Michael A. Covington    Michael A. Covington, Ph.D.
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Daily Notebook

Popular topics on this page:
3 kinds of political foolishness
Supermoon explained
How to get accurate news
The N-1 standard deviation
What to wear to church

Moon (perigee vs. apogee)
M15 (globular cluster)
M33 (Triangulum Galaxy)
M33 (Triangulum Galaxy)
M42 (Orion Nebula)
M52 and nebulae
NGC 752 and galaxies
NGC 6822 (Barnard's Galaxy)
NGC 7293 (Helix Nebula)
NGC 7331 and Stephan's Quintet
vdB 133 (44 Cygni)
Sagittarius star cloud and nova
Veil Nebula
Many more...
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Pleiades at even greater length

The rest of November is going to be busy, so I'm uploading this entry early (November 27). See you in December!

Here's an even longer (total) exposure of the Pleiades, showing the dust clouds and their strange streaks and stripes. Stack of 50, yes, 50 1-minute exposures, AT65EDQ telescope, Nikon D5300, taken in my back yard on a rather clear night.

Orion Nebula in HDR

The Orion Nebula, same technique as above, but only 32 exposures stacked, and the picture was processed with the HDR Multiscale Transform in PixInsight to bring out detail. The process is: do the nonlinear stretching, but do it half-heartedly so that little or none of the picture reaches maximum white; run HDR Multiscale Transform; and then do a little more nonlinear stretching to boost contrast.


M33 splendor

You've seen this galaxy before, but not quite this well. This is M33, in the constellation Triangulum. I showed you another photograph of it earlier this month. This one, however, was taken at Deerlick. Stack of four 5-minute exposures, Canon 300-mm f/4 lens at f/5, Canon 60Da.

And that concludes the series of pictures I took at Deerlick on October 28 and 29.

Who remembers June 4, 1978?

There was a hiatus in my early activities as an amateur astronomer, and as a result, a striking phenomenon snuck up on me.

I was an avid amateur astronomer from 1968 to 1973 and again starting in 1979. For a while during my college years, though, I didn't follow astronomy.

As a result, when I was standing in Memorial Court at Clare College, Cambridge, on the evening of June 4, 1978, I was at first not able to tell my fellow students which two planets were so close together in the sky.

It was Mars and Saturn, and they were less than a tenth of a degree apart.


M52 and nebulae

Here is the star cluster M52 in Cassiopeia and its surroundings in a rich field of the Milky Way, including some nebulae, which show up red. Stack of five 5-minute exposures, Canon 60Da, Canon 300-mm lens at f/5, AVX mount with autoguider, taken at Deerlick on October 29.


Veil Nebula

Before November is over, let me get back to showing you last month's astrophotos! This is part of the Veil Nebula or Cygnus Loop, a supernova remnant. Stack of ten 5-minute exposures with Canon 300-m f/4 lens, AVX mount, and Canon 60Da, at Deerlick on October 28.

This is a nebula that photographs in different colors with different cameras because it emits so much blue hydrogen-beta light as well as red hydrogen-alpha. This camera (the Canon 60Da) has lots of response to red. Other DSLRs ender the same nebula blue.

Fidel Castro

Fidel Castro has died.

In 1973 I turned down an invitation to meet him. He was making a state visit to India and staying in the Ashoka Hotel. I was in the same hotel with a student group. I got in an elevator that already contained 2 well-dressed men who were speaking Spanish and standing close to the control panel. As they looked politely toward me, I said, "Número siete, por favor" (my floor number). They were startled to hear their native language and immediately introduced themselves to me in English. They were part of Castro's entourage and invited me to come meet him.

I turned down the invitation because I was on a National Science Foundation-sponsored trip and figured I ought not to do anything that might lead to publicity without checking with our leaders. I could just imagine my picture appearing in Granma (or even Pravda) and spoiling my chances of getting a security clearance forever.



What to wear to church

This entry is mainly for my Christian readers, but it may interest some nonbelievers who are going to visit a church during the holidays, or who just want to know what we think about such things.

Our pastor, David Mills, recently shared this essay by Thom Rainer, which obviously addresses only one part of a complex picture. Here are my thoughts on the whole picture.

