2011 Sky Calendar for Arizona with HAC event dates

2011 Sky Calendar for Arizona

You can find the November update and future versions of Doug Snyder's Sky Calendar Blog at this website:

http://skycalendar.blackskies.org

An update for the annual Draconid meteor shower during the morning hours of Saturday, October 8; to be on the 'safe' side, I would suggest viewing, if possible, on the early morning hours of both October 7 (Friday) AND October 9 (Sunday). The reasons for this is due to the locations and times in which the peak is anticipated. On Saturday, the Moon, at almost 90% phase, will be setting somewhat after 3 AM, and astronomical twilight will begin right around 5 AM. The peak of the shower is, unfortunately, expected to occur over regions of Europe and Africa, and at rates approaching 1,000 meteors per hour. It is interesting to note that rates exceeding 10,000 per hour were seen in 1933 and 1946. This year, the western United States are not expected to be favored during those best meteor observing hours before dawn. But let's still be out observing on those suggested dates, just in case! What else do you have to do during those times? The parent comet for this meteor shower is Comet Giacobini-Zinner, a short period comet also designated 21P, and which has an orbital period of about 6.6 years. It was discovered in December of 1900, and the last perihelion date was in July of 2005.

Another major meteor shower that occurs in October is of course the Orionids! This year the peak is expected on the late evening of Friday, October 21 and continue into the morning hours of Saturday, October 22; although there is a 45% waning Moon, it will not rise until shortly before 1 AM, but after that, it will present somewhat of an obstruction to viewing. The radiant for the shower is near the 'elbow' of Orion, and the parent comet of this shower is Halley's Comet.

Observe the showers in October, and shoot some photos of them! Don't be shy to show them on the hac-list or elsewhere online- just let us know about them! I plan on having my DSLR on a tripod, and having a slew of exposures at least of 30 seconds each. For more meteor photography tips, visit this web page:

On October 28, at 7 PM Arizona Time, the planet Jupiter reaches opposition. The major four satellites of Jupiter are Io, Europa, Ganymede, and Callisto.

Have a great observing October, and in the meantime, don't hesitate to contact me with your questions or comments. My email is starhaven AT palominas DOT com

--Doug Snyder (C/2002 E2)

Hi Stargazers: In Arizona, and of course elsewhere, this month of September, 2011 holds promise that it will be a very active, productive, educational, and enjoyable period of astronomical events! Even more so if you allow yourself to get involved and really, really participate in some of these events, whether doing it 'solo' or with others- we are given the night, every night, not just to sleep, but to explore, discover, and enjoy every little bit of this amazing Universe. So let's do it! Please take note that times used in this update are shown in Arizona's Mountain Standard Time and not Universal Time or daylight savings time except as noted. Anytime is a good time to comment on this blog, and I look forward to getting your reports, gripes and any comments- email me at starhaven AT palominas DOT com

On this month's Sky Calendar, the agenda is full from the first of the month to the end of the month. Of course, on the 23rd (Friday), is the Equinox and that occurs at 2:06 AM our Arizona time on that day. We all know that this 'fall' equinox time is when our Sun, traveling along the 'ecliptic', arrives at the point where it crosses the equator into the celestial southern hemisphere.

There is currently a pretty good comet in our binocular and telescopic viewing portals. This is comet C/2009 P1 (Garradd). For the early part of September, you can locate it near or in the constellation of Vulpecula and in fact, quite near the asterism known as 'The Coathanger'. The comet is at around magnitude 7. Later in the month, it will appear in Sagitta, and then in the southeastern portion of Hercules. Wow, this is so cool! Again, reports of your observations are welcome, and of course, any images that you've captured as well. We really need a bright naked-eye comet!

Possibly the best star party event for the month, and I am positive there are quite a few taking place throughout the month, is the STAR NIGHT at Kartchner Caverns on Saturday, September 24. Yes, the very same Arizona State Park near Benson and Sierra Vista in the southern end of the state, very accessible from State Highway 90. This event is highly recommended if you can attend, and bring the family! If you can also bring along a telescope, that's icing on the cake!

Let's review some of the many other events that are shown for this month's sky calendar (the 2011 version is downloadable from www.hacastronomy.com ).

