The galaxies in Hubble’s Frontier Fields project are so far away that they cannot be seen with either your eyes or a backyard telescope. It takes a state-of-the-art telescope like Hubble, Spitzer, or Chandra to collect enough of the scant photons streaming in from the most distant galaxies to produce a scientifically valuable image. In fact, Hubble’s views of the Frontier Fields, coupled with the natural lensing power of the galaxy clusters, allow astronomers to potentially detect objects that are 40 billion – yes, billion – times fainter than your eyes can see.

The galaxies in the Frontier Fields are so far away that they appear absolutely tiny in the night sky, even to Hubble. Hubble has the exquisite ability to resolve tremendously small features on the sky and discern details that would otherwise be blurred beyond recognition. If prior deep field observations are any indication, Hubble will observe thousands of galaxies in an area approximately the size of a pin-prick in a piece of paper held up at arm’s length.

The 12 Frontier Fields are located at six positions in the sky. You may not be able to see the Frontier Fields galaxies, but you can still find the area of the sky where they are located using the graphic below.  

The location of the Frontier Fields on the sky, using Right Ascension and Declination coordinates. The Frontier Fields are numbered in the order that Hubble plans to observe them over the three-year program. The names refer to the galaxy clusters targeted in each pointing. Each pointing also has an adjacent parallel field. A few of the previous Hubble deep-field observations are labeled as well – Hubble Deep Field North (HDF-N), Hubble Deep Field South (HDF-S), and the Hubble Ultra Deep Field (HUDF). The Milky Way in this coordinate system is shown as a wavy band of diffuse light across the sky.
SOURCES: Frontier Fields locations: STScI; All-sky star chart: J. Cornmell and
IAU

The map above uses a coordinate system familiar to astronomers. Right Ascension is similar to longitude in that it measures the position of an object east or west of a reference position. Right Ascension is measured in hours, from 0 to 24 hours, with the reference position set at 0 hours. Declination is similar to latitude. It measures the position of an object, in degrees from 0 to 90, north or south of a reference position. The reference position (0 degrees) for declination is the celestial equator, which is the projection of Earth’s equator onto the sky.  In this particular map we have truncated declination at 70 degrees north and south.

The Frontier Field’s site map (above) is a representation of the sky on a rectangular grid. When we view the sky from the surface of the Earth, it appears as the interior surface of a hemisphere, or dome — half of what people in ancient times referred to as the “celestial sphere” surrounding the Earth. Just as there are distortions when map-makers make a rectangular map of the spherical Earth, there are distortions in projecting the celestial sphere onto a rectangular grid. Constellations located near the northern and southern celestial poles (90 degrees north and south in declination) are represented on the map as spanning more of the sky than they actually do.

To help find the locations of the Frontier Fields, zoomed-in regions of the six pointings are shown below:

1) Abell 2744

Location of the Abell 2744 galaxy cluster field and its parallel field in the Sculptor constellation.
SOURCES: Frontier Field location: STScI; Enlarged constellation map: International Astronomical Union (IAU)

2) MACS J0416

Location of the MACS J0416 galaxy cluster field and its parallel field in the Eridanus constellation.
SOURCES: Frontier Field location: STScI; Enlarged constellation map: International Astronomical Union (IAU)

3) MACS J0717

Location of the MACS J0717 galaxy cluster field and its parallel field in the Auriga constellation.
SOURCES: Frontier Field location: STScI; Enlarged constellation map: International Astronomical Union (IAU)

4) MACS J1149

Location of the MACS J1149 galaxy cluster field and its parallel field in the Leo constellation.
SOURCES: Frontier Field location: STScI; Enlarged constellation map: International Astronomical Union (IAU)

5) Abell S1063

Location of the Abell S1063 galaxy cluster field and its parallel field in the Grus constellation.
SOURCES: Frontier Field location: STScI; Enlarged constellation map: International Astronomical Union (IAU)

6) Abell 370

Location of the Abell 370 galaxy cluster field and its parallel field in the Cetus constellation.
SOURCES: Frontier Field location: STScI; Enlarged constellation map: International Astronomical Union (IAU)

For more tips and information about observing the night sky, including access to free monthly sky charts, visit the NASA Night Sky Network. For monthly highlights of interesting objects to observe in the night sky, visit Hubblesite’s Tonight’s Sky.