Remembering Comet Holmes

Twelve years ago today, Comet Holmes (17P) brightened from magnitude 16.5 to 2.6, forming a right triangle with Mirfak (α Persei) and δ Persei, opposite to Algol. Here is what I wrote in The Sky This Week at that time.

TSTW 10/25/07

Comet Holmes Bursts on the Scene!

Who ever said astronomy isn’t exciting? Sure, much of what we observe in the cosmos seems predictable and unchanging—but then something unexpected happens and we are scrambling to get a front-row seat and our lives are thrown into an exhilarating tizzy for a few hours or days. Whether it be an unexpected auroral display, a meteor fireball, a nova, supernova, or comet, the result is the same: it is exciting to be an astronomer, to be attuned to a universe that existed long before we were born and that will be here long after we are gone. That, to me, is comforting.

Very early Wednesday, October 24, a 16th-magnitude short-period comet presently in Perseus by the name of Holmes brightened about 14 magnitudes from 16.5 to 2.6 in little more than 12 hours: a brightness increase of 363,000 times! While such a cometary outburst was unexpected, it is not unprecedented. From time to time, solar heating (greatest when a comet is near perihelion) must cause pressure to build up inside a comet as subsurface ices volatilize. Eventually, the pressure builds up until it explodes through the surface of the comet, spewing gas and dust into space and exposing fresh material to solar radiation. Sometimes, this process is so violent that the comet breaks into multiple fragments.

Comet Holmes (17P) is one of the so-called “short period” comets, meaning it orbits the Sun in less than 200 years or has been observed at more than one perihelion passage. Comet Holmes orbits the Sun every 6.9 years, ranging from just inside the main part of the asteroid belt (2.1 AU) to the orbit of Jupiter (5.2 AU). No doubt Comet Holmes’ original orbit has been substantially altered by the gravitational influence of Jupiter. Comet Holmes is presently 2.5 AU from the Sun (230 million miles) and 1.6 AU from the Earth (150 million miles), having just passed perihelion on May 4, 2007.

Comet Holmes was discovered during its last outburst, which occurred on November 6, 1892 by English amateur astronomer Edwin Holmes (1839-1919). It was observed again in 1906, but was then lost until being recovered in 1964. It has since been observed near perihelion at every return.

The recent outburst of Comet Holmes may be one for the record books. I am not aware of any other comet outburst being recorded where the comet brightened by as much as 14 magnitudes in less than a day! Fortunately, the first two nights after the outburst the sky was beautifully clear here. The first night, October 24, Comet Holmes looked like a star to the unaided eye. In binoculars, it looked like a tiny yellow or orange planetary nebula, only slightly bigger than a star, and of uniform brightness. The following night, October 25, it still looked like a star to the unaided eye, but in binoculars it was larger than the previous night. The total brightness had not diminished. In the telescope, the comet was truly spectacular, made all the more amazing considering how the comet was only 43° away from the closest full moon of the year! The round coma contained a bright off-center fan-shaped wedge with a brilliant tiny pointlike nucleus. There was definitely evidence of concentric, spiraling shells of material opening outward from the center of the coma to the outermost parts of the coma.

You have just got to get out to see this comet! And as often as possible! Here is an ephemeris for Dodgeville for the coming week.

TSTW 11/1/07

Comet Holmes (17P)

Comet Holmes slowly moves towards Mirfak this week, an impressive binocular and telescopic object in Perseus. It is easily visible to the unaided eye, too, as a small fuzzball on the Capella-side of Perseus.

Sunlight and solar wind particles are hitting the comet on the north-northeast side, and photographs show the comet is sharp edged there. The opposite, south-southwest side is ragged, with ionized gas streamers spreading out in that direction in long-exposure photographs.

Whatever tail the comet has is pretty much hidden behind it, as our viewing angle (known as the phase angle) diminishes from 15° to 13° this week. The phase angle is the Sun – Comet – Earth angle. A phase angle of 0° would mean we are looking directly down the tail (least favorable, maximum foreshortening). A phase angle of 90° would mean we are looking perpendicular to the tail (most favorable, no foreshortening).

Prime time for observing the comet is pretty much all night, with the comet transiting the celestial meridian at 2:05 a.m. CDT at the beginning of the week, and at 12:30 a.m. CST by the end of the week. Look at it every clear night, because surprising changes can and do occur. Don’t miss it! It may be a while until something like this happens again. The last time Comet Holmes went into a major outburst was 115 years ago!

Streetlighting Concerns

I submitted the following letter to the editor to the Dodgeville Chronicle this evening:

Dear Editor:

Have you noticed the gradual transformation of our streetlights in Dodgeville, Mineral Point, and other communities in SW Wisconsin?  The light source in our streetlights is changing.  High Pressure Sodium (HPS), which has been in use for decades and produces a orangish-white light, is being replaced by light emitting diodes (LEDs), producing a whiter light.

What’s not to like?  LED’s many advantages include: efficiency, longevity, instant-on and instant-off, and dimmability, to name a few.  But Alliant Energy is installing new streetlights that produce white light that is too blue, and the illumination levels are about 2.6 times as bright as the high pressure sodium streetlights they are replacing.

Lighting specialists use a term called “correlated color temperature” or CCT (in Kelvin) that allows us to compare the relative “warmness” (redder) or “coolness” (bluer) of  various light sources.   The illumination provided by candlelight has a CCT around 1500 K, HPS around 2000 K, an incandescent light bulb around 2800 K, sunrise/sunset around 3200 K, moonlight around 4700 K, and sunny noon daylight around 5500 K.  The higher the color temperature, the bluer the light.