For September 1, we enjoy dark skies for a meteor shower! It seems that this shower, the 'alpha' Aurigid Meteors will arrive at its peak at about 4:30 AM on 9/1, and although the dark sky timing is favorable, we are not sure what level of activity to expect! In some years past, there have been moderate outbursts with quite bright, and fast, members, and the radian appears to be near the bright star Capella, of course found in the constellation Auriga. The parent comet for this shower is a long period comet named C/1911 N1 (Comet Kiess). Let's have a 'go' at this shower and don't be hesitant to report what you see, even if just a starry night in Auriga!

Progressing into the morning of September 2nd, we have the planet Mercury reaching its greatest elongation West from the Sun (18 degrees), so this will be a fine showing of Mercury in the predawn morning skies. Be up and out early to catch this one! For about a week or more, you can also follow Mercury playing 'tag' with the number one star in Leo, Regulus. You may have to use binoculars, but on those early September days, and on the 8th, Mercury and Regulus should be at their apparent closest to each other. You may want to know (but maybe not!) that in these early days of September, Mercury will show us an 8" (arc-second) disk and will only be about one-third phase; but by the 14th of September, the disk size is down to 6" arc-seconds, but the phase is waxing to almost 90%.

Be warned (or enlightened) - we experience a full moon on September 12th! This will be named the 'Harvest Moon' (generally), and on September 14 (Wednesday), the Moon will be at its apogee point for the month- and that distance is 406,065 Km, or 253,790 Miles.

The morning Zodiacal Light will make its presence near the end of the month in our eastern skies, and this should last for about two weeks. In order to catch a view of this 'false dawn' phenomena, you'll need to be observing from a dark site.

The September New Moon will occur on Tuesday, September 27 at 4:09 AM (Arizona time), and that's the same date that the minor planet 8353 Megryan makes it closest approach to Earth.

For the many deep sky observers and imagers here in Arizona, keep on alert for any new or reported Supernovae- a current one in M101 (2011fe) has caused some excitement and folks looking for even brighter ones; they are indeed being found quite regularly- and that's a good thing.

Planet Views - The views of Jupiter continue to impress me no end! Opposition is next month, but for now, the planet and its visible satellites are just spectacular. On September 14 and into September 15, take a telescopic journey to witness the very infrequent display of eclipse happenings between Jupiter and it's satellite Ganymede (note - not 'shadow' events). This will start early in the evening, but will continue into 9/15). You can find more details online! Jupiter is the planetary king of the solar system and reigns rarely challenged. A fading challenge, now close to being lost in the evening's Sun's glow, is Saturn. By mid-month, Saturn will visually be lost to us until it re-emerges in the morning sky in late October.

All of the above is really just a 'microcosm' of September astronomy events: I will finish off this month in listing below just a few of the grazing and asteroidal occulations that are also occuring in September within Arizona. I find so many of these events listed on the IOTA web pages, and I take part in some of them here in southeastern Arizona. Below are just a few of the events here in Arizona for September. The link for IOTA has more detailed data and information.

GRAZING Occultations (Moon and a star) http://www.timerson.net/IOTA/

September 1, 2011 star ZC 1858
September 20, 2011 star ZC 861
September 21, 2011 star ZC 1010
September 21, 2011 star SAO 78514
September 22, 2011 star ZC 1142


ASTEROIDAL Occultations (asteroid and a star) http://www.asteroidoccultation.com
(These times are shown in Universal Time, as listed on the website) - for Arizona MST, subtract 7 hours

03 Sep 2011 , 11:57 UT 46 (270) Anahita
mag 12.2 2UCAC 39259065
mag 13.4 SW USA, Mexico

05 Sep 2011 , 06:15 UT 99 (95) Arethusa
mag 13.1 TYC 5706-03276-1
mag 11.2 W Canada, W USA, W Mexico

15 Sep 2011 , 08:51 UT 81 (338) Budrosa
mag 12.6 2UCAC 31964284
mag 12.5 USA, Mexico


Again, just a FEW samples, and don't feel threatened by the star or asteroid magnitudes listed; many successes are made with standard equipment and many events are conducted with brighter stars. If at all interested in learning more, don't hesitate to visit the linked sites and /or contacting me for more information! starhaven@palominas.com

That should do it for September, 2011 - If you feel I have missed something really great or know of an unusual event, let me know! Enjoy the night skies, but most of all, get out there to explore, discover, and enjoy before someone pollutes it even more! Believe me, they will.

