Photography and exhibit design: Zolt Levay
Science consulting: Brandon Lawton
Writing: Margaret W. Carruthers
Graphics: Elizabeth Wheatley
Website design: Pam Jeffries
Additional contributions: Greg Bacon, Claire Blome, John Godfrey, Hussein Jirdeh, John Maple, Denise Smith, Sharon Toolan, Vonessa Schulze
Special thanks to the Art Association of Jackson Hole and Executive Director Mark Nowlin for hosting the exhibit.
a. Telescope Name: All of the images shown are photographs of light collected by NASA’s Hubble Space Telescope. In one case (Carina Nebula), the image is constructed using a combination of Hubble data and photographs from a ground-based observatory, the Cerro Tololo Inter-American Observatory in Chile.
b. Object Name: While some objects have common names related to their appearance or location, others are referred to only by their catalog numbers.
Arp: Galaxies with unusual shapes included in Halton Arp’s Atlas of Peculiar Galaxies, published in 1966
HCG: Group of four or more galaxies included in Paul Hickson’s catalog of Compact Groups of Galaxies, first published in 1982
M: Messier objects, cataloged by or based on observations made by Charles Messier in the late 18th century
NGC: Objects included in the New General Catalogue of Nebulae and Clusters of Stars, first published by John Emil Louis Dreyer in the late 19th century; the catalog has been updated a number of times
c. Constellations: Astronomers divide the sky into 88 adjoining regions, each named for a prominent constellation. The constellation given for each celestial landscape in this exhibit reflects its location in the sky, as seen from Earth.
d. Year: Year that the image was released to the public.
e. Credits: Credits reflect the organizations and teams involved in transforming Hubble data into the images shown here.
AURA: Association of Universities for Research in Astronomy
ESA: European Space Agency
Hubble Heritage: A project founded in 1998 dedicated to finding and publicizing visually compelling photographs from the Hubble Space Telescope. The Hubble Heritage team is composed of astronomers, image processing specialists, and telescope experts based at the Space Telescope Science Institute
NASA: National Aeronautics and Space Administration
STScI: Space Telescope Science Institute
SM4 ERO: Servicing Mission 4, Early Release Observation: observations made in 2009 to demonstrate upgrades made to Hubble during the last servicing mission
f. Exposure Date: The date that the image data were collected. Most images are constructed with data collected over a series of Hubble orbits. Some reflect data collected over a number of years (not continuously).
g. Instrument: In addition to the mirrors designed to collect and focus light from space, Hubble also includes of a set of scientific instruments designed to analyze light in different ways. The instruments used for the images shown here include:
ACS: The Advanced Camera for Surveys was designed to survey large areas of the sky. ACS was installed with several channels, including the Wide Field Channel (WFC), High Resolution Channel (HRC), and Solar-Blind Channel (SBC). ACS was installed during Hubble’s fourth servicing mission, in 2002.
WFPC2: The Wide Field Planetary Camera 2 was installed on Hubble during the first servicing mission, in 1993, and remained Hubble’s main camera until installation of the ACS in 2002.
WFC3: The Wide Field Camera 3 is designed to look at a range of objects, detecting not just visible, but also ultraviolet and near infrared light. WFC3 has two channels: ultraviolet-visible (UVIS) and near-infrared (IR). WFC3 replaced the WFPC2 in 2009.
Find out more about Hubble instruments.
h. Exposure time: Total number of hours that Hubble spent collecting light from the object. More time is required for fainter objects.
i. Filters: When Hubble images an object in the sky, it does not capture all of the wavelengths (colors) of light at once. Instead, various filters are used: Each filter blocks out colors that the astronomers are not interested in, allowing only certain wavelengths or ranges of wavelengths into the detectors. The choice of filters depends on the type of object being observed (e.g., star vs. nebula) and what the astronomers are trying to find out about the object (e.g., its composition, structure, temperature, or motion) .
Filters are named by the specific wavelength or dominant wavelength of light that they let through: 502 nm = 502 nanometers (1,000,000,000 nm = 1 meter). Some of these wavelengths correspond to the wavelengths of light emitted by specific elements, like hydrogen, oxygen, or sulfur. Letters in parentheses refer to standard filters recognized across astronomy.
j. Color Assignments: The final images are made by assigning each filter a color, and then combining the colors. In most cases, the colors that are assigned to a specific filter are representative of the actual color of visible light that is being measured. For example, to create the Saturn image, the 439 nm filter was assigned as blue; the 555 nm as green, and the 675 nm as red. The image looks like Saturn looks to our eyes because we actually see light with wavelength of 439 nm as blue; 555 nm as yellowish-green, and 675 nm as orange-red. In other cases, colors are chosen to better show the composition or structure of the object, and the colors don’t really show us the true color of the object. Finally, some of the images in this exhibit include ultraviolet or infrared, as well as visible light. Our eyes cannot detect UV or IR, but those filters are also assigned a visible color so that we can visualize the data. Because UV is just beyond the violet end of the visible-light spectrum (ultraviolet), it is often assigned a blue or purple color; IR is just beyond the red end, and is generally assigned a red color.
k. Description: Information about each image is based on careful scientific analysis of Hubble data by astronomers and astrophysicists across the world. Additional information about the research and the scientists involved in each project can be found on the Find out more links. Click here for definitions of terms used in the descriptions.
Definitions for more astronomy terms can be found here.
Visit Hubblesite.org for more information about the Hubble Space Telescope; the objects, processes, and materials shown in the images; the data used to construct each image; the scientific investigations that each image is tied to; and NASA’s future missions, the James Webb Space Telescope and WFIRST.
For more information on how Hubble images are constructed and the convergence of art and science in Hubble images and American landscapes, see Hubble’s Legacy: Reflections by those who dreamed it, built it, and observed the universe with it (Roger D. Launius and David H. DeVorkin, Eds., 2014)
- “Creating Hubble’s Imagery” by Zolt Levay (Chapter 9)
- “Displaying the Beauty of the Truth: Hubble Images as Art and Science” by Elizabeth Kessler (Chapter 10)