Tag Archives: Eta Aquariids

About The Perseid Meteor Shower (“Perseids” For Short)

Greetings fellow astrophiles!

This article has been posted in preparation for our Perseid Session and International Starry Night event at Baltimore Woods this coming Monday, August 12th (with the 13th as the weather-alternate). We might even get a view or two of the Perseids at our Thursday, August 8th Beaver Lake Nature Center lecture!

The Perseid Meteor Shower is an almost perfect combination of location and timing for amateur astronomers and the general public, as the Earth grazes a rich debris field from the tail of Comet Swift-Tuttle during the peak of the Northern Summer. We’ll cover the details of this confluence below so you know what makes the Perseids the most anticipated (and observed) meteor shower of the year.

One Thousand And Thirty Words (And Two Numbers)

Comedian: “Ask me what the key to comedy is.”
Assistant: “What’s the -”
Comedian: “Timing!”

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The image above shows all of the important pieces of the Perseid puzzle. We find the Earth in its orbit around the Sun as it approaches a mid-August position (the 10th to the 14th, although one may see meteors at the fringe of Perseid territory several nights before and after) that finds Earth (and us) scraping against the edge of a debris field produced by Comet Swift-Tuttle on its 133-year orbit around the Sun. Last seen in our vicinity in 1995, observers will have to wait until the 2120’s for another good view of its flaring core. Fortunately, it leaves enough tiny pieces of itself as it draws close to the Sun to provide us with a brilliant reminder of its existence every mid-August.

Unlike Halley’s Comet, which passes close to Earth’s orbit on its way toward (producing the Eta Aquariid Meteor Shower in early May) and away from (producing the Orionid Meteor Shower in late October) the Sun, Comet Swift-Tuttle’s eccentric orbit finds it passing close to Earth only at one point, like a snapshot capturing a hula-hoop (Swift-Tuttle’s orbit) as it touches the belt buckle (Earth) of a gyrating dancer whose waist is Earth’s orbit in circumfrence.

What’s In A Name?

We refer to this meteor shower as the “Perseids” because the meteors associated with Swift-Tuttle appear to streak across the sky from a point (known as a “radiant“) originating in the direction of the mythical constellation Perseus. The shower itself has nothing to do with the stars of the constellation Perseus, only the part of the sky that Perseus occupies on the late nights and early mornings in mid-August. One might even consider Perseus the beneficiary of this shower, as the constellation has taken on a new-found importance to astronomers over the last several millennia as the marker for this shower in the August skies.

It’s All Relative

Anyone caught driving late at night during a snow storm knows the sensation of making the Millenium Falcon’s “jump to lightspeed” as the snowflakes appear to shoot towards, then past or onto, your windshield. To the driver cruising at 65 mph on a highway, the snowflakes appear to have no motion but the one directly towards the windshield. If you were standing on a snowflake, you’d notice the very slow decent to the Earth’s surface, the rapidly oncoming car headlights, then the swift rush across the windshield as the aerodynamics of the windshield combined with the high speed of the car.

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This same state of “relative observation” occurs during all meteor showers as the Earth revolves around the Sun. The meteors, themselves mostly no larger than grains of sand, are not moving rapidly towards the Earth’s atmosphere. They lie scattered about the path of Comet Swift-Tuttle, a result of the comet heating enough as it approaches the Sun to lose small pieces of its surface. If Swift-Tuttle were a massive gravel delivery truck (to continue the driving analogy), these small grains would be the random pieces of rock that fall to the ground as the truck bumps over uneven pieces of highway.

Clash Of The Tinys

It is the Earth, revolving around the Sun at a dizzying 110,000 km/hour (that’s 30 km/second!), that powers the meteor shower we see on the ground. As the Earth rushes through the debris field of Comet Swift-Tuttle, these tiny grains of comet come into contact with our atmosphere at speeds so great that they ignite the air around them, causing brilliant streaks of light as the tiny grains are incinerated.