I'm glad one of the rituals of the 1960s is dying out. When I was a child, "dressing up for church" was a serious stumblingblock for me. The jacket and tie were uncomfortable. If I could have dressed for Sunday School the way I did for regular school, I would have been a lot more willing to go. My Catholic friends opened my eyes to the fact that one can go to church without "dressing up." They have so many other rituals that they didn't feel a need to make a ritual out of getting dressed.

The church that I attend conveys a message that diverse kinds of attire are acceptable. The pastor wears a suit; the musicians don't. I didn't have comfortable suits until, as an adult, I was willing and able to spend enough a lot of money on them. But I don't wear them to church because I think they're a bit fancy for that. Also, and more importantly, I choose not to wear a tie because I don't want less well-dressed people to feel left out or unwelcome.

I think the strong emphasis on "dressing up for church" in previous decades goes back to the days when most Americans were farmers. For a farmer, Sunday morning is welcome relief from having to wear work clothes — at least until something needs tending or feeding later in the day! But modern city dwellers are dressed for reasonably dignified indoor activities every day. They don't see the immediate need to wear something different to church.

What about the notion that you should wear your best to honor God? Well, that's a good idea as far as it goes, but it doesn't go very far. 1 Samuel 16:7 makes it very clear that your outward appearance cannot impress God. In 1 Timothy 2:9, St. Paul warns people to dress modestly and simply. And so on.

"Wear your best for God" rose to the level of a folk doctrine (or heresy) fifty years ago, and I think it impeded the church's mission. (It almost got rid of me!) Obviously one must strike a balance. We do want to show our respect, but that's not the same as showing off. Don't forget that suits, ties, and nice dresses are secular status symbols or even ways to show off wealth. (Among people who only wore them to church, this point often became blurred!)

Then there are women who have had it ingrained in them that "every woman should always look her best" as if that were a biblical commandment. Much as I like beautiful women (1 wife, 2 daughters, 2 granddaughters so far), I don't want them to think God made them primarily for eye candy. That's a serious step down from what God meant them to be.

If asked, I would say that churchgoers should avoid clothes that are positively undignified (e.g., shirts with derogatory writing on them) and women should not dress provocatively (this includes brides at their own weddings!) but apart from that, just dress for an orderly indoor activity. And I would say to any fellow Christian that if you think your clothes will impress someone, or that you will look better than someone else, it's time to tone it down.

And I would urge extreme tolerance for people who dress differently. You never know what might prevent them from dressing more elaborately (maybe they're traveling, or poor). And at the other end of the scale, I wouldn't take away my friend's 3-piece suit — it's his tradition — it's what he's used to — just as much as my tweed jacket is for me.

Addendum: Clearly, two things have to be balanced, (1) looking respectful, and (2) avoiding vanity and exclusiveness. In my childhood, (1) had displaced (2). In some churches, (2) has probably displaced (1). To my friends who wish everyone dressed better for church, I recommend leading by example, but never looking down on or rebuking someone who does not dress as well for church as you do.

If you're going to visit an unfamiliar church, click here for a helpful FAQ.



We're having a rather low-key holiday season this year because Melody is suffering from mechanical failure of an implanted hip joint, caused by infection, and can barely walk with a walker. But we do have things to be thankful for this year. Most importantly, Sharon is getting relief from the nerve injury that has plagued her for five years. And we have a schedule for getting Melody better; after two operations, she should be walking by the end of March. Business is booming, and we have four thriving grandchildren!

What we don't have is a lull in activity, the way we used to when I was in academia. If anything, I have as much work to do this month and next as I've ever had. I don't mind; that's what I went into business for.


Hasty news update

I haven't disappeared — but haven't written much, either. I have lots of consulting work in hand; I'm even making a potential client wait; and I'm scrambling to make up time lost while I was skirmishing with toothaches a week ago. My tooth came through the root canal procedure just fine and will be crowned next month. (A root canal doesn't hurt. What hurts is needing one and not having it!)

Melody has 2 hip operations coming up and is presently scheduled to be in the hospital over Christmas, though the dates may be changed. Your prayers are appreciated. What we are thankful for is that now we know what the problem is, and we have a schedule for correcting it.

Back soon.



Here you see the Pleiades star cluster, with plenty of the reflection nebulosity (dust) that surrounds some of the stars and is pulled into a streaky pattern by the stars' magnetic fields.

