It’s all relative

Esahubble_potw2352a_1024

esahubble_potw2352a December 25th, 2023

Credit: ESA/Hubble & NASA, J. Dalcanton, Dark Energy Survey/DOE/FNAL/NOIRLab/NSF/AURAAcknowledgement: L. Shatz

This Hubble Picture of the Week features a richness of spiral galaxies: the large, prominent spiral galaxy on the right side of the image is NGC 1356; the two apparently smaller spiral galaxies flanking it are LEDA 467699 (above it) and LEDA 95415 (very close at its left) respectively; and finally, IC 1947 sits along the left side of the image.  ThIs image is a really interesting example of how challenging it can be to tell whether two galaxies are actually close together, or just seem to be from our perspective here on Earth. A quick glance at this image would likely lead you to think that NGC 1356, LEDA 467699 and LEDA 95415 were all close companions, whilst IC 1947 was more remote. However, we have to remember that two-dimensional images such as this one only give an indication of angular separation: that is, how objects are spread across the sphere of the night sky. What they cannot represent is the distance objects are from Earth.  For instance, whilst NGC 1356 and LEDA 95415 appear to be so close that they must surely be interacting, the former is about 550 million light-years from Earth and the latter is roughly 840 million light-years away, so there is nearly a whopping 300 million light-year separation between them. That also means that LEDA 95415 is likely nowhere near as much smaller than NGC 1356 as it appears to be. On the other hand, whilst NGC 1356 and IC 1947 seem to be separated by a relative gulf in this image, IC 1947 is only about 500 million light-years from Earth. The angular distance apparent between them in this image only works out to less than four hundred thousand light-years, so they are actually much much closer neighbours in three-dimensional space than NGC 1356 and LEDA 95415! [Image Description: A collection of galaxies. On the left side a large spiral galaxy with swirling, twisted arms is flanked by a smaller, but still detailed, spiral behind its arm on the left, and a smaller spiral above it. On the right side is a fourth, round spiral galaxy seen face-on. Between them lies a single bright star. Several stars and distant galaxies dot the background.] Links Pan: It’s all relative

Provider: Hubble Space Telescope | ESA

Image Source: https://esahubble.org/images/potw2352a/

Curator: ESA/Hubble, Baltimore, MD, United States

Image Use Policy: Creative Commons Attribution 4.0 International License

Image Details

Image Type
Observation
Object Name
NGC 1356
Esahubble_potw2352a_128
 

Position Details

Position (ICRS)
RA = 3h 30m 37.0s
DEC = -50° 19’ 7.1”
Orientation
North is 115.5° CW
Field of View
3.3 x 3.1 arcminutes
Constellation
Horologium

Color Mapping

  Telescope Spectral Band Wavelength
Blue Blanco-4m (DECam) Optical (g) 474.0 nm
Green Blanco-4m (DECam) Optical (r) 644.0 nm
Red Blanco-4m (DECam) Optical (z) 919.0 nm
Luminosity Hubble (ACS) Optical (V) 606.0 nm
Spectrum_base
Blue
Green
Red
Luminosity
Esahubble_potw2352a_1280
×
ID
potw2352a
Subject Category
Subject Name
NGC 1356
Credits
ESA/Hubble & NASA, J. Dalcanton, Dark Energy Survey/DOE/FNAL/NOIRLab/NSF/AURAAcknowledgement: L. Shatz
Release Date
2023-12-25T06:00:00
Lightyears
Redshift
Reference Url
https://esahubble.org/images/potw2352a/
Type
Observation
Image Quality
Distance Notes
Facility
Víctor M. Blanco 4-meter Telescope, Víctor M. Blanco 4-meter Telescope, Víctor M. Blanco 4-meter Telescope, Hubble Space Telescope
Instrument
DECam, DECam, DECam, ACS
Color Assignment
Blue, Green, Red, Luminosity
Band
Optical, Optical, Optical, Optical
Bandpass
g, r, z, V
Central Wavelength
474, 644, 919, 606
Start Time
Integration Time
Dataset ID
None, None, None, None
Notes
Coordinate Frame
ICRS
Equinox
J2000
Reference Value
52.654112007958446, -50.318649159173404
Reference Dimension
4012.0, 3709.0
Reference Pixel
2006.0, 1854.5
Scale
-1.3896301264403685e-05, 1.3896301264403685e-05
Rotation
-115.51999999999978
Coordinate System Projection:
TAN
Quality
Full
FITS Header
Notes
Creator (Curator)
ESA/Hubble
URL
https://esahubble.org
Name
Email
Telephone
Address
ESA Office, Space Telescope Science Institute, 3700 San Martin Dr
City
Baltimore
State/Province
MD
Postal Code
21218
Country
United States
Rights
Creative Commons Attribution 4.0 International License
Publisher
ESA/Hubble
Publisher ID
esahubble
Resource ID
potw2352a
Metadata Date
2023-12-22T18:10:40.734474
Metadata Version
1.1
×

 

Detailed color mapping information coming soon...

×

There is no distance meta data in this image.

 

Providers | Sign In