19 August 2015

Get Involved: Star Parties in the Bay Area

Get out and see the night sky in the company of other interested people and with amateur astronomers. That is my advice for those who say "I'd love to get out from time to time and look through a telescope at the heavens."

There are plenty of opportunities, starting here in San Francisco with the SFAA (San Francisco Amateur Astronomers). We have two upcoming events, Saturday August 22nd on Mt. Tamalpais and Tuesday August 25th in the Presidio. More information on the SFAA Website.

There are weekly star gazing opportunities every clear Friday and Saturday evening at Chabot Observatory in Oakland.
Chabot's "Nellie" Telescope

The San Mateo County Astronomical Society hosts events in San Carlos twice a month at Crestview Park. Check the site for details.

Outside of the Bay Area you can find local and regional events with the NASA Night Sky Network locator for astronomical events across the USA.

08 August 2015

Perseid Meteor Shower 2015 - August 11-12-13

August means warm nights and the return of one of the year's best meteor showers, the Perseids. This shower peaks on the night of August 12-13 but takes place over a number of days before and after, so start looking up each night and you'll begin to spot more and more. The best nights are August 11, 12 and 13, even more favorable in 2015 due to the lack of moonlight this year.

A Perseid Meteor
To see a meteor shower you don't need to look in any particular direction but up. Meteors enter the Earth's atmosphere and heat up and become visible to us in every direction of the sky, so your chances of seeing more meteors are enhanced by having a big clear horizon and by lying on your back and letting your eyes rest. Some will streak right into your field of view and be brilliant, but many will be off to one side or another, a shimmer in your peripheral vision. You can't rush the process of viewing a meteor shower, so the more time and patience you invest, the more you will see. My experience is that more heads are better than one, so viewing with a friend or two means you will collectively see a lot more and hey, who doesn't like some company on a dark summer's night?

The other factors that are central to an enhanced experience are to get to a dark-sky location if possible, and regardless of whether you find the perfect dark sky location or simply settling into your backyard or rooftop for a view, you want to minimize the lights in your immediate surroundings. So turn off house lights that illuminate your viewing space, and get into the 'shadow of streetlights' if you are in a city, so your eyes have the best chance of adapting to the dark. If you want to see faint objects whizzing across the sky, you should let your eyes have the 10-15 minutes they need to really adjust themselves to your ambient conditions.

Here are two excellent articles about the 2015 Perseid Meteor Shower.

My favorite: Sky & Telescope. And the always-good resource EarthSky.

Image courtesy of EarthSky.

21 July 2015

Southern Summer Skies

Facing South in the Summer
Facing south in the summer reveals a rich region of the night sky featuring the heart of the Milky Way and several excellent zodiac constellations. If you have a clear horizon to the south, the constellation Scorpius dominates the space with a long curving shape that winds around the horizon back to the tip of the tail of the scorpion, a feature called the Cat's Eyes, Shaula and Lesath.

For the next few months, Saturn is lurking next to the head of the scorpion, adding a bright highlight to the pattern. Scorpius and neighboring Sagittarius (to the east) are found directly in the center of the galaxy so there are numerous deep space objects to be found in the vicinity, making it one of the best places to enjoy with binoculars. You can move from spot to spot and never run out of interesting objects to see. This week the gibbous Moon drifts through that region of the sky so the darkness will be somewhat spoiled, but I find it good to get to know constellations when there is moonlight as well as when you have complete darkness. With moonlight you can learn the basic outline of the constellation, and without moonlight the deeper objects will emerge and reveal themselves to the careful viewer.

Image courtesy Sky & Telescope. 

13 July 2015

Pluto and New Horizons

As an amateur astronomer, Pluto is a tantalizing target to find, but one that is quite out of reach for all except the most committed amateur astronomers with the best possible equipment. And even if you locate it in a telescope it will be an extremely faint pinprick of light. So it has never entered my interest until this week. Instead of viewing it from a distance, humanity has finally launched a probe to fly by the planet (ok, dwarf planet) and offer up a close-up during its close passage.

