Dim, but still distinct

Esahubble_potw2405a_1024

esahubble_potw2405a January 29th, 2024

Credit: ESA/Hubble & NASA, R. J. Foley (UC Santa Cruz)

This image of the spiral galaxy UGC 11105 is not as bright and vivid as some other Hubble Pictures of the Week. This softly luminous galaxy — lying in the constellation Hercules, about 110 million light-years from Earth — seems outshone by the sparkling foreground stars that surround it. The type II supernova which took place in this galaxy in 2019, while no longer visible in this image, definitely outshone the galaxy at the time! To be more precise, UGC 11105 has an apparent magnitude of around 13.6 in the optical light regime (this image was created using data that covers the heart of the optical regime, in addition to ultraviolet data). Astronomers have different ways of quantifying how bright celestial objects are, and apparent magnitude is one of them. Firstly, the ‘apparent’ part of this quantity refers to the fact that apparent magnitude only describes how bright objects appear to be from Earth, which is not the same thing as measuring how bright they actually are. For example, in reality the variable star Betelgeuse is about 21 000 times brighter than our Sun, but because the Sun is much, much closer to Earth, Betelgeuse appears to be vastly less bright than it. The ‘magnitude’ part is a little harder to describe, because the magnitude scale does not have a unit associated with it, unlike, for example, mass, which we measure in kilograms, or length, which we measure in metres. Magnitude values only have meaning relative to other magnitude values. Furthermore, the scale is not linear, but is a type of mathematical scale known as ‘reverse logarithmic’, which also means that lower-magnitude objects are brighter than higher-magnitude objects.  As an example, UGC 11105 has an apparent magnitude of around 13.6 in the optical, whereas the Sun has an apparent magnitude of about -26.8. Accounting for the reverse logarithmic scale, this means that the Sun appears to be about 14 thousand trillion times brighter than UGC 11105 from our perspective here on Earth, even though UGC 11105 is an entire galaxy! The faintest stars that humans can see with the naked eye come in at about sixth magnitude, with most galaxies being much dimmer than this. Hubble, however, has been known to detect objects with apparent magnitudes up to the extraordinary value of 31, so UGC 11105 does not really present much of a challenge.  [Image Description: A spiral galaxy, with two prominent arms that are tightly wound around the brighter core. The arms disperse into a wide halo of stars and dust at their ends, giving the galaxy an oval shape. It is flanked by a number of bright stars in the foreground, each with a little cross over it due to light diffraction, and some distant background galaxies as well.] Links Pan: Dim, but still distinct

Provider: Hubble Space Telescope | ESA

Image Source: https://esahubble.org/images/potw2405a/

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

Image Use Policy: Creative Commons Attribution 4.0 International License

Image Details

Image Type
Observation
Object Name
UGC 11105
Esahubble_potw2405a_128
 

Position Details

Position (ICRS)
RA = 18h 4m 36.9s
DEC = 21° 38’ 30.4”
Orientation
North is 43.9° CCW
Field of View
2.2 x 1.3 arcminutes
Constellation
Hercules

Color Mapping

  Telescope Spectral Band Wavelength
Blue Hubble (WFC3) Optical (V) 555.0 nm
Green Hubble (WFC3) Optical (V) 555.0 nm
Green Hubble (WFC3) Optical (I) 814.0 nm
Red Hubble (WFC3) Optical (I) 814.0 nm
Spectrum_base
Blue
Green
Green
Red
Esahubble_potw2405a_1280
×
ID
potw2405a
Subject Category
Subject Name
UGC 11105
Credits
ESA/Hubble & NASA, R. J. Foley (UC Santa Cruz)
Release Date
2024-01-29T06:00:00
Lightyears
Redshift
Reference Url
https://esahubble.org/images/potw2405a/
Type
Observation
Image Quality
Distance Notes
Facility
Hubble Space Telescope, Hubble Space Telescope, Hubble Space Telescope, Hubble Space Telescope
Instrument
WFC3, WFC3, WFC3, WFC3
Color Assignment
Blue, Green, Green, Red
Band
Optical, Optical, Optical, Optical
Bandpass
V, V, I, I
Central Wavelength
555, 555, 814, 814
Start Time
Integration Time
Dataset ID
None, None, None, None
Notes
Coordinate Frame
ICRS
Equinox
J2000
Reference Value
271.15372109925454, 21.64178987406074
Reference Dimension
3344.0, 2043.0
Reference Pixel
1672.0, 1021.5
Scale
-1.1010663488878615e-05, 1.1010663488878615e-05
Rotation
43.88000000000001
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
potw2405a
Metadata Date
2024-01-23T17:22:26+01:00
Metadata Version
1.1
×

 

Detailed color mapping information coming soon...

×

There is no distance meta data in this image.

 

Providers | Sign In