The number of meteors one can observe over a Perseid session is determined by (1) your looking at the right place at the right time (no long blinks!) and (2) the density of tiny Swift-Tuttle-ettes in the comet’s orbit as Earth passes through it. There are some meteor showers where one is lucky to see a few per hour. Because the Earth passes through a generally rich part of Swift-Tuttle’s orbit, two or three per minute may not be uncommon for a “usual” Perseid session. Those outside for the 1972 Perseid Meteor Shower were treated to what many believe to be the best meteor shower in recorded history (and those outside for the 1998 Leonid Meteor Shower (a close second by all metrics) know what it’s like to see thousands per hour raining down on dark skies).

Finding Perseus

The Perseids appear to radiate from the constellation Perseus. For your best chance of seeing Perseid meteors, it is not your eyes that should be transfixed on the heart of Perseus. Instead, you should anchor the bottoms of your toes towards Perseus, then find a comfortable piece of ground (or reclining chair) that gives you a clear view of the sky right above you. Perseid meteors will then, with a thick patch of debris field and a bit of patience, appear to blaze across the night sky from your toes (Northeast) past your head (to the Southwest).

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Perseus will appear to rise above the Northeast horizon after 9:00 p.m. Directly above the stars of Perseus resides Cassiopeia – a giant and prominent “W” in the night sky that, for many hours after sunset, will appear as a West-facing throne for this ancient Ethiopian queen. Those familiar with the many tricks amateur astronomers use to learn the Night Sky will simply find Polaris, perhaps using the two end stars of the bowl of the Big Dipper and an imaginary line along these stars in the direction of the bowl’s open face to pick out the dim North Star. Polaris does not shine with the brightness one might have imagined for the second most important star in the sky (after our own Sun), but it is in a piece of sky that contains few brighter stars, making it the most obvious member of a very modest piece of northern sky.

If you’re still too new to constellation hunting, the solution is simple! Grab a compass (or a compass app in your smart phone) and find Northeast the new-fashioned way. With luck, the Perseids will race to the Southwest at a rate of a few per minute, increasing in count, then decreasing, from around 10:00 p.m. to 4:00 a.m. local time. With the good fortunes of all the Olympian Gods, we’ll all be treated to many, many more.

Additional Information

The Perseid Meteor Shower

en.wikipedia.org/wiki/Perseids
earthsky.org/astronomy-essentials/everything-you-need-to-know-perseid-meteor-shower
solarsystem.nasa.gov/planets/perseids.cfm

Comet Swift-Tuttle

en.wikipedia.org/wiki/Comet_Swift%E2%80%93Tuttle
ssd.jpl.nasa.gov/sbdb.cgi?sstr=109P

Meteors And Meteor Showers

en.wikipedia.org/wiki/Meteor_shower
leonid.arc.nasa.gov/meteor.html

CNYO Observing Log: Baltimore Woods, 5 April 2013

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Bob Piekiel’s monthly session at Baltimore Woods featured crystal clear skies, increasingly cold conditions (a recurring theme this year for all of the previous sessions), and one large scope.

This Baltimore Woods session was the last scheduled event before our Winter constellations all-but disappear from our nighttime skies. To this pressing deadline was added the last reasonable observation of Comet panSTARRS (C/2011 L4) from the same location, as the return of the foliage through May will all-but obscure the parts of the North/NorthWest horizon that are not already obscured by naked branches. The event itself was scheduled from 7:30 to 9:30 p.m., ending an hour before any first observation of Saturn for the evening. The ever-dropping temperature that evening found us ending the session promptly to the sound of running (with heat on full-blast) cars and depleted propane.

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Bob Piekiel and the author post-assembly.

