By Dave Fuller on 1/26/2015 7:24 PM
Algol is an interesting star name; it comes from the Arabic "ra's al-ghūl" that literally means "head of the ogre, or ghoul." While the evidence of our ancient ancestors having seen the variable nature of this star is lacking, it would behighly coincidental then that this star is also where Perseus is said to be holding the decapitated head of the Gorgon Medusa. Algol magnitude dip and brightenShe was the snake-headed beast that could turn living creatures to stone that were unfortunate enough to gaze upon her face.

And the star is a "winking" one; while the other stars in the heavens would have largely appeared of constant brightness, Algol may have been known to dip in brightness. Today, we know that period is 2 days, 20 hours and 49 minutes. 

Because of this, the star is not always...
By Dave Fuller on 1/22/2015 9:09 PM
Those of us on Earth won't get a chance to see a triple moon transit across the face of Jupiter for another 17 years... so if it's cloudy, well, you may just have to settle for this animated gif:

Jupiter triple transit animated gifLasting a mere 25 minutes - really a few minutes less than that by the time each Moon is fully into view or before it leaves view - there is not a lot of time to see it. But, there will be plenty of time to view and share this event. 

What will you see? In the graphic above, Io is on the left, Callisto is center, and Europa's shadow on the right. If you look several hours earlier in the evening, you can see Io first on the right side of the shadow of Callisto, then racing to catch up, and actually passing it on the left side. 

So if clouds thwart your efforts later, or you just plain get tired, you can still at least see a double transit occurring. While not rare, they don't happen all the time. 

...
By Dave Fuller on 1/19/2015 4:11 PM
Mercury has just about had enough of us Earthlings gazing at it for the last couple of weeks during this greatest eastern elongation in the western sky (Mercury's furthest highest point towards the east above the horizon in the west after sunset is called the greatest eastern elongation.) But while the rocky innermost world was sharing the stage with brilliant Venus, with Mars hovering over the two, the Moon was finishing it's rounds on the morning side of our sky.

Mercury, Venus, Earth, Mars and Moon on Jan 21

Now it returns to the evening, and YOU can capture this event with either your naked eye (look carefully!), binoculars, or with a camera (use a tripod).

On January 21st, the Moon will be about "three finger width's at arm's length" or 5 degrees or so away from Venus, and a bit less than that from Mercury. These graphics display the Moon's...
By Dave Fuller on 1/14/2015 9:12 PM
Comet Lovejoy remains quite bright and easy to find with binoculars of 7x35 or larger under most skies. The comet does not dim appreciably, but over the next 7 days or so, it is very near to the easily found Pleiades. It isn't quite within a single binoculars field of view (typically 7 degrees or so), but it is close enough that making the "hop" over to it should not be too difficult.

Check out the day by day descriptions of how to find the comet at the bottom of this post. First, here's the large, wide field view so you can get oriented (look mostly south, around 8 pm or so for most people). 

Comet Lovejoy wide field star chartThe Pleiades make the better "jump off" point for the next 7 days or so. Note that just like in the prior post,...
By Dave Fuller on 1/12/2015 4:13 PM
Marveling at Mercury Have you ever seen Mercury? Not the metal found in thermometers; the actual planet. It is surprisingly bright, but many people don't know when or where to look. This month offers the perfect time to try and spot this elusive solar system speedster.

Mercury is the innermost planet of the solar system. As such, we refer to both it and Venus as "inferior" planets - that is to say, they orbit the Sun inside of Earth's orbit (the other planets are called "superior" planets). Because of this location in our solar system, these planets never cross the sky, and they never reach opposition with Earth. Rather, the best time to see them is when they obtain the position of "greatest elongation." Yet Mercury is somewhat elusive. It orbits the Sun in just 88 days - less than a full season on Earth. Despite shining at over magnitude 1 much of the time when it is brightest, it is forever stuck in the twilight glow of the Sun. One never sees it under a truly dark sky, so observers really HAVE to be...
By Dave Fuller on 1/10/2015 6:14 PM
Comet Lovejoy is a bright comet by most standards. In a way, it is fortunate that it was not hyped by news media as a "BRIGHT, NAKED EYE COMET!" because unless it's Hale-Bopp bright? Then most people will be disappointed. So Comet Lovejoy C2014 Q2 actually is nice in the respect that it kept expectations low, then exceeded them when it brightened up nicely over the past couple of weeks. Now that the Moon is mostly out of the way, this is a perfect time to see the comet, despite the fact that it is just past it's closest point to Earth. It is still bright, it isn't getting appreciably farther from Earth over the next couple of weeks, and the Moon is now nicely out of the way for most viewing opportunities.

That makes this ideal. How to find it? Below are both a wide-field, and a detailed chart for January 11 through 15. These are listed as Universal time, so for European viewers, it's about in that spot at midnight. For North American viewers, it is in that spot early in the evening (for most, around 7...

The Nightlight

This blog includes what to see in the night and daytime skies, thoughts on telescopes, binoculars, and other astronomy observing accessories and equipment, plus my own occasional notes on objects I've seen and observed. Oh, and the random theater or other "my take on life" post. In other words, there is always something interesting. Check it out.