I wasn't expecting much from a picture taken through hazy skies, with the moon rising. This was basically an autoguider test, but I did come out with a presentable picture. Stack of 10 2-minute exposures, AT65EDQ telescope, Nikon D5300.


It's full of forest fires!

Tennessee, South Carolina, and the northernmost part of Georgia are full of uncontrolled wildfires thanks to an extreme drought. That's why I haven't photographed any celestial objects fainter than the moon for a while. There's a strong smell of smoke in the air, and we are advised to limit our time outdoors. In fact, a few times, a whiff of the smoke has gotten into a building unexpectedly, and I've found myself looking for something on fire.

If you don't know how bad it smells, the smoke does add to the picturesqueness of autumn, complementing the leaf colors and the elegant architecture of the UGA campus. Here's an example:

There is not normally any visible haze in front of buildings viewed from across the North Campus quad.

My tooth is behaving itself thanks to antibiotics and rest, and my root canal procedure is tomorrow morning (Nov. 17), followed by a crowning (coronation?) a couple of weeks later. And scrambling to catch back up with work!


Bessel's correction, or the N-1 standard deviation

Sometimes I write a Notebook entry just to get my own thoughts in order about something; this is one of those times.

It has come to my attention that R always computes standard deviation as

√[(1/N-1) ((x1 - mean(x))2 + (x2 - mean(x))2 + (x3 - mean(x))2 ... )]

and not the formula we remember as the definition of standard deviation:

√[(1/N) ((x1 - mean(x))2 + (x2 - mean(x))2 + (x3 - mean(x))2 ... )]

I remembered that the N-1 standard deviation (that is, the first formula) was traditionally used for the standard deviation of a sample that estimates that of a larger population. But what's going on, exactly?

There are many longwinded explanations in books, but the key idea is that if you use the second formula, and you are indeed analyzing a sample of the population, your estimate of its standard deviation will be too low...

...because you're using the mean of your sample rather than the mean of the whole population. And the mean of your sample is necessarily closer to the values in your sample than the population mean would be (unless by some chance it happens to be the same).

The astronomer F. W. Bessel came up with the idea of using N-1. There are proofs that this makes the estimate of the variance unbiased (that is, although it is not a perfect estimate, it is no more likely to be too low than too high). The standard deviation is the square root of the variance, and Bessel's correction does not result in an unbiased estimator of the population standard deviation because the square root is nonlinear, but it helps.

Doug Downing and I are both rather mystified that R insists on using the N-1 standard deviation exclusively, with no built-in function to do it the other way. That's just wrong when you're summarizing an entire population. Particularly in signal processing, the N standard deviation (the RMS value of the signal) is often needed. We're puzzled.

Time out for a tooth

I remarked a while back that, in international relations and in medicine, every crisis has its own timescale.

In the case of my toothache, I went to the dentist one day too early, with diffuse soreness all over my gums, and all he could diagnose was a diffuse irritation of the gums. The next day, when I went back, the gum pain had all gathered in the vicinity of one tooth that was known to have problems. What's more, that tooth had lost its long-standing sensitivity to heat and cold, and after going through a day or two of seeming good health, acquired a new kind of sensitivity to pressure, almost as if it had been hit hard and almost knocked out and was then settling in again.

So it's "irreverisible pulpitis." The infection has killed the nerve in the tooth and started to come out through its root.

I'm getting a root canal on Thursday morning, and the tooth will get a crown a few weeks later. In the meantime, it's responding to an antibiotic. I'm taking a day off work to gather my strength — I have germs to kill!


My supermoon experience

The closest lunar perigee of my lifetime is noteworthy, and it occurred at 6:24 a.m. EST on the 14th, as measured from the center of the earth. My own closest pass to the moon, however, happened around midnight on the evening of the 13th, because at midnight, you're on the side of the earth that is turned toward the moon.

At that time I was closer to the moon than I have ever been before. I went outside and looked up. The moon, high overhead, did look a bit bigger than usual. The sky was gray with haze and smoke from wildfires in the mountains, so the stars were almost not visible, although I could make out Orion. The bright moon dominated everything.

Earlier, around 9 p.m., I took pictures with my trusty old Celestron 5. One of them completes an illustration I had been planning for a while:

The other is just a picture of the nearly full moon, with the color slightly enhanced:

Each (including both halves of the first one) is a stack of six still images taken with a Canon 60Da. They were cropped and binned 2×2 with PIPP, then stacked with AutoStakkert 2, then sharpened and postprocessed with Photoshop.