--Doug Snyder (C/2002 E2)

Here is a very abbreviated blog update for the coming month of August! What with our southwest region monsoon season now appearing to be well underway and pretty much obliterating our usually pristine night skies, there is not much, astronomy-wise, to proclaim as "the event of the month!" Even the usually looked-forward-to Perseid meteors later in the month are being pretty much concealed by a full moon occurring on the same night as the predicted peak! But there is always the few that arrive in our atmosphere brighter than a 100% Moon, and let's hope that happens again this year.

The brightest asteroid, but not the largest, (4)Vesta, now has a traveling companion - the orbiting space craft known as Dawn. Images are being sent back to Earth in which the resolution per pixel of the image represents less than 1 mile- amazing! Well, (4)Vesta reaches opposition on August 5th at 3 am Arizona time, and it is also at naked eye visibility during this time - magnitude 5.6; brighter than any other asteroid (minor planet) in orbit in the main asteroid belt. It is currently in the constellation Capricornus. For more on (4)Vesta and the Dawn mission, check out the NASA Dawn Mission Website.

What am I forgetting here? I would really like some feedback on this monthly blog, whether it be good or bad! Let me know what needs to be included, or not!

Speaking of good, there is a public night at Patterson Observatory on Thursday, August 4 (weather permitting, of course), and it gets underway right after dusk. It would be so great to see several members of the Huachuca Astronomy Club out there supporting this operation and you can, but its not necessary, to bring a telescope - there are a couple of fine ones already at the observatory ready for instant use! Sure, the sky is not the darkest, but IT'S sky, and still offers the excitement of exploration and discovery. The folks that do visit the observatory really enjoy conversing with astronomers, amateur and professional.

On August 12, HAC is holding its monthly meeting at Cochise College, and the speaker this month is Tim Hunter; you will not want to miss his presentation; Tim is the owner of Grasslands Observatory over there in Sonoita, and among many other accomplishments, one of the co-founders of the IDA.

When you have the observing chance, check out the latest that's going on with Jupiter! It is a most dynamic planet, and more moons than you can shake a stick at! 63 of them at last count - how many can you see with your optics? And why are you missing seeing the other 59? Get bigger optics! You betcha.

See Ya Out Under The Stars,
Or You Know What's Good For You -

--Doug Snyder

We astronomers are 'blessed' with TWO New Moon dates here in July, 2011, the only month this year in which this occurs. By glancing at the July entries, you'll see that the first NewMoon falls on July 1st, and the second NewMoon occurs on July 30th - let's hope for fine observing weather, although we should be embedded well into our annual monsoon rain season. For some of us, the latter date of the second new moon, the 30th, falls about 1 day after a predicted favorable METEOR SHOWER this year, and I sure hope that this 'South Delta-Aquarids' does meet expectations. It is expected to peak during the morning hours of Friday, July 29, but it is also possible that the peak may occur later, as some have predicted for the morning of Saturday, July 30. Myself and I am sure others will be monitoring the activity on those days as well as surrounding ones. Most of the observed activity from this shower has been with moderate speed, say about 41 km/hr.(25 mph) and about 5 to 10 percent leave persistant trains, and expect to see about 15 to 20 meteors per hour. The radiant of the shower is a few degrees to the north of the magnitude 1.6 star Fomalhaut (which itself is not in the constellation Aquarius). Be sure to observe from as dark a site as you can get to.

Periodic Comet 123P /West-Hartley, which has a period of 7.6 years and reaches perihelion this month on day 04.47 is not expected to be a overwhelming comet event. It's distance in AU (Astronomical Units) will be 2.129 on or around that date and magnitude wise, it may reach into the mid 14's!

A second periodic comet also reaches perihelion this month, and that is Comet 69P Taylor; its distance is 2.271 A.U. and that occurs on July 17. Don't expect the magnitude on 69P to be any brighter. The orbital period for 69P is 6.95 years.

