NGC 1721, NGC 1723, NGC 1725, and NGC 1728 (rhedden)

Celestial hemisphere: Southern · Constellation: Eridanus (Eri) · Contains: NGC 1723

NGC 1721, NGC 1723, NGC 1725, and NGC 1728, rhedden

Powered byPixInsight

NGC 1721, NGC 1723, NGC 1725, and NGC 1728

Powered byPixInsight

NGC 1721, NGC 1723, NGC 1725, and NGC 1728

The NGC 1723 Group (aka NGC 1721 group, VV 699) lies in Eridanus not too far southwest of the bright star Rigel at about -11 degrees declination. The lone barred spiral at the left of the field is NGC 1723 (left) at a magnitude of about 12.5. Other members at the center of the field are NGC 1721 (top, mag. 13.8), NGC 1725 (middle, mag. 12.8) and NGC 1728 (bottom, mag. 13.9), while the 15th magnitude galaxy off to the right is PGC 16507. Magnitudes are from the SkyX. The three galaxies at the center lie at similar distances of about 170-200 million light years and are possibly interacting, though not much has been published on the subject, evidently. Lacking a catchy name, and dodging inclusion in several well-known catalogues, this impressive group is seldom imaged.

Seeing was average to very good on both nights, but this object is at low enough altitude to cause some problems with my setup with gradients and color balance in RGB frames due to refraction effects. Processing was somewhat problematic. I'm not sure I got the colors right, even after color calibrating with nearby stars, some of which were lime green even after the calibration. So please take any color information as non-scientific, given the liberal processing adjustments made.

AstroBin Platform open discussions community forum
Cloudy Nights
N.I.N.A. Users

Please note: The following tables are updated every 24 hours.

Distribution of astrophotographers

This table shows the number of distinct astrophotographers who have been assigned and IOTD/TP award compared to the total number of images awarded.
	Distinct awarded users	Total awarded images
Image of the day
Top picks
Top pick nominations

Distribution of subject types

This table shows the distribution of awards per subject type, compared to the popularity of images of that subject type.
	Image of the day	Top pick	Top pick nominations	Total submitted
Deep sky
Solar system
Extremely wide field
Star trails
Northern lights
Noctilucent clouds
Landscape

Distribution of data sources

This table shows the distribution of awards per data source, compared to the popularity of images acquired from that data source.
	Image of the day	Top pick	Top pick nominations	Total submitted
Backyard
Traveller
Own remote observatory
Amateur hosting facility
Public amaeteur data
Professional, scientific grade data
Mix of multiple sources
Other
Unknown

The “AstroBin Image of the Day and Top Picks”, or IOTD/TP, is a long-running system to promote beautiful, interesting, peculiar, or otherwise amazing astrophotographs, with a focus on technical excellence. Learn more.

Submitted The date and time when you submitted this image for IOTD/TP consideration.	...
Views by Submitters (available since September 19th, 2023) Every image is assigned to 50% of available Submitters. In the event that at least 80% of them don't view the image before its time in the IOTD/TP process expires, it's assigned to the other 50% of Submitters and the process begins anew.
Promotions by Submitters When 3 distinct Submitters promote the image, it moves on to the next stage of the process: evaluation for Top Pick status. This requirement, in addition to anonymization of images and distribution to only a subset of them, prevents biases and ensures that the best images are selected.
Promotions by Reviewers When 3 distinct Reviewers promote the image, it moves on to the next stage of the process: evaluation for IOTD status.
Early dismissal Staff members have a lot of images to inspect on a daily basis, and they can dismiss images if they believe they don't meet the requirements for IOTD/TP selection. If an image is dismissed 5 times, it's removed from the process. This streamlines the process and ensures that any bias present in promotions could be overruled by other staff members.

Status	Basic success
Started	...
Astrometry.net job	511500
PixInsight job	n/a
PixInsight queue size	n/a
PixInsight stage	n/a

Image Index:

Contribution Index (beta):

NGC 1721, NGC 1723, NGC 1725, and NGC 1728

NGC 1721, NGC 1723, NGC 1725, and NGC 1728

Equipment

Acquisition details

Description

Comments

Sky plot

Histogram

In these public groups

		...
You have no new notifications.

Image Index:

Contribution Index (beta):

NGC 1721, NGC 1723, NGC 1725, and NGC 1728

NGC 1721, NGC 1723, NGC 1725, and NGC 1728

Equipment

Acquisition details

Description

Comments

Sky plot

Histogram

In these public groups

Notifications

AstroBin is in READ ONLY mode

Sorry :-(

Sorry :-(

Sorry :-(

Are you really sure?

Warning!

Warning!

Are you sure?

Report abuse

Slideshow settings

IOTD/TP stats (last [x] days)

Distribution of astrophotographers

Distribution of subject types

Distribution of data sources

Sorry

Sorry

Share

Upload new revision

Upload uncompressed source (XISF/FITS/PSD/TIFF)

Delete image and all its revisions?

Delete original image?

Delete all other versions?

Delete all revisions?

IOTD/TP stats

The following people like this image

The following people bookmarked this image

Warning

Flag malfunctioning thumbnails

Contains

Remove yourself as a collaborator

Plate-solving information