How to get accurate news

It's not just what media you read, it's how you use your mind.

"You can't trust the media" was a watchword during this election season. Unfortunately, it left a lot of people with the confused impression that the news media are just fiction — that they are not reporting reality at all. Not true. There are good ways to get accurate information. I'm going to outline a few of them. What I say is very basic, but even so, the word needs to be spread.

(1) Make up your mind that accuracy is what you want. That is crucial. If you aren't cultivating a habit of truthfulness in your own mind, you'll never have a good grip on the truth.

If what you really want is a thrill of anger, or a set of illusions that support your beliefs, then that's all you will get. The truth it out there — and it is often strangely dull. It doesn't cater to your emotions.

"I only read conservative news sites" or "I only read liberal news sites" — those are the slogans of people whose first priority is opinion, not truth.

(2) Go for information, not entertainment. Let's face it, the Fox and CNN web sites are more entertainment and commentary than news these days. I get a good bit of my news from Reuters, which is somewhat duller, and from the BBC. Neither of those is perfect, but they do hold themselves to a high standard.

(And don't forget how much good information you can get straight from the horse's mouth. If you want to know what the Trump campaign is saying about something, how about going right to their own web site, the way journalists do?)

(3) Distinguish hard facts from interpretation and speculation. For example:

"Trump says he wants to repeal Dodd-Frank" — That's a hard fact. Either Trump said this, or he didn't, and if he didn't, nobody would be reporting that he did.

"Trump supports big banks" — That is interpretation. Trump is doing some things that someone interprets as support for big banks. The news story should say what he's doing, but it's up to you to decide whether the interpretation is correct.

"Trump may cause another financial crisis" — That is speculation. It's just someone's opinion. If it's a well-informed opinion, it might be worth listening to, but it's not news. It is not a hard fact or set of hard facts.

Hard facts are actual, confirmable events that anyone with accurate information should agree on. They should be able to be confirmed by more than one source.

(4) See through the interpretations and extract the hard facts. That's my secret weapon. Even when reading a heavily interpreted story, I look through it to see what the hard facts are.

For example, the Washington Post was obviously anti-Trump, but they weren't reporting pure fiction. They were reporting real events and putting their interpretation on them. With this in mind, it's not hard to extract the real events and discard or question the interpretations.

Another good tactic is to ask, What is the other side of this story? For example, Fox reporter Todd Starnes often reports one side of scandalous events and situations. What is he not telling us? If a news source doesn't tell you both sides of a story, ask yourself what the other side might be and seek information from other sources. That doesn't mean both sides are equally good; the situation may still be scandalous; but you shouldn't be ignorant of the other side.

(4) Use multiple sources. If something really happens and is important, multiple sources will confirm it. If you see something on only one web site, be skeptical. Somebody may be mistaken.

(5) Beware of fakers. Remember that any crank can create a web site with "news" in its name and take (or steal) a picture of a well-dressed announcer under a "Breaking News" banner. Some of them steal pictures from real TV networks and tell you the picture shows something it doesn't.

(6) Above all, strive to be a fair-minded person, not eager to believe evil. C. S. Lewis asks us to imagine what we would do if we heard of something scandalous, and then, later on, got better information indicating that the scandal was not as bad as it first appeared.

A good person should be relieved that something is not as bad as it could have been.

But many people would be disappointed instead, because they wanted a juicy story. Lewis says to beware of such a mindset — wanting to believe things are worse than they really are — because it leads to a black state of mind in which you want to believe that everything is bad.

And I think we have all encountered people in that black state of mind.


Supermoon explained

You've heard there's a "Supermoon" Sunday night (Nov. 13). Here's what's going on.

The moon's distance from earth varies because the orbit of the moon around the earth is not a perfect circle. It doesn't need to be; Newton's theory of gravity says that orbits are normally elliptical.

The apparent size of the moon varies this much:

(These pictures were taken with the same telescope and camera.)

The moon reaches perigee (minimum distance) and apogee (maximum distance) every month. These do not coincide in any regular way with the phases of the moon. Because the phases of the moon depend on the direction of the sun, and perigee and apogee don't, you can have perigee or apogee at full moon, new moon, or any phase in between.

But on top of all that, the shape of the ellipse varies because of the sun's gravitational pull. That means the minimum distance is smaller at some times than others.

