Arizona Summer Doldrums

Updates to this blog have been far and few between. There are lots of reasons for this but a major culprit is the recent stretch of inclement weather here in southern Arizona. I usually blog about objects I can observe but there has been no observing here for close to a month.

The months of July and August are usually the height of the Arizona summer rainy season, or monsoon. This year is no different. Though the ramp-up to actually rain in Tucson was slow, the nights have been consistently cloudy for weeks. As a result I have not made any new comet or meteor observations and even my automated cameras have only been able to catch the rare meteor between the clouds.

Don’t get me wrong, I’m not complaining. My Bachelor’s is in Atmospheric Science and I love the weather. It’s just I spend less time thinking about observational astronomy this time of the year. As a result, I haven’t had much to write on the blog.

Still I am looking forward to at least a clear evening or two to set-up my latest meteor camera. For the past 2 years I’ve been using PC164C and PC164CEX-2 cameras with 4mm f/1.2 lenses. These cameras are relatively cheap but do not have the sensitivity of cameras used by other video meteor observers. Last week I purchased a Watec 902H2 Ultimate which I plan to use with a 6mm f/1.4 lens. The increased sensitivity and larger aperture lens should allow the detection of more meteors, perhaps even twice as many. So here to a clear evening or 2 and some clear nights during the upcoming Perseids.

June 18/19 to 29/30 Meteors

This post brings my video meteor observations up till the end of June. The end of June was hit-or-miss in Tucson. Though the monsoon was still far to the south and east, it was close enough to spread cirrus over southern Arizona from time to time. As a result, many nights were hindered by persistent cloudiness.

The only “big” event of note was a predicted increase in the rates of the June Bootids (JBO) on the evening of June 23. This shower usually produces very low rates of meteors though on occasion it can put on quite a show (1916, 1998, 2004). This year the Earth made a rather distant approach to a number of dust trails produced by Comet Pons-Winnecke in 1819, 1825, 1830 and 1836. Coincidentally, 1819 was the year of Pons-Winnecke’s discovery.

Peter Jenniskens reported on CBET 2357 that European and American observers did detect a small increase in the rates of the June Bootids. Still even at its best rates were only 5 per hour and most people would have seen much less due to the nearly Full Moon. Here in Tucson most of the activity was over by the time the sky darkened. Anyway the clouds were in force that night so I wasn’t able to detect any JBOs near the peak though I did detect a solitary JBO a night earlier.

Obs  Date(UT)      Time    TOT SPO ANT JBO DPI FOP
TUS  2010-06-30   00h19m    1   1   0   0   -   0
TUS  2010-06-29   07h38m    7   6   1   0   -   0
TUS  2010-06-28   03h29m    9   8   1   0   -   0
TUS  2010-06-27   07h50m    8   7   1   0   -   -
TUS  2010-06-26   00h00m    Clouds ...
TUS  2010-06-25   00h50m    2   2   0   0   0   -
TUS  2010-06-24   02h09m    4   2   2   0   0   -
TUS  2010-06-23   07h48m    15  11  3   1   0   -
TUS  2010-06-22   07h49m    12  12  0   -   -   -
TUS  2010-06-21   07h49m    14  12  2   -   -   -
TUS  2010-06-20   07h49m    13  12  1   -   -   -
TUS  2010-06-19   07h48m    16  13  3   -   -   -

TUS - Camera in Tucson operated by Carl Hergenrother
SDG - Camera in San Diego operated by Bob Lunsford
TotTime - Total amount of time each camera looked for meteors
TOT - Total number of meteors detected
SPO - Sporadics (meteors not affiliated with any particular meteor shower)
ANT - Antihelion
JBO - June Bootids
DPI - Delta Piscids
FOP - f Ophiuchids

In the Sky This Month – July 2010

This feature highlights a number of meteor showers, comets and asteroids which are visible during the month of July 2010.

July 2010 Highlights

* Total Solar Eclipse on the 11th for the South Pacific
* Venus, Mars and Saturn close in on each other in the evening sky
* Venus passes within 2° of bright star Regulus on the 8th
* Mars and Saturn within 1.8° of each other on the 30th
* Mercury has a mediocre evening apparition in July/August (great from SH)
* Mercury passes within 0.3° of Regulus on the 27th
* Comet 10P/Tempel 2 reaches small telescope brightness in the morning sky

Note: If anyone has pictures or observations of these objects/events and want to share them, send me a comment and I’ll post them on the blog.

Planets

Venus – Venus is the brightest “star” visible in the early evening (at magnitude -4.2). Low in the west it sets about 2 hours after the Sun. Maximum height above the horizon was reached over a month ago. As a result, Venus will appear to sink lower in the sky every night. Still, it will be well placed for easy observing for the next 2 months. If you are located south of the equator, this is a great apparition and Venus will continue to climb higher till late August. Regardless, of where you are located it will be hard to miss brilliant -4 magnitude Venus in the west an hour or 2 after sunset.

July 10 - Venus within 1.0° of bright star Regulus
July 14 - Moon passes within 5.5° of Venus

Mars – Mars moves rapidly from the constellation of Leo and into Virgo this month. Though fading from magnitude +1.3 to +1.5 it is still an obvious red beacon in the southwest right after sundown. It’s brightness is comparable to that of the other bright stars. Mars starts the month 23° from Venus and 15° from Saturn. By the end of the month, Mars will have caught up to Saturn. Venus isn’t far behind and all three planets will share the same part of the sky in August.

July 16 - Moon passes within 5.6° of Mars
July 30 - Mars and Saturn within 1.8° of each other

Saturn – This month Saturn is located in Virgo and visible in the southwest during the early evening hours. At magnitude +1.1 it is slightly brighter than Mars. The two will be within 2° of each other at the end of the month. Telescope users should note that Saturn’s rings are still within a few degrees of edge-on.