With a confirmed heavy lifter attending (me), Bob opted to bring out a 16” Meade SCT on a homemade tripod that is (minus the scope) transported in the open – the whole considerable contraption hitches to the back of the car. After a bit of heavy lifting and careful coordination to get the scope up to the mount, the completed assembly was ready for the first signs of bright stars (in this case, Sirius and Capella) to perform the alignment. The time waiting for bright star arrivals was passed with the help of a pair of Zhumell 25×100’s that saw (1) clear views of Jupiter and all four of its largest moons and (2) Sirius in Canis Major to the West.

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Bob Piekiel putting the finishing touches on a 16″ Meade SCT.

The height of the tripod combined with the extra 8” of wheels on the mount’s base meant that a step ladder was required for nearly all viewing throughout the night. With the 16” SCT aligned, the first official view (pre-dark sky) was of Jupiter, which was bright and clear in Bob’s 40 mm Meade eyepiece. The second object was Trapezium in the Orion Nebula (M42), which was also crisp and clear despite our observing it only minutes after sunset.

The third object observed combined low brightness with near-horizon position just past dusk. Bob managed to find Comet panSTARRS almost due North of the Andromeda Galaxy just as it was about to hit the bare tree line. The view was excellent for several minutes as everyone had a few looks at this increasingly difficult-to-observe object (comet’s center was reasonably well defined, but this was a 16” scope with a 40 mm eyepiece). And, it should be noted, the object database in Bob’s GOTO computer is not only older than the discovery of Comet pan-STARRS, but also quite a bit older (decade? maybe two?) than the Panoramic Survey Telescope and Rapid Response System (Pan-STARRS) that originally identified the comet. So, extra kudos to Bob for the timely find!

The cold set in quickly after these first three objects, meaning the last four objects for the evening were approached with haste. In a return to the objects of his last session, Bob treated attendees to excellent dark views of M65 and M66 in Leo, M108 (a faint edge-on galaxy near the Owl Nebula in Ursa Major that was as bright in the 16” as it was with Bob’s 11” scope + image enhancer), and the Owl Nebula (M97). Bob and I saw this final object as a confirmation that it hadn’t flown the coop during our last session, where the image enhancer failed to produce any particular view of this object (see the last session notes for details).

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New supernova in M65. Photo by Felipe Pena.

NOTE: I wish I had known earlier that a new supernova was discovered in M65! As a general point of reference, those looking for the most complete and up-to-date information about supernovas are directed to David Bishop’s excellent Bright Supernova database and log at www.rochesterastronomy.org/supernova.html. Details and many, many images of the new supernova in M65 can be found at: www.rochesterastronomy.org/sn2013/sn2013am.html

The totality of views through the Zhumell 25×100’s were limited to Jupiter (as a sampling for the attendees before the 16″ was properly GOTO’ed), Sirius (just to the left of Orion and the brightest star in our Night Sky), the Double Cluster in Perseus (bright and densely packed), and the Pleiades (M45), the object for which I assume 25×100’s were originally designed to observe (near-perfect fit of the whole cluster in the field of view).

A few street lights and distant clouds to the East reflecting Syracuse back down provided all the illumination that the stars didn’t as we began to pack up the gear at 9:30 p.m.

And did the 3rd Quarter Moon affect the viewing? For those observing at “reasonable” hours, it is the case that the 3rd Quarter Moon doesn’t rise until midnight, meaning the week before a Full Moon, the week of a Full Moon, the few days before a 1st Quarter are excellent for getting outside to observe deep sky objects at “reasonable” hours (reasonable being relative, of course).

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Not a lunar landing scene. Mid-way through the 9:30 pack-up.

Next session is scheduled for May 4 (Saturday) – 5 (Sunday), 8-10 p.m. and will feature Jupiter, Saturn, and hopefully a few shooting stars from the Eta Aquariids meteor shower. For details and registration, see the details on this CNYO page.

