Same galaxy, different filters

Esahubble_potw2346a_1024

esahubble_potw2346a November 13th, 2023

Credit: ESA/Hubble & NASA, R. Chandar, J. Lee and the PHANGS-HST team

This luminous tangle of stars and dust is the barred spiral galaxy NGC 1385, that lies about 30 million light-years from Earth. The same galaxy was the subject of another Hubble Picture of the Week, but the two images are notably different. This more recent image has far more pinkish-red and umber shades, whereas the former image was dominated by cool blues. This chromatic variation is not just a creative choice, but also a technical one, made in order to represent the different number and type of filters used to collect the data that were used to make the respective images. It is understandable to be a bit confused as to how the same galaxy, imaged twice by the same telescope, could be represented so differently in two different images. The reason is that — like all powerful telescopes used by professional astronomers for scientific research — Hubble is equipped with a range of filters. These highly specialised components have little similarity to filters used on social media: those software-powered filters are added after the image has been taken, and cause information to be lost from the image as certain colours are exaggerated or reduced for aesthetic effect. In contrast, telescope filters are pieces of physical hardware that only allow very specific wavelengths of light to enter the telescope as the data are being collected. This does cause light to be lost, but means that astronomers can probe extremely specific parts of the electromagnetic spectrum. This is very useful for a number of reasons; for example, physical processes within certain elements emit light at very specific wavelengths, and filters can be optimised to these wavelengths. Take a look at this week's image and the earlier image of NGC 1385. What are the differences? Can you see the extra detail (due to extra filters being used) in this week’s image? [Image Description: A spiral galaxy. It has several arms that are mixed together and an overall oval shape. The centre of the galaxy glows brightly. There are bright pink patches and filaments of dark red dust spread across the centre.] Links Pan of Same galaxy, different filters

Provider: Hubble Space Telescope | ESA

Image Source: https://esahubble.org/images/potw2346a/

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 1385
Esahubble_potw2346a_128
 

Position Details

Position (ICRS)
RA = 3h 37m 28.4s
DEC = -24° 30’ 3.1”
Orientation
North is 99.8° CCW
Field of View
2.7 x 2.6 arcminutes
Constellation
Fornax

Color Mapping

  Telescope Spectral Band Wavelength
Purple Hubble (WFC3) Ultraviolet (UV) 275.0 nm
Purple Hubble (WFC3) Optical (U) 336.0 nm
Blue Hubble (WFC3) Optical (B) 438.0 nm
Green Hubble (WFC3) Optical (V) 555.0 nm
Orange Hubble (WFC3) Optical (I) 814.0 nm
Red Hubble (WFC3) Optical (H-alpha + NII) 657.0 nm
Spectrum_base
Purple
Purple
Blue
Green
Orange
Red
Esahubble_potw2346a_1280
×
ID
potw2346a
Subject Category
Subject Name
NGC 1385
Credits
ESA/Hubble & NASA, R. Chandar, J. Lee and the PHANGS-HST team
Release Date
2023-11-13T06:00:00
Lightyears
Redshift
Reference Url
https://esahubble.org/images/potw2346a/
Type
Observation
Image Quality
Distance Notes
Facility
Hubble Space Telescope, Hubble Space Telescope, Hubble Space Telescope, Hubble Space Telescope, Hubble Space Telescope, Hubble Space Telescope
Instrument
WFC3, WFC3, WFC3, WFC3, WFC3, WFC3
Color Assignment
Purple, Purple, Blue, Green, Orange, Red
Band
Ultraviolet, Optical, Optical, Optical, Optical, Optical
Bandpass
UV, U, B, V, I, H-alpha + NII
Central Wavelength
275, 336, 438, 555, 814, 657
Start Time
Integration Time
Dataset ID
None, None, None, None, None, None
Notes
Coordinate Frame
ICRS
Equinox
J2000
Reference Value
54.368396611446684, -24.50085549930377
Reference Dimension
4069.0, 3925.0
Reference Pixel
2034.5, 1962.5
Scale
-1.1016993443820447e-05, 1.1016993443820447e-05
Rotation
99.800000000000125
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
potw2346a
Metadata Date
2023-11-03T19:33:10+01:00
Metadata Version
1.1
×

 

Detailed color mapping information coming soon...

×

There is no distance meta data in this image.

 

Providers | Sign In