Eemian Globe

I've created a rotating globe modelled after the Eemian interglacial, ~125,000 years ago.

 

Eemian Globe

I've been using this model to illustrate a series of posts by Steve Brown on Skeptical Science:

http://www.skepticalscience.com/LIG2-1906.html

http://www.skepticalscience.com/LIG3-1207.html

My goal was to portray a plausible shape to the Eemian sea, which cut Scandinavia off from the mainland. While at it, I erased part of Florida (in case Eemian sea level reached the high estimate of 9 meters over current) and much of the deltas next to major rivers. Like all my projects, this is a work-in-progress and I invite comments and corrections.

jg

Circumhorizon Arc

My first circumhorizon arc:

 

 

I saw this at noon on Sunday, 8/21/11. The noon sighting is consistent with the description of this phenomena on Atmospheric Optics:

• colorful ice halo from cirrus clouds refracting the overhead sun
• location parallel to and near the horizon

jg

Star Party at Lake Skinner County Park, Saturday, 6 Aug. 2011

The Lake Skinner County Park is hosting a public star party. It is free, but you need to arrive after 7:00 pm when the normal entrance fee will be waived for this event only.  The star party is that the Park's amphitheater. A show begins at 8:00 pm and observing through the telescopes of the Temecula Valley Astronomers begins after the show at 8:30 (or earlier) and continues till 10:30 pm.

Primary targets will be the 1st quarter moon and Saturn and various star clusters of the summer Milky Way.

jg

Supernova update

Last weekend I had a chance to revisit the supernova in M51. I took a few photos before clouds obscured the view. Here is M51 with supernova marked by the arrow:

This is a very noisy image. It's a 5-minute exposure at f6.3 and 1600 ISO. I'm a little surprised that the supernova remains as bright as it is and that I recorded it this well in a single exposure through a 3-inch telescope.

I had planned to take several images and try stacking them, but I forgot to tighten the axis clamps on my mount, so this was the only picture that didn't have significant streiks for stars.

jg

A star blew up 37 million years ago, and we just noticed

The amateur astronomy community is somewhat aglow over the opportunity to see and photograph a supernova in the galaxy M51:

Galaxy M51

The little dot marked by the arrow in the second photo is the supernova. I took this photo using a Canon Digital Rebel SLR attached to my 8" schmidt-cassigrain telescope reduced to an F6.3 focal ratio. The photo is a 5-minute exposure at 1600 ISO, and the camera is a bit noisy at this speed. I did not guide the photo, hence, you'll see slight elongation of the stars.

Better photos, taken at longer, guided exposures, and then processed via computer, will appear all over the Internet. Though no where near the quality you may see, my photo illustrates two aspects:
1. It shows that any amateur can get a photo of a supernova, something that most of humanity has never seen, using a common camera with a slightly less common telescope and mount. For a few thousand dollars, you could have the same photograph.
2. My photo shows about what I saw when looking at the supernova on June 3/4, 2011, through a friend's 25-inch telescope. Very few people have a 25-inch telescope.

The irony is that right now, the more scientifically valuable contributions from amateurs are those images taken before the supernova. The amateur astronomy community is being asked for any images that can narrow down the time between May 30 and June 2 when the supernova first appeared. I took my first image of M51 one month ago, using a 3-inch telescope. I pointed my camera at M51 on a whim, just to see what I'd get. Here are the before and after:

For more information on contributing images of M51, see this post at Palomar Skies: amateur-astronomers-can-help-ptf-study

jg

A Good Day for Sundogs and Better for Halos

Where I live, May usually brings 90+ F degree days that makes seeing the rings and arcs from atmospheric ice crystals rare, but this May has been unusually cold , making for some great halos. I saw this one yesterday:

Colorful arc with ends that split on the left and right.

Lower center is my hat blocking the sun.

The lower section of the arc was not as bright nor as colorful.

My hat is barely shown at the top, where it is blocking the sun.

Most 22 degree halos I see have little color and are a single halo, rather than a split halo shown here next the sundog:

Sundog, outer ring, and inner 22-degree ring. The outer ring leads into the sundog,

suggesting some common optical property at work.

According to Atmospheric Optics, the sundog gets closer to the inner, 22-degree halo as the sun is lower to the horizon. These photos were taken around 3:30 PM, when the sun is still rather high in the sky, and accordingly, the sundog is noticably out from the 22-degree ring.

This ring was also observed by a friend and fellow sky-watching enthusiast who took this photo, probably a mile from me:

Photo by Shaun Brodie

Shaun's photo is a bit more useful in that he included the sun, from which we can trace the arcs of the two rings. Shaun duplicated and rotated his photo to create an extension of the ring. He manipulated the contrast and then drew the approximate tangents that conform to the outer ring.