Also of note is that the planet Neptune turns 1 this month! That is, it completes it's first complete orbit since its discovery on September 23/24 1846. JPL has calculated that on Tuesday, July12, that is the appropriate anniversary date. You'll have to see the complete explanation in the 2011 RASC Observer's Handbook. Oh, but by the way, it takes Neptune 165 Earth years for one orbit.

Here is something different for amateur astronomers who want to try their hand at observing star/asteroid occultations: I have listed below just three of the several occultations visible in at least part of Arizona this month. For much more information on these very interesting events (IMHO), visit the link that I include below. If you are curious about more, you can also contact me at this email (starhaven @ palominas dot com) or call me at (520) 366-5788 and I'll be happy to discuss occultations! Well, An occultation is an event that occurs when one object is hidden by another object that passes between it and the observer.

http://www.asteroidoccultation.com/asteroid.htm

07 Jul 2011 , 08:57 UT 39 (834) Burnhamia
mag 12.6 2UCAC 25615667
mag 12.4


08 Jul 2011 , 05:57 UT 34 (2249) Yamamoto
mag 15.1 TYC 6270-00829-1
mag 11.1


18 Jul 2011 , 11:03 UT 28 (2479) Sodankyla
mag 17.9 HIP 18097
mag 7.6



That's if for JULY 2011. Please contact me or I'll see you under the Stars!

--Doug Snyder

This marks the sixth month update for the Sky Calendar and just in case someone needs the original download, the 2011 Sky Calendar PDF can be found HERE and it can be that easy to download! Thanks.

I don't find much to add or update for June 2011, but I will expand on a couple of entries that are included for the June block.

First up is some information about the double star system Porrima, in the constellation Virgo. This information is brought to you via WIKIPEDIA, The Free Encyclopedia: "Gamma Virginis is a binary star, consisting of two stars of approximately equal apparent magnitudes 3.48 and 3.50, and of spectral type F0V. With an orbital period of 168.93 years it was an easy object for amateur astronomers until the beginning of the 1990s, but now the smaller apparent distance between the stars requires a larger telescope. The last time they were at periapsis was in 1836. The distance will again be wide enough in 2020 to view with a small telescope. The star system has a combined apparent magnitude of 2.9. The system is 39 light years away from the Sun.

As Gamma Virginis is close to the ecliptic, it can be occulted by the Moon and (extremely rarely) by planets."

Since Saturn is just about a half degree away from this system during part of June, it is quite easy to view both celestial wonders. At the beginning of 2011, the reported separation of the two components of Gamma Virginis would have been only 1.59 arc-seconds at a position angle (PA) of 19 degrees. At the start of the year 2012, the separation will be at 1.78" (arc-seconds) and a PA of 14 degrees. GET IT DONE!

My second 'touch-up' for June is the meteor shower named the June Boötids occuring on June 27; this is a favorable year as there is only a 12% moon, but the predicted activity is quite unknown as the ZHR variability ranges from 0 to 100+ ! This shower's parent comet has the designation 7P, or Pons-Winnecke, and its last perihelion was in September, 2008. It has a period of 6.37 years, so it's next perihelion is calculated to be in January of 2015. The radiant area is uncertain, but most likely within northern Boötes.

Clear Skies & Unobstructed Observing,

--Doug Snyder

May could be the most rewarding month for observational opportunities, reports, sky photos, and clear skies! Well, wouldn't we be so lucky to have all those - in one month. Here in southern Arizona, there is an 'Extreme' drought ongoing, and as of this April 2011, it is well in place. Yes, time for some welcome rain... but more welcome in the daytime hours than messing up our 'clear' night skies. From my backyard observatory, I've been taking some 'sky quality meter readings' during the month, and they are pretty impressive if I do say so myself. The average nightly reading so far on my Unihedron 'L' version meter has been 21.40 (magnitudes per square arcsecond) and in comparison, within the city of Sierra Vista (relatively close-by), I generally may get a reading of 18.00 or worse - ouch, that's no night sky at all!

Observationally, wow - the May morning planets have the astronomical world all a tizzy. It seems that each morning, during or around twilight, brings a somewhat spectacular and changing view of our incredible solar system and the Universe.