That brings us to Monday, November 14, at 11:24 UTC, which is 6:24 a.m. Eastern Standard Time. That will be the closest perigee since 1948, measured from the center of the earth. (The moon is closest to the part of the earth where it is high overhead.) The moon will be nearly that close for about a day either side of that time.

It happens that the exact moment of full moon is about two and a half hours after that. Perigee and full moon need not coincide, but this time they do. That's what they call a supermoon — a perigee full moon.

Of course, we can only see the supermoon when the moon is in the sky, and the full moon is in the sky all night and none of the day, so in America we will see it on Sunday night.

Should you go out and see it? Well, it's a perfectly normal full moon except that its apparent size is a few percent bigger than average. Sky and Telescope suggests making a handheld gadget that you can hold at arm's length to measure the apparent size of the moon, then trying it again some time when the moon is not at perigee. No telescope is needed.

Don't confuse the supermoon with the moon illusion, a familiar optical illusion that makes the moon look bigger when it is seen against trees or distant buildings than when it is high in the sky. By taking pictures of it in both situations, you can show that the moon illusion is an illusion. On the pictures, the moon will be (very slightly) bigger when high overhead.

To photograph the full moon, use a telephoto lens (or zoom out as far as you can) and put the camera on a tripod and use delayed shutter release to minimize vibration. With a DSLR, focus manually using Live View; autofocus isn't precise enough. If the camera isn't a DSLR, set the focus to infinity (the mountain symbol).

Then, when you have the picture, try Unsharp Mask in Photoshop to bring out detail.

And go back and photograph the full moon again in May or June, when it's near apogee and will look significantly smaller.


A point of politics, morality, and theology

The outcome of an election is not just a winner; it is a distribution of votes, indicating how severely the people are split and what they are split between.

With that in mind, what's best for the country, in any particular election, is surely a distribution of votes, not a unanimous winner. We do not normally want people to be elected unanimously. It would lead to overconfidence and poor government.

It follows that people who vote differently can all be doing what's best for the country. I seem to recall a time when this was common sense. Let all the voices speak, and listen to as many of them as possible.

For my fellow Christians, now, replace "what's best for the country" with "the will of God." I do not think God normally "anoints" one candidate and wants that person elected unanimously. And if the will of God is a distribution of votes, it follows that people who are perfectly doing the will of God need not all vote alike.

Let's remember this as we try to recover from this traumatic election.


NGC 7331 and Stephan's Quintet

It is appropriate to photograph NGC 7331 from Deerlick because of a complex chain of naming. A while back, Tom Lorenzin observed NGC 7331 and the galaxies near it (close, much smaller, and to the left of it in the picture) from Deer Lick Gap, North Carolina, and named it the Deer Lick Group. (In a quick online search, I can't find exact records of this.)

Then a group of my fellow Georgians dubbed themselves the Deer Lick Group and founded the Deerlick Astronomy Village (without a space between Deer and Lick). And that's where I took the picture.

At the lower right is another cluster of galaxies, Stephan's Quintet.

Stack of five 5-minute exposures, Canon 300-mm lens at f/5, Canon 60Da, AVX mount and autoguider.


One short remark about the election

Both presidential campaigns were very negative, designed to frighten people about the dire consequences of electing the other candidate. They succeeded. Everyone is frightened and angry.

A second confounding factor is that a great many voters felt that both candidates were bad, but one was not quite as bad as the other. To such a person, winning is almost as frustrating as losing. Some don't understand their own frustration and are looking for another target for it.

That is also why the polls didn't work. "Lesser of two evils" is a kind of political position that polls aren't designed to pick up. Many people who felt they were voting for the lesser of two evils probably did not reveal their preference to pollsters at all.

As the transition to the new presidency unfolds, my advice to my fellow citizens is to pay attention to real events, not speculations about what might happen, and not to give undue weight to rare isolated incidents.

Barnard's Galaxy (NGC 6822)

This irregular galaxy is relatively nearby and was the first galaxy whose distance Edwin Hubble estimated using variable stars. In a sense, it was the first galaxy to be discovered — the first "stellar system" that was shown to be so far away as to be unconnected to our own.

