With the Hubble Space Telescope, we have looked back in time and witnessed a rich diversity of galaxies growing, merging, and taking shape over 13 billion years of cosmic history. But the most distant galaxies in the early universe are too small and faint to study in detail with Hubble, leaving us with many questions. When did the first stars and galaxies form? Did any early galaxies look like our Milky Way? And what were they made of?

The James Webb Space Telescope (JWST) is beginning to answer these questions and pose new ones. In only its second year of operation, JWST has already taken a giant leap towards discovering the first stars. Dan Coe '07, a recipient of the 2023 JHU Distinguished Alumnus Award, and NASA postdoctoral fellow Taylor Hutchison will discuss how scientists at the Space Telescope Science Institute made observations using gravitational lensing that reveal individual stars including Earendel observed 13 billion years ago, observed star clusters dating back to even earlier times in the Cosmic Gems Arc, and used spectroscopy to reveal heavy elements created by stars less than 400 million years after the Big Bang.

The conversation is moderated by NASA Thermal Engineer Emily Maheras, WSE '23 (MA)

#hopkinsathome #johnshopkins #jhu #jameswebbspacetelescope #jwst #hubble #hopkins #stsci #gravitationallensing #redshifting #earendel #spectroscopy #nasa

Chapter Markers:
0:00 - Intro
0:22 - Welcome
1:43 - Introductions
3:00 - Our Cosmic Voyage Begins
4:14 - Hubble Ultra Deep Field Images
5:34 - Gravitational Lensing
6:55 - JWST Images
7:27 - Taylor shares info about JWST
10:25 - Chemical Composition of the Universe
11:26 - How JWST uses Spectroscopy to see distant galaxies
15:14 - Dan shares how we can all see lensing effect example at home
15:56 - Revisiting images from Hubble, now with JWST
17:01 - JWST Spectroscopy identifies elements in distant galaxies
18:22 - The Smudge and “Splitting the Atom”
20:46 - “Splitting the Atom” even further - Individual Stars
21:31 - Earendel - The Most Distant Observed Galaxy Cluster
23:30 - Spectroscopy is necessary to understand stars better / Godzilla
25:55 - JWST Goals / The first stars
27:02 - Can we find them?
28:08 - Forecasting near future of telescope technology
29:40 - Q+A Segment
30:03 - What potential future results are you most excited about w/JWST?
32:27 - Where do the names of the stars/galaxies come from? Does whoever find it get to name it?
33:48 - With multiple-lensed images of an object, are the images at different times? Is this a way to simultaneously observe the same object at different points in cosmological evolutionary time?
35:24 - What causes the red shift in light as it travels through space and time? Is it interactions with gas clouds or other matter in space?
37:30 - How do working scientists approach higher and higher redshifts? Are high values reliable or can they be prone to more error? And lastly, do they cause any concern or worry as you gather and analyze observations?
40:10 - Since size and mass are not necessarily correlated, how does the mass of the large early stars compare to the most massive stars that form today?
41:47 - Are there any new theories or surprising findings related to black holes?
43:33 - Can you give a brief explanation on how the photos that you share differ from what our eyes would see if we were actually there and why? How?
45:35 - Is red shifting a doppler effect?
46:46 - Could you share what has been the most rewarding part of working on JWST?