From the McDonald Observatory in Texas:

"There's a planet pile-up in the east shortly before dawn this month. Venus - the brightest object in the night sky after the Moon - is the dominant player as the month begins, but Jupiter, which ranks right behind Venus, takes over by month's end. Mercury briefly joins them, but it's much fainter. Mars is also nearby, but it is closer to the Sun and almost impossible to find in the dawn glare."

I couldn' say it better myself. Check it out - the morning sky this month is worth every moment we can spend gazing upon it - either by yourself or with spouse, family, or friends! The planets Mercury, Venus, Mars, Jupiter have their own highlites during the ever changing conjunctions in May. It is possible that the May 11-12 time frame may present the best views, but I hope we all enjoy the entire month of the 'dancing planets'. It is a GRAND SHOW, probably the best planetary show for 2011 and don't hesitate to send an observing report on to our club's forum, the HACLIST.

FULL Moon occurs on May 17 at 4:09 AM (MST), and it is generally named Flower Moon. The New Moon is on 2 May at 11:51 PM.

The Best Meteor Shower for the month of May is the Eta-Aquarids and can possibly peak on the morning of May 6 at around 5 AM and this is a VERY favorable year for the shower as there will be no interfering moonlite. This shower can be active from April 19 through May 28, and rates as high, or higher, average 60 meteors per hour. Be under dark skies! The radiant is located in the 'Y-shaped' Water Urn asterism of Aquarius, so again, check it out and file a haclist report!

ASTRONOMY DAY - MAY 7: Wow, how can we not remark on this day? Saturday, May 7 - International Astronomy Day, and the HAC will be celebrating with so much going on at the campus of the U. of Arizona South in Sierra Vista, and also at Patterson Observatory!! This will be going on in the afternoon and evening hours of May 7, so don't forget - HELP the club bring astronomy to Cochise County and the Sierra Vista community. Solar observing, scale model Solar System, unforgettable views of SATURN, and craters of the crescent Moon. Folks, this is our astronomy, and you can help us bring it to everyone! It gets underway at 3 PM on Saturday, and if you can help, just come on out to the campus or the observatory at around 1 or 2 PM, and we'll have fun work for you or spouses and family members.

SKY PHOTO CHALLENGE!! For the month of May, I am offering a $50 award for the best sky photo that is submitted and is based 'roughly' on an astronomical theme. It can be a night time photo, a day time photo, twilight or whenever, and can be submitted either in print or digitally (preferred) - either way, you can submit by sending it to:

P.O. Box 981
Palominas, Arizona 85615

Or you can attach it to a submittal on the club's HACLIST (nice photo attachments are now accepted), but be sure to include name and some details! You have to know how to send in a HAC report on the haclist, but its not all that complicated. Another submittal method that some may want to use is just to email their related 'astro' photos to me at my personal address . If this works out, this monthly photo opportunity for HAC may be extended further into 2011. Submitted photos/images will, or should, be posted on the HAC website . I do the judging, but don't worry - I am so, so fair as most of you know. Some others have not quite realized that yet.

That's it for May, 2011 - its going to be a astronomical month, so enjoy and share, and participate along with hopefully ALL folks who read this blog and either belong to the HAC or want to join the HAC or need to join the HAC. Don't forget to submit an 'astro' related photo - don't tell me you can't use $50. That's what it costs me for a tank of gas now!

--Doug Snyder

Thank goodness for spring time here in the desert - even though we're still sustaining a major drought here in this part of the state, the morning, afternoon, and evening temps are a refreshing turnaround from the record frigid days we were having just a few short weeks ago.

On the 2011 Sky Calendar listings for the month of April, I show as the monthly highlite the Opposition of one of the most unique planets in the Solar System, Saturn. In my humble opinion, it can possibly be one of the most beautiful and outstanding celestial bodies to be found in our galaxy. I would rank Earth as #1. Why? Have you seen what the Earth looks like when viewed from the Moon? As astronaut Jim Lovell said:

"It gives you in an instant, just at a position 240,000 miles away from it, (an idea of) how insignificant we are, how fragile we are, and how fortunate we are to have a body that will allow us to enjoy the sky and the trees and the water ... It's something that many people take for granted when they're born and they grow up within the environment. But they don't realize what they have. And I didn't till I left it."
        -- Jim Lovell, Apollo 8 and 13.