Higher color temperature illumination is acceptable in workplace environments during the daylight hours, but lower color temperature lighting should be used during the evening and at night.  Blue-rich light at night interferes with our circadian rhythm by suppressing melatonin production, thus reducing sleep quality, and several medical studies have shown that blue light at night increases the risk of developing cancer, most notably breast cancer.  Even low levels of blue-rich light at night can cause harm.  While it is true that something as natural as moonlight is quite blue (4700K), even the light of a full moon provides an illumination level of just 0.01 foot-candle, far dimmer than street lighting, parking lot lighting, and indoor lighting we use at night.

LED streetlights are available in 2700K, 3000K, 4000K, and 5000K.  I believe that Alliant is installing 4000K streetlights in our area—I certainly hope they are not installing any 5000K.  What they should be installing is 2700K or 3000K.  These warmer color temperature lights are no more expensive than their blue-white counterparts, and the slightly higher efficiency of the blue-white LEDs is entirely nullified by over-illumination.

Even considering a modest lowering of light level with age (lumen and dirt depreciation), these new LED streetlights are considerably brighter than the HPS lights they are replacing.  Just take a look around town.  What is the justification for higher light levels in our residential areas, and when was there an opportunity for public input?  In comparison to older streetlights, the new LED streetlights direct more of their light toward the ground and less sideways or directly up into the night sky, and that is a good thing.  But now the illumination level is too high and needs to be reduced a little.

If you share my concerns about blue-rich lighting and illumination levels that are often higher than they need to be, I encourage you to contact me at oesper at mac dot com.  I operated an outdoor lighting sales & consulting business out of my home (Outdoor Lighting Associates, Inc.) from 1994-2005, and wrote the first draft of the Ames, Iowa Outdoor Lighting Code which was unanimously adopted by the city council in 1999, so I am eager to work with others in the Dodgeville area who are also interested in environmentally-friendly outdoor lighting.

David Oesper

Orion’s Throwing Stones!

Monday evening, October 21st, and Tuesday morning, October 22nd, will be the best time to watch the Orionid meteor shower, one of the year’s best meteor showers.

Up to two dozen meteors per hour might be seen between the hours of 3:00 a.m. and 5:00 a.m. or so— provided you can keep the 40%-lit waning crescent moon out of your field of view.

When to Watch:

10:16 p.m. Monday, October 21 through 12:19 a.m. Tuesday, October 22 (radiant rise in the ENE to moonrise)*

12:19 a.m. through 5:47 a.m. Tuesday, October 22 (moonlight will interfere; radiant will be highest in the sky at 5:18 a.m., and morning twilight begins at 5:47 a.m.)

Where to Be: In a rural area with no terrestrial lights visible that are brighter than the brightest star. Preferably no light domes (uncivil twilight) of cities or towns should be visible in the direction you will be looking.

What to Do: Dress for a temperature 20° F cooler than the actual air temperature. Bring a lawn chair and a warm sleeping bag or blankets. Try blocking the Moon with a building, hill, or trees— or use a strategically-placed black umbrella.

Where to Look: Generally look towards the radiant which is between Betelgeuse and the “feet” of Gemini.

What You’ll See: Fast meteors, many leaving persistent trains.

Meteor showers occur each year when the Earth in her orbit intersects the debris trail of a comet, and the comet that causes the Orionids is very famous, indeed. Halley’s Comet!

* Times listed are for Dodgeville, Wisconsin

Cell Phone Fiasco

I am one of the holdouts who really has no interest in carrying around a smartphone everywhere I go. I spend most of my day in front of a computer screen, get far too many emails to keep up with, and have even less time for social media. I treasure the precious little time I have to be “unplugged” and do not want my treasured (and increasingly rare) face-to-face interactions to be interrupted by technology—nor do I want to be distracted by it.

To me, a screen is to be viewed, not touched. I much prefer a physical keyboard, and web browsing on a large screen. I hate all the pop-up ads on a smartphone browser, and all the places you go to accidentally while swiping to scroll.

For several years, I have had a great basic cellular phone with a slide-out keyboard, the LG Cosmos 3.

The LG Cosmos 3 – A Basic Phone with Slide-Out Keyboard

I do more texting than phoning, so this phone works great for that, and it is smaller than a smartphone. Recently, the charging port on my LG Cosmos 3 gave out and I could no longer charge the phone.

LG Cosmos 3 Charging Port
USB to Micro USB Charging Cable

There has got to be a better way to charge a phone like this that avoids all the wear and tear plugging and unplugging the micro USB plug into the phone. I first took the phone to a couple of phone repair shops in Madison, but they both said they could not fix or replace the port. I then took the phone to Verizon. Here’s what I found out:

  1. Verizon cannot fix the LG Cosmos 3 charging port.
  2. The LG Cosmos 3 is no longer available.
  3. The LG Cosmos 3 is a 3G device, and Verizon will be shutting that network down on 12/31/19 so even if the phone could be fixed, it won’t work after that date, nor will any other 3G device.
  4. No cell phone is currently available with a slide-out keyboard.

What?! No basic phone with a slide-out keyboard for texting? After spending several hours researching other cellular phone service providers and manufacturers, I discovered that no 4G/LTE phone with a slide-out keyboard exists. My only basic phone option was to go back to a flip phone where texting would require the multi-tap entry system on 12 keys. Slow and tedious, like it was on earlier generations of cell phones. This is progress?

After a second visit to the Verizon store, I decided to purchase the LG Exalt LTE flip phone. My very positive experience using the LG Cosmos 3 gave me a good reason to stick with LG. Though I like the LG Exalt LTE phone, texting is tedious. I really hope that LG will release an LTE version of the Cosmos 3. LG Cosmos 4, perhaps?

If you feel as I do that cell phone manufacturers like LG should once again offer a basic phone with a physical QWERTY keyboard, please sign this petition on