July 16 - Moon passes within 7.4° of Saturn
July 30 - Saturn and Mars within 1.8° of each other

Jupiter - Jupiter once again returns to sight as a brilliant star in the east-southeast before dawn. The magnitude -2.6 planet will get brighter and better place for observing over the next few months. Last year Jupiter made a series of close approaches to Neptune. This year Jupiter will do the same for Uranus. All month long Jupiter will be located within 2-3° of Uranus.

July 3 - Moon passes within 6.5° of Jupiter
July 31 - Moon passes within 6.6° of Jupiter

Mercury - Mercury will start the month too close to the Sun for observation. By mid-month, it starts to peak above the western horizon after sundown.  The apparition is a great one for southern hemisphere observers but a so-so one for northern observers. The

July 12 - Moon passes within 3.9° of Mercury
July 27 - Mercury passes within 0.3° of bright star Regulus

Meteors

Meteor activity should really pick up in July. The year is usually split in 2 with January through June having low rates with few major showers while July through December (really through the 1st week of January) have high rates with many major showers.

Sporadic Meteors

Sporadic meteors are not part of any known meteor shower. They represent the background flux of meteors. Except for the few days per year when a major shower is active, most meteors that are observed are Sporadics. This is especially true for meteors observed during the evening. During JuLy, 10-16 or so Sporadic meteors can be observed per hour from a dark moonless sky.

Major Meteor Showers

No major showers are active this month.

Minor Meteor Showers

Minor showers produce so few meteors that they are hard to notice above the background of regular meteors. Starting this month, info on most of the minor showers will be provided on a weekly basis by Robert Lunsford’s Meteor Activity Outlook.

Additional information on these showers and other minor showers not included here can be found at the following sites: Wayne Hally’s and Mark Davis’s NAMN Notes, and the International Meteor Organization’s 2010 Meteor Shower Calendar.

Comets

Naked Eye Comets (V < 6.0)

None

Binocular Comets (V = 6.0 – 8.0)

None

Small Telescope Comets (V = 8.0 – 10.0)

Comet 10P/Tempel 2

’10P’ says it all. This was only the 10th comet to be observed at a 2nd apparition meaning we’ve been following this comet for a long time. Discovered by prolific German comet discoverer Ernst Wilhelm Leberecht Tempel in Marseille, France on July 4, 1873, Tempel 2 has been observed at nearly every return since then. The comet’s current orbit brings it to within 1.42 AU of the Sun on July 4 and to within 0.65 AU of Earth in late August.

The comet is currently at a brightness of 9.0 to 9.5 magnitude and should brighten by another half magnitude this month. This is a large diffuse object so it will be more difficult to see than your average 9th magnitude comet or deep sky object. From my moderately light polluted backyard and 12″ telescope, the comet was a difficult object and was estimated to be magnitude 10.0. From a dark site and 30×125 binoculars, the comet was much brighter (magnitude 9.5), larger and easier to see. The added brightness was probably due to the dark site allowing me to see much more of the comet’s coma.

Tempel 2 is a morning object moving from the constellation of Aquarius to Cetus.

A finder chart for Comet McNaught can be found at Comet Chasing.

A nice collection of images can be found at the VdS-Fachgruppe Kometen (Comet Section of Germany) and Seiichi Yoshida’s Comet Homepage.

Comet C/2009 K5 (McNaught)

If you are looking for Comet C/2009 R1 (McNaught), which was a nice bright naked eye comet last month, this Comet McNaught isn’t the comet you’re looking for. C/2009 R1 is now too close to the Sun to be seen. The lesser known, and fainter but more observable, ‘Comet McNaught’  is Comet C/2009 K5 (McNaught). This will probably be the last month to catch a glimpse of this comet in backyard telescopes.

With perihelion back on April 30 of this year at a distance of 1.42 AU from the Sun, C/2009 K5 may still be bright enough to be seen in small backyard telescopes from dark sites. At mid-month it will be located 1.78 AU from the Sun and 2.47 AU from Earth.

Observations over the past month show the comet to be around magnitude 8.5. With the comet in full retreat from the Sun and Earth, it should fade rapidly from here on out. The comet will start the month between 8.5 and 9.0 but should fade to fainter than 10.0 by the end of the month. Due to its located in the northern constellations of Camelopardalis and Lynx, the comet can be seen at all hours of the night from high northern latitudes. It is best in the evening right after the end of twilight.

A finder chart for Comet McNaught can be found at Comet Chasing.

A nice collection of images can be found at the VdS-Fachgruppe Kometen (Comet Section of Germany) and Seiichi Yoshida’s Comet Homepage.

Asteroids

Binocular and Small Telescope Asteroids (V < 9.0)

(1) Ceres

Ceres is the biggest asteroid in the Main Belt with a diameter of 585 miles or 975 km. It is so big that it is now considered a Dwarf Planet. Classified as a carbonaceous (carbon-rich) Cg-type asteroid, there are suggestions that it may be rich in volatile material such as water. Some even propose that an ocean exists below its surface. Ceres is the other target of NASA’s Dawn spacecraft which is scheduled to visit it in 2015.

This month Ceres will be at opposition and brightest. The asteroid will start the month at magnitude 7.4 and fade to magnitude 8.1 by the end of the month. All month long it will be retrograding on the border of Sagittarius and Ophiuchus.

A finder chart (needs to be flipped upside down for Northern Hemisphere observers) can be found at the Royal Astronomical Society of New Zealand. Finder chart for Ceres from Heavens Above.

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