Stack of nine 5-minute exposures, Canon 300-mm lens at f/4, Canon 60Da, AVX mount. Along the top of the galaxy, you can see a couple of its own nebulae (H II regions), which look almost like bluish stars. They show up bluish because they are strong in hydrogen-beta light.

Helix Nebula (NGC 7293)

This object is much closer. It is the Helix Nebula, similar to the Ring Nebula but much closer (700 light-years). It consists of gas blown off by its central star, and my understanding is that it's not really a helix, just a ring with one side somewhat bashed in by interstellar gas.

Stack of four 5-minute exposures, Canon 300-mm lens at f/4, Canon 60Da, AVX mount.


41 years

Today is the 41st anniversary of the day Melody and I met at a University of Georgia recruiting event. I've told the story in more detail elsewhere. Unlike most of the prospective students, she arrived unaccompanied by parents, siblings, or other entourage. I saw my duty to the University and did it. I recruited her, shall we say, successfully.

We didn't start dating until May of 1976. In retrospect, I don't know of a good reason for the delay, except that God makes things work with His timing. We were together as undergraduates at UGA in 1976-77, and then we had a long-distance relationship for five years while I was in graduate school. We survived almost six months of not seeing each other during my last two terms at Cambridge, from January to June 1978, and by then we were sure that nothing could separate us.

What I want to add to the story today is something we've been reflecting on. My main thought in our early days was not "What a nice girlfriend I have," but rather, "Now there are two of us!" I didn't think of her as an acquired girlfriend but rather as my best friend or even second self. (Amicus est alter ego, says the Latin proverb.) What followed was not courtship so much as the gradual merging of two lives. For some people, marriage consists of finding an attractive person, marrying them, and then trying to get to know them. Not us!

Part of the background is that by late 1975, both of us had become aware that it might be all too easy to acquire an unsuitable girlfriend/boyfriend, an admirer who is not actually a good long-term companion, even though they think they are. Melody was, for me, totally different from all the other girls in the world. And she has assured me that part of my function in 1976-77, even though I didn't know it, was to scare off other admirers!

Today Melody has found out she is going to have to have at least one and possibly two more hip operations, to correct a failure of the hip implant that was put in two years ago. Your prayers are appreciated.

A co-valedictorian and the genetics of aging

Another point of contact with the 1976-77 school year occurred yesterday. In 1977, UGA had two co-valedictorians. I was one; the other went on to become the eminent geneticist Cynthia Kenyon. Yesterday she was back, to give the Charter Lecture, and I went to the University Chapel to listen.

The key point of the lecture is that aging is a biochemical process. We know this because there are genes whose expression or non-expression speed it up or slow it down. (We see one of these in dogs; big dogs have a shorter lifespan than small dogs.) Most intriguingly, sperm and egg cells have to be factory-fresh, so to speak, regardless of the age of the animal producing them, so they won't produce a prematurely aged baby, and there is a biochemical process for removing aging-related damage just before fertilization. With all of this emerging biochemistry, it's quite possible that we will soon have medications that extend our lifespan (and our span of good health) by acting on the aging process directly.

The research is done mostly on worms with a 2-week lifespan. Obviously, if you use any animal that lasts much longer than that, it takes too long to do the experiment. In fact, one reason so little is known about human aging is that it takes 70 years to see the effects of any change!

Although Cynthia and I were exact contemporaries, we did not know each other in college, so our prior acquaintance was confined to the graduation ceremony. I'm pleased to say she recognized me, with some difficulty, despite having no indication that I'd be coming. Apart from that, there didn't seem to be any mutual acquaintances in the audience, except for one, John Barrow, the former Congressman.

Her valedictory speech in 1977 was about the divide between North Campus (humanities) and South Campus (sciences). Talking with her and recalling that speech, I explained that I had been a student on North Campus and came back as faculty on South Campus; in fact, a good description of my early academic career might be scientist in humanist's clothing (defining "humanist" as a scholar in the humanities, not a person who accepts Humanism as a philosophy).

Like me, she has retired from academia in order to work in industry. It seems to be the thing to do.


The nebulous neighborhood of 44 Cygni

Last month I noticed, a photograph taken from Athens, that the star 44 Cygni is surrounded by a reflection nebula. On October 28 I got to Deerlick with my Celestron AVX mount, Canon 300-mm lens, Canon 60Da camera, and, most importantly, the STV autoguider and miniature guidescope, enabling me to take long exposures. Here's the region of 44 Cygni, a stack of five 5-minute exposures:

You can see that 44 Cygni is surrounded by white reflection nebulosity. The reflection nebula is known as van den Bergh 133 (vdB 133). To the upper right you see the small, bright red emission nebula Sharpless 2-106 (Sh 2-106).

