Omega Centauri in narrowband: Ha and Oiii (Freestar8n)

Celestial hemisphere: Southern · Constellation: Centaurus (Cen) · Contains: NGC 5139 · Omega Centauri · omega Cen

Omega Centauri in narrowband: Ha and Oiii

This was an experiment to see how well star populations can show when imaging a globular with two narrowband filters: Ha and Oiii. The result is a happy surprise - the bright orangish stars are main sequence - and sprinkled in the background are blue stars all of about the same brightness - and they are horizontal branch. Meanwhile there are a few faint red stars and some bright blue ones also. I believe they are unrelated foreground (red) and background (blue) stars.

The seeing was good on these two nights, with fwhm's down to 1.2" in 5m exposures. The good seeing combined with a full moon motivated me to try this.

The image has had no smoothing, sharpening or cropping. The only processing involved was to map the two color channels to RGB in Maxim, then stretch the colors in PS. Only global operations were performed.

EdgeHD11 at f/10 with ASI1600MMPro. 40x5m exposures in each filter. Video-guided with MetaGuide and corrections every second with CGX-L mount. Calibrated and stacked in custom software.

Autofocused with custom software using a stepper on the primary mirror focus knob, with refocus every 40 minutes. Dithered every exposure. Two imaging sessions on successive nights with 100% yield and all exposures stacked.

Original
Final
B

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	Advanced success
Started	...
Astrometry.net job	4717611
PixInsight job	H7BE1L2ZDKYFMP4VAEZ2M4W6JU125TKC
PixInsight queue size	n/a
PixInsight stage	TASK_LOG

RA (center)	13h26m52s.170
RA (top/left)	13h25m31s.524
RA (top/right)	13h27m08s.518
RA (bottom/right)	13h28m12s.867
RA (bottom/left)	13h26m35s.954

Dec (center)	-47°29′35″.49
Dec (top/left)	-47°28′33″.98
Dec (top/right)	-47°42′58″.65
Dec (bottom/right)	-47°30′34″.16
Dec (bottom/left)	-47°16′12″.51

Image Index:

Contribution Index (beta):

Omega Centauri in narrowband: Ha and Oiii

Omega Centauri in narrowband: Ha and Oiii

Equipment

Acquisition details

Description

Comments

Revisions

Sky plot

Histogram

		...
You have no new notifications.

Image Index:

Contribution Index (beta):

Omega Centauri in narrowband: Ha and Oiii

Omega Centauri in narrowband: Ha and Oiii

Equipment

Acquisition details

Description

Comments

Revisions

Sky plot

Histogram

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?

Delete this revision?

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