer . . . NASA/IPAC/R. Hurt Visible: 0.4μm to 0.7μm TripleSpec: 0.8μm to 2.5μm that separates wavelengths of near-infrared light . . .

which was emitted by faint sources: • small, cool stars • brown dwarfs NASA/ESA/G. Bacon

What do we hope to find?

NASA/IPAC/R. Hurt Exoplanets!

• To date, only ~250 detected • Most are gas giants like Jupiter • Smaller star, fainter signal . . . more Earth-like planet? How? Doppler Shift → Radial Velocity → Mass and Orbit of Planet Center of Mass b λ shift = λ o (1+v rad /c) v rad = b*(m planet /m star ) Period

Now to the engineering Top View: How do we separate the wavelengths?

NASA/IPAC/R. Hurt Optics!

• mirrors • prisms • diffraction grating • lenses Side View:

More engineering The detector: • measures intensity of light at different wavelengths • wavelengths mapped out in pattern across array 2048 pix NASA/IPAC/R. Hurt 1024 pix Prism dispersion Cross-dispersed!

Grating dispersion

To put it all together NASA/IPAC/R. Hurt Mechanical design: • infrared wavelengths → a lot of noise from heat h → optics must be cold!

• protect the optics!

• structural support • still worried about heat . . .

Bulkheads Liquid Nitrogen: 77K

Reduce thermal radiation NASA/IPAC/R. Hurt Need insulated layers!

Vacuum!

Outer case Inner tank G10: a poor thermal conductor 2

Still reducing radiation NASA/IPAC/R. Hurt More insulated layers . . .

Mylar Black Paint: • absorbs unwanted reflected light • slowly radiates extra heat into LN 2 , keeping inside cool

What I’ve done . . .

NASA/IPAC/R. Hurt

Three-bulkhead unit What I’ve done . . .

Assembly!

NASA/IPAC/R. Hurt Auxiliary tank Prism Box

What I’ve done . . .

Adhesion of glue at 77 K Testing!

NASA/IPAC/R. Hurt Laser alignment check Cryogenic performance of thermal fuses

What I’ve done . . .

Wiring!

Routing wires Learning how to solder Soldering two heater banks NASA/IPAC/R. Hurt

Working with hardware NASA/IPAC/R. Hurt It has been a different . . .

. . . but very rewarding experience!

Thank You!

NASA New York Space Grant Consortium Erica Miles Jamie Lloyd Terry Herter Chuck Henderson Steve Parshley Phil Muirhead Gustavo Rahmer Marco Bonati Joe Adams Babs Rojas NASA/IPAC/R. Hurt