Neither one was observed with telescopes in the 19th Century, so they don't have NGC numbers.

If you click on the link, you will see that van den Bergh catalogued reflection nebulae around "BD and CD stars." By that he meant stars listed in the Bonner Durchmusterung and Cordoba Durchmusterung, star catalogues of the time. When he was doing his research, the SAO Star Catalog (1966) was not yet available.

By the way, I learned that Simbad was not incorrect to equate VDB 133 with 44 CYG (that's how they write them). By policy, in Simbad, if a reflection nebula has one star in it, the nebula and the star are treated as the same object.



A star cloud with a nova

OK, here's the third Notebook entry today. I have a lot of pictures to catch up on processing and sharing!

Taken under the dark skies of Deerlick on October 28, here's a picture of the star cloud right at the "spout of the teapot" in Sagittarius. The star near the bottom edge, right of center, is Nash (Gamma-1 Sagittarii). In front of the star cloud you can see two prominent small dark nebulae (dust clouds). Stack of six 1-minute exposures, Canon 300-mm f/4 lens, Canon 60Da, Celestron AVX mount.

Now for a detail. Near the center of the picture is an 8th-magnitude nova, indicated by the arrow below. This is the star tentatively designated TCP J18102829-2729590. This designation suggests that it has not been confirmed to be a normal nova, or else its designation would at least start with PNV, becoming eventually something like Nova Sagittarii 2016 No. 3 (or 4, or however many we're up to).

It used to be thought that novae were exploding stars. The current view is that novae are pairs of stars orbiting each other so close together that the smaller star is occasionally able to "refuel" itself, grabbing matter from the larger star and greatly increasing in brightness. This is indeed an explosion, and it can even drive off an appreciable amount of gas into space, but it doesn't destroy the pair of stars, and they can do the same thing again a few years or centuries later; RS Ophiuchi has been seen flaring up 6 times. Stars that blow themselves to bits are supernovae, a much rarer phenomenon.



It's full of stars!

Continuing to present my recent astrophotos least-spectacular-first, and moving backward through time like Merlin, let me show you the two most recent. I was testing PHD2 Guiding software with my DMK21AU04 camera and a tiny homemade guidescope. Because of the prolonged test, I ended up making ten, count 'em, ten 5-minute exposures of the star cluster M34 with my 6.5-cm f/6.5 refractor, Nikon D5300, and CGEM mount. All of them were good enough to stack, so here they are. M34 doesn't need 50 minutes of exposure, especially in Athens' bright artificially lit skies, but here's the result.

It's full of galaxies!

Here, filling the upper left part of the picture, is the star cluster NGC 752 in the constellation Andromeda. This is the cluster that fools people when they're trying to sight M33 with the unaided eye. Stack of 5 5-minute exposures, same equipment as above.

But before you look at it, let me call your attention to something. I've rendered the picture rather light for a reason.

The starry background below and to the right of NGC 752 isn't just stars. Quite a few galaxies are visible. I leave it to you to figure out how many; the most prominent ones are near the bottom of the picture. These are roughly 15th- or 16th-magnitude galaxies, all photographed with less than three inches aperture, in town. And every one of them is millions of light-years away and is bigger than the entire sky as you see it with the unaided eye.


Farewell to the ground sloth

This skeleton of a North American ground sloth has adorned the lobby of the Science Library for decades. It was one of Cathy and Sharon's favorite things when they were little. We even have a tape recording of Melody telling the story of the ground sloth so that Cathy and Sharon could hear it any time they wanted.

On November 4, the ground sloth was moved out to the Classic Center. Here you see its original enclosure partly dismantled, the information placard, and the sloth on wheels being moved out.


Three kinds of political foolishness

Time out from astronomy in order to summarize some recent Facebook conversations.

I'm not going to tell you how to vote, but I do want to point out three ways people are making bad political decisions.

First, a lot of people's underlying attitude seems to be, "Life was easier when I didn't know there were people different from myself. I want to go back." This is accompanied by childhood memories (meaning a child's level of knowledge) of an idyllic little town where everybody is just alike. No foreign languages, no other ethnic groups, no international crises.