Well, on to the April skies of Arizona. Throughout the first weekend of April, astronomers and other sky gazers in Arizona and around the world will be embarking on the annual exercise to view, sketch, image, and a myriad of obscure methods to enjoy the deep sky wonders known as the Messier 110. While some insist the count of objects is not 110, but somewhat less, the majority of observers stand by that count to declare complete success in the (Charles) Messier Marathon. Not every year is celestial 'friendly' either. Depending on the nights and early mornings in which objects may set or rise for our viewing pleasure, sometimes it is very likely that circumstances don't allow the 'fringe' objects to be detected. Such difficult deep-sky objects such as M74, M77 (Messier #74, Messier #77) in the evening skies and M30 (Messier #30) in the morning sky don't always cooperate due to the degree of evening or morning twilight and making those particular objects, and a few others, seeminly just out of touch for a visual reward. The Messier Marathon is indeed a worthy task where ever you attempt it, and whether you capture 110 celestial wonders, or just 50, it is quiet pleasure and long remembered. For our club (HAC), the marathon occurs on Friday, April 1 . Many members are looking forward to the challenge at one of our member's backyard observatory and grand horizons!

On Sunday, April 3, at 5 pm Mountain Standard Time (midnight, Universal Time), that is when the planet Saturn reaches Opposition (when Earth comes directly between a planet and the Sun). Opposition is usually the best time to be viewing any planet as the planet rises right around sunset, and sets at sunrise - hence, visible all night! One positive note for Saturn this year is that the Saturian Ring System is beginning to 'open' up (become more visually tilted from our viewpoint) and the continued 'opening' will only improve - except for a slight decrease in tilt by June, the year's end will see the tilt of the ring system up to 14.8 degrees. There are so many fascinating aspects to Saturn that I cannot begin to discuss them here. But, did you know that the current 'satellite, or moon' count for Saturn is up to 61 ! Yes, 61, and at least 8 are within an amateur's telescopic reach. Maybe more if they have one of those 'big boy' telescopes. Also, at opposition, Saturn's disk size will be at 19" (arcseconds) and it's magnitude at +0.4; with the expanded ring system included, the planet extends over 44". As people ALWAYS say when at the eyepiece and looking at Saturn, WOW!

METEOR SHOWERS IN APRIL: Well, as the saying goes, there is some good news and there is some bad news - I'll throw both of them together and let you decide. Historically, The LYRID's meteor shower that occurs in April extends from April 16 until April 26, with the peak occurring the night/morning of April 21/22. This year, 2011, there is a 'bad' moon rising - at about 11:30 pm or so, a pretty bright 78% illuminated orb will rise and be in the night sky for the remainder of the night. That is not good for trying to observe a meteor shower. However, if fortunate, the ZHR (Zenithal Hourly Rate) may be 18 or greater and any of the Lyrid meteors are generally fast movers, some quite bright, and a few have been known to leave persistent 'trains'. As usual, the best times to view meteors is after midnight local time. There is a minor shower that may be occurring on Saturday, April 24; this is the PI PUPPID's shower and it is primarily a southern hemisphere shower. They are known for slower, but bright members. Its radiant point is about 20 degrees south of the star Sirius.

MOON-ing: The full Moon occurs on Sunday, April 17 at 8:43 pm; it can be known as 'The Egg Moon', 'The Pink Moon', or 'The Waking Moon' or a variety of other traditional names. The Moon also reaches perihelion a few hours earlier, and at a distance of only 358,090 kilometers, or 223,806 miles.

PLANET News: Take note that during the latter part of April, the planets Mercury, Mars, Jupiter and Venus all start to enhance the morning eastern skies; in fact, on the morning of the 30th of April, the four planets will be gathering to the lower left of a narrow crescent Moon. Mercury will show as a 29% illuminated disk, Venus, an 87% disk, and Mars, a 99% disk. Jupiter will be illuminted at 100%. That could be quite a early morning sight!

Easter Sunday this year falls on April 24.

