Tuesday, June 21, 2016

A New Astronomical League Bright Nebula Program Object List: Getting Better, but Not Good Quite Yet

Finally! A New version of the AL Bright Nebula Program list.
  • It's brighter--all the dimmest objects are gone
  • It's clearer--most of the seemingly conflicting objects are gone
  • It's buggy--there are a lot of duplicate items and typos, and a few head-scratchers remain


After almost two years of letting the Astronomical League's Bright Nebula Program suffer with an object list that was confusing and somewhat buggy, a new version is out. While the new list has some improvements, it continues the legacy of errors found in early versions.

Errors that should have been caught include:
  • Six objects are on the list twice
  • There remains one object on the list that is known to be a catalog error. (Is this intentional?)
  • One object's existence is disputed (NGC 1990: is it a reflection nebula or simply glare?)
  • Some designations are simply wrong. Examples include: Pickering's Triangular Wisp is given an NGC number that belongs to a galaxy; apparent typing errors assign incorrect catalog numbers to the western branch of the Veil, Struve's, Running Man, Eta Carinae and Barnard's Loop nebulae
  • Unlike earlier versions that were ordered by RA, the new list appears to have been left in random order
  • Two entries are given the same index number of 116

It's as if the list was never reviewed or proofread. It's definitely not up to the AL standards to which I've grown accustomed.

One upshot of the errors is that there are actually only 143 or 144 objects (depending on whether the disputed object is retained) in a list that is claimed to have 150 objects.

Despite its smaller size, the new form of the program is much easier to complete. Gone are the objects in Lynds brightness categories 5 and 6. Most of the 4s have been dropped, too. There are also fewer objects so far south that they're unavailable to northern observers/imagers. The loss of objects is countered with a lot of new reflection nebulae; these won't be all that easy to image from urban locations, but my guess is that they're not as difficult as imaging Lynds brightness 5 and 6 objects.

Other improvements long overdue are the resolution of some of the problematic designations like NGC 6526. The confusing object assignments for the Cat's Paw, Gamma Cass, Heart, Butterfly, and Pelican nebulae areas have been dealt with. There's still an issue with the Seagull, but progress has been made.

The list difficulty is so different now it will be interesting to see if the award numbering system is reinitialized. On a related note, the certificate number I have on paper continues to be different from the one the AL reports on its web page. I doubt it will ever be fixed.

One final comment: It would have been nice if the program coordinator had thanked those of us who completed the old form of the program and essentially acted as beta testers.

I'm currently working on a corrected object list that will be in PDF and spreadsheet formats. I'll post a download link here as soon as it's ready.

Sunday, June 5, 2016

Sharing the Back Yard

I live in a second-tier suburb south of Minneapolis. About a mile away is the Minnesota River valley, a broad expanse that's been kept relatively undeveloped. One might expect to get a lot of wild visitors from the valley, but seldom has anything out of the ordinary been observed. Aside from deer that have been seen only two or three times in over 30 years, it's the usual suburban mix: Owls, rabbits, and raccoons (although their numbers seem to be greatly reduced in the last 20 years or so).

Increasingly present are species that are reclaiming old territories. Bald eagles have become frequent visitors. There's a giant old cottonwood tree in an adjacent lot that someday could play host to a nest, but it might be too far from the river. "Location, location, location," applies in the animal world, too.

Coyotes are also returning. I've heard them howling nightly at most star parties in the open country but now they're back in the suburbs. I've gotten a few glimpses of one trotting quickly away in the last few years, and this spring I've seen one that seems more at ease. Twice it's been seen sleeping on the back yard lawn at the sky brightens at the end of dawn:

The gleam in its eyes is from the flash, not radioactive waste! This one seems more at ease with its surroundings; It showed only mild interest in people walking a few hundred feet away.

Looking perfectly at home
Starting the morning commute
There's no shortage of food available to it. All sorts of rodents are on the menu: Rabbits, squirrels, and shrews are in abundance this year. Add to that all the pet cats and small dogs that are allowed to roam outdoors and I doubt the coyote will go hungry. (Our cat is an indoor cat.)

Bobcats have also been sighted in the river valley and I'm really not eager to see one in my back yard. I consider them much more likely than a coyote to go after larger prey like an imager.

The Minnesota river feeds into the Mississippi river a few miles downstream from here, and together they form a natural impediment to animals traveling southward. Black bears, not all that uncommon in the northern areas of the Twin Cities do occasionally make the trek southward. Two years ago a black bear made it "south of the river" and roamed for a few days through this area. Only the wayward bear came to harm; it was shot in the leg by a police officer and may have survived to return north.