Once you think about it, expelling everybody different from yourself is not a praiseworthy goal. It's just selfishness, extended to one's own small group.

Besides, if you think America was untroubled and idyllic when you were 8 years old, I invite you to go read a newspaper from that time (whatever time it was).

A second mistake is classifying everything as "liberal" or "conservative" rather than true or false, good or bad, fair or unfair.

The way this game is played, you label yourself "liberal" or "conservative," then you label everything else in the world with those same labels, and you support whatever has the same label as yourself.

This leads to nonsense like "I only read conservative news sources" or even "you can't trust Google, it's 'liberal.'"

The political controversies of 75 years ago, leading to today's labels, do not necessarily contain the solutions to tomorrow's problems. Anyhow, what such a person is looking for is a license to ignore facts, a license to never have to do any thinking.

The third mistake I want to point out is ignoring everything that's too complicated or requires information, simply pretending it's not there, and in general, pretending that the world is simpler than it is.

"ISIS and Islam aren't the same thing? That's too complicated for me. I'll just lump all those A-rabs together and fight 'em all." That's the mindset of a person who can't even distinguish Muslims from Syrian Christians. The real world is too complicated, so we'll just pretend that simple solutions are right.

I think it was H. L. Mencken who said that for every complicated problem, there is a solution that is clear, simple, and wrong.

I also once saw a diplomat quoted as saying that the situation is unclear, and attempts to impose clarity on the situation distort the facts.

Too many people don't mind badly distorting the facts as long as it makes the world seem simpler.

Even worse, I'm increasingly convinced that something terrible has happened to a lot of people's approach to truth and reality — they now think everything is fiction and you can just believe whatever you feel like.

A philosophically minded friend of mine once suggested that such people should step out in front of a bus while trying hard to believe it's not there. That's a bit too gruesome for me, but I see the point.

What happened? Maybe the transformation of news media from reporters of facts to suppliers of emotional entertainment, especially political anger. This has been going on for thirty years. Too many people now go to the news for thrills of anger, not for information and discernment.

Here's why I won't tell you who to vote for. We have two unusually bad major candidates this year, and all I can say is, choose your poison. Bad things are going to happen no matter which one wins, and I want you to be sure, in your own mind, that following your own conscience and the best information you could get, you chose the one that you sincerely thought was less risky. Or, if you considered them indistinguishably bad, you deliberately chose to vote for a third party.

This is not the time for rallying and cheering and being loyal for loyalty's sake. We're hiring a CEO for the government, and there are serious problems with all the applicants.


Pleiades, under a murky sky

I've taken a lot of astrophotos lately, and as usual, I'm going to present them starting with the least spectacular one.

On the evening of October 30, I experimented with autoguiding my AT65EDQ refractor (6.5-cm f/6.5) on my CGEM mount, by mounting my piggyback autoguider (an SBIG STV with a homemade 3.5-cm f/4 objective) on a second dovetail on top of it. This was in town, under a rather bright sky. The Pleiades were in an area where stars were only visible down to about 4th magnitude. But I got something:

Stack of four 5-minute exposures (which is much more exposure than was actually needed) with a Nikon D5300 at ISO 400.

Not a great picture, but you can see the Merope Nebula and some other reflection nebulosity. You can also see that this refractor has no internal reflections. Those are normally the nemesis of anyone photographing the Pleiades. Maybe this year, from a darker site, I'll finally get a really good picture of the Pleiades reaching deep into the nebulosity.

M33 through murk

Here, under the same conditions and with the same equipment as the picture above, is the spiral galaxy M33 in Triangulum. This is a stack of five 5-minute exposures, and it was in a somewhat clearer area of the sky (higher up). It's remarkable how much of the structure of the spiral galaxy I could photograph under such conditions. Note that a bright H II region is visible (a fuzzy bright grayish spot, paired with a nearly matching star to the upper left of center). It is grayish from hydrogen-beta light, which this camera picks up more effectively than hydrogen-alpha.

M15 through murk

This, in turn, is the globular cluster M15 — a type of object that photographs well in spite of city lights. Here it is presented at higher magnification than the pictures above. Same equipment, same evening, stack of three 5-minute exposures. Not bad for a telescope less than three inches in diameter.

If what you are looking for is not here, please look at previous months.