COMETS: No good observing news to report; several comets are telescopically observable, but most are fainter than magnitude 11. Later this year, and into early 2012, there is a possibility that the comet C/2009 P1 (Garradd) will become slightly visible naked eye. It is to reach perihelion in December of this year. But nothing exciting for April, 2011! Please, lets get out under the stars and discover a new bright comet that will soon grace our disappearing night skies!

In Closing, I really urge ALL to support and participate in local astronomy activities, whether at a local planetarium, observatory, or your own backyard observing location, and to speak out against the horrors, yes horrors, of light pollution. You cannot believe, or maybe you can, the legacy of the night that this country and the world is losing each and every day. AFTER EVERY DAMN DAY THERE IS LESS & LESS OF A NIGHT SKY. And there is no end in sight, only a 24hour world-wide sky glow.

Until next month, EYES UP, LIGHTS DOWN, LUMINARIES OFF, SHIELDS @ 100%

--Doug Snyder

The wind is picking up, and not being too kind to us open sky observers here in Arizona - at least in the southern part of the state, and near the end of February.

Welcome to the 2011 March updates. On the current version of the sky calendar, the first dated entry lists the perihelion (closest approach to the Sun) for Comet P/2003 S2 (NEAT), or otherwise known as 243P; that date, which was derived from it's recovery orbital elements, was March 3, 2011. The last observations that I have been able to find are from August, 2010, and it appears that the latest magnitudes of the comet range between magnitude 18 and 19 ! Certainly not what folks were expecting. At perihelion, the comet will be near a distance of 2.457 Astronomical Units. At athe same time, Earth's distance away is almost on the other side of solar system and as such, is 3.386 AU from the Comet. Its just too bad there has not been a nice bright comet visible in our neighborhood skies for many-a-year.

Moving on, both Jupiter and Mercury have a relative close encounter during the early days of March, of course both appearing in the western skies, and it seems like the best date for this is around the 12th or 13th. Take a Look! Both planets shine brighter than mag. -1 and both arrive at perihelion within two days of each other on the 16th and 17th (Jupiter). Another event in which Mercury is good at is reaching its greatest eastern elongation from the Sun, this time at 19 degrees on March 22. You will find it in the western skies at about a half hour after sunset, and at an approximate magnitude of 0 (zero). After this date, it will start to fade fast as it once again encounters the Sun's ravishing glow. Early in the month, look for Saturn rising in the evening skies about two hours after sunset, but earlier each night afterwards because in April, it reaches opposition. So by the end of the month (March), it will be rising shortly after sunset. We look forward to that!

The minor planet/asteroid (3)Juno will reach opposition on Saturday, March 12 at 0300 hr MST, and it's magnitude will be a non-blazing 8.9; you will find it in the south-western portion of the constellation Leo (near the 'border' of Virgo); although Juno is numbered ' 3 ' as an asteroid, in size it's closer to being ' 9 ' . Its diameter is 170 miles, or 274 kilometers. In comparison, (1) Ceres has a diameter of 957 km, and there are seven larger asteroids than (3) Juno. Oh, just for FYI, (1)Ceres is now considered a 'dwarf planet', and is the ONLY one found in the asteroid belt between Mars and Jupiter.

The 'astro' event of the month, or one that ranks right up there, is the Star Night at the Kartchner Caverns taking place on the evening of Saturday, March 26. This is at an Arizona State Park, and the park is right along State Route 90, a few miles south of Interstate 10, east of Tucson, and close to Benson. If you are an astronomer, amateur or professional, novice or advanced, come on down to this dark sky happening. The welcome mat is out for folks from Sierra Vista, Tucson, Phoenix, Benson, Willcox, and ALL over Arizona. The one held last September was very successful with over 200 folks in attendance and the State Parks folks really enjoy hosting the event. For more information, you can contact Mr. Bob Gent at the Huachuca Astronomy Club (RLGent at cox.net ), or refer to the latest here on the HAC website or the Arizona State Parks sites. Again, it's called the Kartchner Caverns Star Night. Let's hope the weather cooperates again.

