R Coronae Borealis Update

In August of 2007, R Coronae Borealis, or 'R Cor Bor' as we variable star enthusiasts call her, began one of its R CrB-type fading episodes. These fadings are what make R CrB type stars interesting and unique. R CrB is normally a 6th magnitude star, easily observed in binoculars. Occasionally, suddenly and totally unpredictably, the star will fade by as much as eight magnitudes, becoming a faint 14th magnitude star requiring a telescope to observe.

These fading episodes are believed to be caused by the star being dimmed by huge amounts of stellar dust and soot, dredged up from within the star and belched out into its outer atmosphere. Typically, the fading happens rather abrubtly, measured in weeks, and recovery back to maximum light can take several months or a year.

This particular fade has taken on new proportions. Not only has it attained the faintest magnitude in the historical record, it has remained at minimum for longer than ever before also. Some of us are beginning to wonder if the star will ever come back to maximum light again.

Above is the light curve showing the last fifteen years of R CrB activity. Several fading episodes can be seen, but none compares in depth or duration compared to this current fade. The unpredictability and rarity of these type stars makes them favorite targets for variable star observers.

R CrB is heading for solar conjunction. It will be interesting to see what happens when she pops up again in the morning sky. I'll keep you updated.

Simostronomy Podcast on 365 Days of Astronomy

Today's episode of 365 Days of Astronomy features a story from Simostronomy. It's all about a simpler time, and a couple kids dreaming of going to the Moon. The Summer We Flew To The Moon is a fun story about what happens when you don't plan for everything before blast-off.

I'd like to dedicate this one to my mom, since it is her birthday today and she was Mission Control for us and our spacecraft in this story. I always wanted to be an astronaut when I grew up. Thanks, Mom, for never insisting I actually grow up!

Uptick in Orionid Meteors This Year?

According to M. Sato and J. I. Watanabe (2007, PASJ 59, L21) the strong Orionid meteor activity of 2006-2008 may be repeated this year. The increased activity present in 2006-2008 is apparently due to dust trails from comet 1P/Halley, ejected in 1400BC and 11BC.  The orbits of these meteoroids are affected by the 1:5 and 1:8 mean-motion resonances with the planet Jupiter. This resonance effect essentially herds the debris into filaments, and the filament responsible for the increased activity in 2006-08 is expected to lie in Earth's path again around October 18-24 this year. With the moon out of the way this week, meteor watchers should be treated to higher than average counts and bright meteors.

The Loneliest Guy at the Star Party

I don't go to star parties very often anymore. Packing up all the gear, telescope, food, clothes and setting off to remote dark sky sites lost its appeal to me somewhere along the way.

Star parties are part camping trip, part observing opportunity and part social event. Anywhere from a few dozen to hundreds of people come together, pitch their tents or park their campers, set up their telescopes in an open field, swap equipment and stories and share the views through their telescopes through the night.

My wife went to one star party with me a long time ago. She doesn't like to be cold, and when it's clear it's usually cold. She doesn't like to go camping much either. Forget raccoons and porta-potties. Her idea of 'roughing it' is staying in a hotel that doesn't have room service.

I tried my best to make her comfortable. We had these brand new camp lounger chairs, I tucked her into a sleeping bag in the lounger, and covered the sleeping bag with a plastic tarp to keep the dew off her and made a little hood for the back of her head. It was August, and I figured she could at least sit back and watch for Perseid meteors. After a short time, I real bright one exploded overhead and I could hear everyone around us who happened to see it oohing and aahing. Coming from Irene's lounger was the distinct, lady-like, unmistakable sound of snoring. I went back to observing variables with the telescope.

My observing program is mostly cataclysmic variables. 9 out of 10 observations I make are 'less than' observations. In other words, I don't see the star, so it's not in outburst tonight, and I record the faintest comparison star I can see in the eyepiece to set an upper limit on the star's brightness, for example <14.9. Then I move on to the next field to see if anything has popped up since the last time I visited there.

As is the custom at star parties, eventually someone comes around to see what you are looking at and asks for a peek in the eyepiece. So I give them a quick primer on cataclysmic variables, show them the chart so they can identify the field and let them have a look. They stare into the eyepiece for a minute and then say, "where is the variable star?" I tell them it's too faint to see and they walk away somewhat disappointed. Or they'll say, "I can identify the star field, but it's not there?" to which I say, "I know, isn't that cool?" As they walk away they warn the next curious spectators, "Don't go over there. He's looking at nothing!"

It takes a special kind of nutty to do what I do. Like I said, I don't go to star parties very often anymore.

Carnival of Space Quasquicentennial Edition

...that means it is the 125th Carnival of Space; a collection of the best space-related blog posts from the past week.

This week we have entries from:

Next Big Future
Cosmic Ray
Centauri Dreams
Cheap Astronomy
The Chandra Blog
Weirdwarp
AARTScope Blog my new favorite from down under.
Crowlspace
Universe Today
Bad Astronomy
Artsnova
Commercial Space
Telescoper
Simostronomy who?
The Great KSSSM
A Babe in the Universe
Kentucky Space
and from the host, a picture that paints a billion words:  trying to grasp the meaning of one billion thanks to Information is Beautiful.

Messenger Pictures from Mercury

For those astronomy and space enthusiasts that also love LOLCats, here is the largest paw print known to man, from the surface of the planet Mercury.

Photo credit: NASA/Johns Hopkins University Applied Physics Laboratory/Carnegie Institute of Washington

New Slacker Astronomy Episode

This week Doug, Michael and I have a lot fun talking about CCDs and how they work, we answer questions from the reader mail bag about cosmology and the expansion of the universe, and Michael introduces the new Slacker Blogger, Ben Huset. There are a lot of laughs in this one, and we wax a little philosophical here and there. Tune in to the Slacker Astronomy Podcast and join in the fun.

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