Almost 10 years after launching, New Horizons arrives at Pluto this week. The initial pictures are promising, and I am confident we will be overwhelmed with new data and new discoveries in the days ahead, and in the weeks and months that follow as the vast collection of sensor data is gradually transmitted back to Earth. I loved every major interplanetary mission growing up, watching Pioneer and Voyager vastly expand our knowledge of the Solar System. New Horizons will provide the icing on the interplanetary cake; with our first ever close up of a dwarf planet and a peek into the Kuiper Belt.

Stay tuned to NASA for a busy week of discovery: https://www.nasa.gov/mission_pages/newhorizons/main/index.html 

29 June 2015

The Great Conjunction

The Great Conjunction
When the two brightest celestial objects in the night sky (excepting the Moon) pass next to each other, this is a grand event on an astronomical scale. Jupiter and Venus are doing just that, passing less than a Moon's diameter from each other in a great conjunction, peaking on Tuesday June 30th. A casual spectator should have no trouble seeing the pair, particularly after the glare of sunset subsides (around 9:00 pm or later on the west coast of the USA).

Enjoy this rare and beautiful pairing, made more special by the fact that it's the Queen of Love and the King of the Solar System in close proximity. Who knows what might come of that!

Image courtesy of Sky & Telescope.

27 June 2015

Three Summer Stars in the Milky Way

The arrival of the warm and long days of summer also marks the return of the Summer Triangle and three of the brightest stars in the night sky, Deneb, Altair and Vega. I wax poetically about these sparkling gems when I give a star talk during warm summer nights, with each of the three stars bringing us a unique perspective. All three are in or near the band of the Milky Way, so a close up look at these through binoculars reveals the depths of our home galaxy. This week the Astronomy Picture of the Day (APOD) featured detailed descriptions of these stars and an excellent photograph shown here. Their article says it best.

Three Stars of the Summer Triangle
From APOD: "Rising at the start of a northern summer's night, these three bright stars form the familiar asterism known as the Summer Triangle. Altair, Deneb, and Vega are the alpha stars of their respective constellations, Aquila, Cygnus, and Lyra, nestled near the Milky Way. Close in apparent brightness the three do look similar in these telescopic portraits, but all have their own stellar stories. Their similar appearance hides the fact that the Summer Triangle stars actually span a large range in intrinsic luminosity and distance. A main sequence dwarf star, Altair is some 10 times brighter than the Sun and 17 light-years away, while Vega, also a hydrogen-fusing dwarf, is around 30 times brighter than the Sun and lies 25 light-years away. Supergiant Deneb, at about 54,000 times the solar luminosity, lies some 1,400 light-years distant. Of course, with a whitish blue hue, the stars of the Summer Triangle are all hotter than the Sun."

It's easy to spot the majestic asterism of the Summer Triangle rising out of the east after the late sunsets of June. Take a few minutes to appreciate the three stars that make up this distinctive pattern in the night sky.

Image and text courtesy of NASA and Rogelio Bernal Andreo.

18 June 2015

Approaching a Conjunction

Evening Trio
Each day the planets Venus and Jupiter are drawing closer together in the evening sky, as Jupiter gradually sinks into the western twilight and Venus holds course. The two will have a close encounter (conjunction) on June 30th, but already the two are a striking pair in the evening sky, made more interesting by the waxing crescent Moon this weekend. Look for the trio just after sunset (around 8:45 pm in San Francisco) and watch them become more and more brilliant as the sunset sky turns to dusk and eventually to darkness.

Image courtesy of Sky & Telescope.

31 May 2015

Jupiter and Venus Closing In

Jupiter and Venus
The two brightest objects in the night sky (after the Moon) are closing in for a very close encounter in June. Each evening you can watch the gradual change as Jupiter descends in the west toward Venus. As both planets are on the same line of travel across the sky (the Ecliptic), they pass near each other typically once per year. This is going to happen in 2015 in late June. For now, check out the daily movement in the west after sunset. I'll write more about the close encounter in the month of June.

Image courtesy Sky & Telescope.