On the calendar, the Spring Equinox is also mentioned - occuring on Sunday, March 20 this year. Finally, the Sun crosses the equator traveling into the northern hemisphere. In Arizona, this happens at 4:21 in the afternoon. Great! Also not to be ignored is the Full Moon of March; this will happen on the 19th at 11:10 am MST, but be sure to watch the moon rise later from your location - it is to be the largest Moon of 2011, as it reaches perigee (closest to Earth) at 12 noon; that distance at the time will be 356575 km (221,475 miles). This could be a fine photo opportunity also!

As much as possible, enjoy the night skies of March, 2011, and always, always, ALWAYS combat light pollution and keep your EYES UP!

--Doug Snyder

Hello Arizona observers - This is a blog update for the 2011 Sky Calendar and for events near the end of January and into February. As it seems that the Quadrantid Shower did little to present us with a significant brief burst of meteors, we're sure that somewhere in the world, at least for a brief time, the shower was impressive. Here, in Arizona, not so much. We look forward to July and the 'delta-Aquarids'.

A cold January ending will likely continue into February, but we'll grin and bear it. I guess for some in other areas of the U.S., Arizona seems like temperature paradise. For February, as shown on the sky calendar handout, the highlite of the month is the Zodiacal Light in the west. This will be more evident in the evening sky on and after Feb. 20th, and will last for about two weeks. It will appear as a large, softly radiant pyramid of white light with its base near the horizon and its axis centered on the zodiac. In its brightest parts, it exceeds the luminance of the central Milky Way. (the preceding description courtesy of 'The Observer's Handbook, 2011 edition). Before this 'light' however, there is an occultation of note (predicted) occuring on Feb. 4 (MST) at around 11:31 pm, and visible mainly within the southern regions of Arizona. This is the occultation of an magnitude 11.5 star in Cancer by the asteroid (minor planet) 2709 Sagan. Details can be found at the following link:

You can go to the link and see if you are in the path of this event and find more details. Asteroidal occultations are pretty neat if I do say so myself. I've been moderately successful with them.

Another possible good event in February is the meteor shower known as the 'Alpha Centaurids'. It is predicted to occur during the morning of Tuesday, Feb. 8 (MST), and there is to be little moon interference (Full Moon is on the 18th). But this shower, if it 'blossoms' in 2011, has a radiant well to the south (at about -59 degrees declination) and has shown a variable ZHR over the years. Meteors associated with this shower are usually fast and bright, with some leaving nice 'trains'.

Be sure to keep your sky calendar handy and your optics clean, whether its February or August. As events allow, this blog should continue. Comments welcome - email starhaven at palominas dot com

--Doug Snyder

For the first month in 2011, there are a few of the calendar events that may need more details. Of course, on January 3 at 1200 hours (MST), that is the time in which Earth reaches perihelion in it's orbit of the Sun. That distance, this year, is 147,105,721 kilometers; or if you prefer, 91, 407, 257 miles. This 'fact' was not included in the calendar, but may be of interest to someone out there!

One of the best possible meteor showers of 2011 may be happening early in the first month peaking during the morning hours of January 4th. The Quadrantid shower is expected to have a very favorable appearance, one reason being it falls on the same date as New Moon. The ZHR (Zenithal Hourly Rate) may be 120, but of course that's variable during the course of a night. In any case, if it's clear where you're at, and dark!, get outside and enjoy the show!

On the evening of January 9 at approximately 2049 hours (8:49 pm MST), a most unique event continues to unravel involving the planet Jupiter and two of it's largest moons. So unique in fact, it is the only occurrence during the entire year that involves the Galilean moons Calisto and Europa in which there is a transit of both across the face of Jupiter during the same time frame. It all ends at 2333 hours when Europa completes it's transit. This may be difficult to observe as satellite transits are generally more troublesome to follow than shadow transits. I could not uncover any double shadow transits occurring during normal viewing conditions in Arizona. If someone finds these to observe in January in Arizona, please let me know!

Both Mercury and Venus are morning planets.

The two astronomy public outreach events scheduled in January are all special in spite of cold winter weather expected. The third event, a club member star party, is one not to miss at Discovery Observatory West, a little south of Sierra Vista.

Until next month, here's wishing you clear skies & many fine starry discoveries! For any comments, good or bad- email starhaven at palominas dot com

--Doug Snyder