Bob Piekiel Hosts Observing Sessions At Baltimore Woods – 2013 Observing Schedule

I’m pleased to have obtained the official schedule for Bob Piekiel’s Baltimore Woods programs for the 2013 observing season and have added them to the CNYO Calendar. For those who have not had the pleasure of hearing one of his lectures, attending one of his observing sessions, or reading one of his many books on scope optics (or loading the CD containing the massive Celestron: The Early Years), Bob Piekiel is not only an excellent guide but likely the most knowledgeable equipment and operation guru in Central New York. I’ve (Damian) attended two of the Baltimore Woods sessions already and plan to be present for as many of the scheduled events below as possible.

Note:

The Baltimore Woods events calendar is updated monthly. As such, I’ve no direct links to the sessions below. Therefore, as the event date nears, see the official Calendar Page for more information and any updates on the event.

Also…

* Registration for these events are required. Low registration may cause programs to be canceled.
* $5 for members, $15/family; $8 for nonmembers, $25/family.
* To Register By Email: info@baltimorewoods.org
* To Register By Phone: (315) 673-1350

* Friday, February 8th (Backup – Saturday 9th), 7-9 p.m.

(Available link HERE) Another fabulous look at the bright winter skies and all the glories surrounding the constellation of Orion, the Hunter. The king of the planets, Jupiter, visible as well, as will the ice giant Uranus.

* March 15 (Friday) – 16 (Saturday), 7-9 p.m.

Comet Panstarrs should be visible in the west shortly after sunset. Its brightness is a guess at this time, but it could be quite a stunning sight. Jupiter will be visible, along with the winter skies and some of the brightest examples of nebulae and star clusters.

* April 5 (Friday) – 6 (Saturday), 7:30-9:30 p.m.

Comet Panstarrs will be visible in the northwest after sunset, right next to the Andromeda galaxy! While we can’t be certain of its brightness, it may be a stunning sight. Jupiter will be visible all evening, and Saturn will be rising in the east.

* May 4 (Saturday) – 5 (Sunday), 8-10 p.m.

Eta Aquariids meteor shower, Saturn and Jupiter visible all evening, and hello to spring skies.

* June 14 (Friday) – 15 (Saturday), 9-11 p.m.

Because it gets dark very late in June, it makes sense to do a 1st-quarter moon program, as we don’t need dark skies to get great views of the moon. Saturn will also be visible, and the start of summer skies.

* July 12 (Friday) – 13 (Saturday), 9-11 p.m.

The summer milky way at its finest. During the summer, we look directly into the core of our own milky way galaxy, giving great views of many beautiful star clusters and nebulae. The planet Saturn will be visible as well.

* August 12 (Monday) – 13 (Tuesday), 9-11 p.m.

It’s the annual Perseid Meteor Shower, one of the year’s finest, along with great views of the summer Milky Way, the ringed planet Saturn, and also Uranus and Neptune. Bring a lawn chair or blanket to lie back and watch for meteors when you’re not at a telescope.

* August 24 (Saturday) – 25 (Sunday), 1 p.m.

Solar observing session, with safe views of solar detail using specially-filtered telescopes.

* September 27 (Friday) – 28 (Saturday), 7-9 p.m.

Uranus will be in best viewing position all night long, plus Venus and Saturn in the west just after sunset. We will say goodbye to the Summer Skies.

* October 11 (Friday) – 12 (Saturday), 6:30-9 p.m.

Oct. 12 is National Astronomy Day, Part 2, but let’s do our usual Friday the 11th with Saturday being the backup. This will be our best chance to see Mercury for the remainder of the year, along with a crescent Moon and Venus as well, plus hello to Fall skies. We will need to start early to glimpse Mercury.

* November 4 (Monday) – 5 (Tuesday), 7-9 p.m.

Nov. 4-5 for the Taurid Meteor shower, plus hello to Winter skies. The Taurids are a modest shower, but in contrast, the Leonids, which occur on the 17th, are going to be completely washed out this year by a full Moon.

* December 13 (Friday) – 14 (Saturday), 7-9 p.m.

The Geminid Meteor Shower – the year’s best (it sure was fantastic last year!) and Winter skies, with the brightest examples of clusters and nebulae, such as the great Orion Nebulae.