According to Shaun, "The center of the secondary arc lies on the circumference of the arc/circle around the sun." I took a slightly different approach and agree with his conclusion:



An update(24 May): Per Atmospheric Optics, the outer ring is a circumscribed halo, which is also the high sun version of the upper and lower tangent arcs:
Circumscribed halo

Keep looking up.

jg

I guess this is what you do on blogs

Whenever one corresponds via others' blogs, and the correspondence leads to discussion, controversy, and vitriol, one provides links. I'm not sure if I'm getting my vitriols yet, but there's still time.

I've been following a local blogger and satirist since discovering 1) he can be funny, 2) he leaks the views of a former council member whose civic knowledge I respect and admire, 3) he has shown some pro-city, pro-community attitudes, and 4) he offers a contrary opinion. Though sometimes I've applauded the contrary opinion, often I don't agree. Regardless, I enjoy hearing it, and I have a scientific curiousity about people with contrary opinions.

Since he's outed me as a reader, I'm committed to the quality of his blog. So it was in this spirit I commented on his interview with an activist whose litigation overturned a $28-dollar yearly assessment for the maintenance of our community's parks:
The Provocative Interview

Having participated in the reopening of parks through my position on a redevelopment committee and through other community activities, I took umbrage to the portrayal of our local litigant's motives and his characterization of members of the Parks Committee. My rebuttal is here:
My response

Our litigant replied to my statements here:
The interviewee's response

And I'm awaiting the posting of my rejoinder which I'll share (when posted).:

Me again (17 May 11)
My May 17 comment is reproduced below

Steve's explanations are consistent with what I observed, and I was careful to qualify my inferences as inferences. We can't know the thinking behind others' overt behavior. (Is everyone with me on this?)

I struggled to not let later events rewrite my memory (e.g., Steve's opposition to incorporation and to the parks assessment). I hope Steve has exercised similar scrutiny.

Regarding Steve's humor, which I enjoyed:

Steve: The neighborhood where I live is named “Parkside” Estates, not “Collegeside” Estates – enough said.

I sympathize with this. "Parkside" does imply there would have been a park. I welcome any advice on how I can contribute to making that park a reality, seven years ago as well as today. Regarding "Estates" I trust that part of the name has met Steve's expectations, as there's nothing I can do there.

Considering Steve's presence in Wildomar politics, I welcome any public record of his efforts to make the park of Park Estates a reality. I'm inclined to believe that he has made the statements I seek, but I ask because I'm undecided as to whether breaking up the parks assessment was a means to that end or intended as a punishment.

Steve raises a good question about the RDA and Marna O'Brien:

Steve: I am informed that the good people of Lakeland Village are still trying to figure out how millions of dollars of RDA funds legally mandated to be used to combat blight conditions within their RDA boundaries were used instead to refurbish Marna O’Brien Park, which is not even located within the Lakeland Village Wildomar Redevelopment Project Area. Perhaps a future expose for Zak Turango?

Actually, our minutes are public record, so anyone "still trying to figure out how [money is spent]" may be not worth reaching out to, but I'm willing to help. And, I did offer my help, as a member of the RDA, to Steve at our first meeting. I was willing to see if the RDA had any means to assist in his dispute. The RDA has since used its voice on other issues in the community. That Steve would suggest an expose reveals more of him than it will of the RDA.
Let's put forth a testable hypothesis. I may be an idealist fool or Steve may be working too hard to find fault in collective action. (Actually, I admit to being an idealistic fool, but the question is whether it's to an extent that is detrimental to the community.)

The RDA committee I'm on was elected so that the community can have a say in what is considered blight and in how to correct it. We decided that shuttered parks were a condition of blight (which raises the question of who is fighting or promoting blight).

Marna O'Brien is a half block beyond the RDA boundary. However, the RDA can invest in projects outside of its boundary if such projects benefit the RDA. For example, we are reviewing sites for a new fire station that will service the RDA zone but likely reside outside the boundary. If this is inappropriate, it's not too late for citizens to intervene. (Before you answer, please know that if there were a fire outside the RDA, I'm Ok if you want to call the station we'll have paid for.) The same can be said for community centers, flood infrastructure, roads, signals, and even the water quality of Lake Elsinore.

But back to the park... RDA residents near Mission Trails drive southwest to reach Marna O'Brien; RDA residents near Central drive northwest; and those near Grand drive northeast. We have the park surrounded! (See map.) A park with Marna O'Brien's services is a benefit to the RDA and the greater community. Forgive the cliche but we all rise together -- but I guess we can add "fail together, too"

If there is a flaw or violation in the RDA's support for Marna O'Brien, please charge ahead and investigate, but make sure you can get the whole story before undermining people's confidence in collective action. I'm available to anyone who wants to know more about the activities of the RDA since I've been a member.

jg

And the map I sent is here (click to enlarge):