The Image Index is a system based on likes received on images, that incentivizes the most active and liked members of the community. Learn more.
The Contribution Index (beta) is system to reward informative, constructive, and valuable commentary on AstroBin. Learn more.
The planetary Medusa nebula Abell 21, or Sh2-274, has an apparent diameter of 10 arcminutes with a low average surface brightness magnitude of 19.92.
It is a planetary nebula located at a distance of 1,500 light years in the constellation of Gemini with an estimated diameter of 4 light years. The parent star, which will end up as a white dwarf, is believed to be the 16th bluish star near the center of the nebula, marked in the photo as PK205+14.1
This planetary nebula represents the end of the evolution of low-mass stars similar to our Sun. As these stars transform from red giants to dwarf stars, their outer layers are thrown into space, leaving behind a planetary nebula. Ultraviolet radiation, coming from the blue star in the center of the nebula, is responsible for the nebula's brightness.
115 images of 5 minutes each with Antlia Ha-OIII filter and 9 images of 5 minutes each with Antlia triband RGB filter.
Mewlon 210 tube with 0.8x reducer
QHY 168C Camera
Processed with Pixinsight
Bortle 8
This page or operation is not available at the moment, because AstroBin is in READ ONLY mode. For more information, please check out our Twitter feed: https://twitter.com/AstroBin_com
This feature is only offered at higher membership levels.
Would you be interested in upgrading? AstroBin is a very small business and your support would mean a lot!
This feature is only offered at the AstroBin Ultimate membership level.
Would you be interested in upgrading? AstroBin is a very small business and your support would mean a lot!
Only group members can post in a group's forum.
Please join or request to join the group, and then you'll be able to post a new topic.
If this user has been harassing you, and you shadow-ban them, all their activities on your content will be invisible to everyone except themselves.
They will not know that they have been shadow-banned, and the goal is that eventually they will get bored while having caused no harm, since nobody saw what they posted.
This operation will reload the current page. If you have any unsaved information in a form, it will be lost.
You can also dismiss this window, and your operation will be applied at the next page navigation.
This operation cannot be undone!
When you report abuse on some content on AstroBin, the content will be hidden until a moderator reviews it. Abuse reports are anonymous and the content's owner will not be notified.
Please specify a reason for this abuse report.
Please note: The following tables are updated every 24 hours.
| Distinct awarded users | Total awarded images | |
|---|---|---|
| Image of the day | ||
| Top picks | ||
| Top pick nominations |
| 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 |
| 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 |
Please note: You are on a Free account, and when you delete an image, your upload counter does not decrease (unless the image is deleted within 24 hours of uploading it). The Free account is not a way to keep your most recent or best 10 images on AstroBin, but a trial period for you to decide whether or not a paid subscription is worth it. For more information, please click here.
The image will be permanently deleted and cannot be recovered. All its revisions will be deleted too. Are you sure?
You will delete all other revisions (if any), and the originally uploaded image, leaving the current revision as the final and only version of this image.
You will delete all revisions, leaving the originally uploaded image as the final and only version of this image.
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. |
This image cannot be submitted for the IOTD/TP consideration.
Reason:
You are not authenticated. Please log in.
| Status | n/a |
| Started | n/a |
| Astrometry.net job | n/a |
| PixInsight job | n/a |
| PixInsight queue size | n/a |
| PixInsight stage | n/a |
Comments