A Crescent Venus and a Crescent Moon

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A Crescent Venus and a Crescent Moon
Posted by DaveMitsky on Monday, December 09, 2013 3:34 PM

Since the time of an accident I suffered in July, I've been unable to do much telescopic observing.  I can't drive and need my wife's help to use even one of our small telescopes, as we did on Wednesday evening to observe Venus.

However, while my wife was away on Saturday evening, I managed to set up and train my "grab-'n-go" 80mm f/5 Orion ShortTube 80 achromatic refractor on Venus, with the lens cap aperture stop in place to reduce chromatic aberration, and then on Moon, without assistance.  

Venus had increased in apparent size to almost 42 arc seconds and was shining at magnitude -4.9.  As I did on Wednesday, I employed my 8-24mm Vixen and 3-6mm Tele Vue Nagler zoom eyepieces.  I was able to definitely make out the 25% illuminated Venus as a crescent at 17x, the 24mm setting on the Vixen zoom.  I worked through the Vixen's entire range of magnifications (17 to 50x) and then inserted the Nagler zoom, stopping at each focal length for a look.  The 3mm click stop setting (133x) produced a fairly large image of the waning crescent planet.  The best view was at 5mm (80x).

The 31% illuminated waxing crescent Moon grew increasingly hard to see as hazy clouds began to dominate the southwestern sky.  I removed the lens cap aperture stop to brighten the view a bit.  Using the Nagler zoom at magnifications of 67 to 133x, I noted lunar features such as the craters Petavius, Atlas, and Hercules and maria such as Mare Crisium and Mare Tranquillitatis.

Dave Mitsky 

Sic itur ad astra!

Chance favors the prepared mind.

A man is a small thing, and the night is very large and full of wonders.

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Posted by DaveMitsky on Wednesday, December 11, 2013 3:16 PM

Images of the two celestial bodies taken on that date are posted at http://spaceweathergallery.com/indiv_upload.php?upload_id=90952

Dave Mitsky

Sic itur ad astra!

Chance favors the prepared mind.

A man is a small thing, and the night is very large and full of wonders.

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Posted by DaveMitsky on Thursday, December 12, 2013 2:54 PM

My wife and I observed Venus again on Tuesday evening.  The 22% illuminated Venus had increased in apparent size to almost 44 arc seconds at the time.  As on the previous Wednesday and Saturday evenings, I used my 8-24mm Vixen (17 to 50x) and 3-6mm Tele Vue Nagler (67 to 133x) zoom eyepieces and 80mm f/5 Orion ST80 refractor to view our "sister" planet.

Prior to observing Venus I witnessed a nice pass of the ISS.  The space station reached a peak magnitude of -2.1 as it crossed the sky from the south-southwest to the east.

Dave Mitsky 

Sic itur ad astra!

Chance favors the prepared mind.

A man is a small thing, and the night is very large and full of wonders.

  • Member since
    April, 2012
  • From: North Carolina east coast USA
Posted by stepping beyond on Sunday, December 15, 2013 8:42 AM

That sound like ya.ll had a wonderful time, yall got skills. I've only been able to view the ISS through my Z10 with my 9mm Z100, I finally captured my first video of Venus "WOOHOO" with a SSUE ll Celestron eq80 f/11 refractor w/ motor. I've only seen the ISS in the N to E at around 930pm est., what time were you viewing the ISS in the Sw? I sure would like to try and view it in that direction of the sky and at that mag.

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Posted by DaveMitsky on Monday, December 16, 2013 3:33 PM

Evening satellite passes occur much earlier during the winter months. The ISS pass that I mentioned began at 5:34:09 p.m. EST in the south-southwest, culminated at 5:37:07 p.m. EST at an altitude of 29° and a magnitude of -2.1 in the southeast, and ended when the ISS entered the Earth's shadow at 5:39:12 p.m. EST at an altitude of 16° in the east.

You should consult http://www.heavens-above.com or http://spotthestation.nasa.gov/ for the times and directions of ISS passes.

Dave Mitsky

Sic itur ad astra!

Chance favors the prepared mind.

A man is a small thing, and the night is very large and full of wonders.

Moderator
  • Member since
    July, 2001
  • From: PA, USA, Earth Moderator
Posted by DaveMitsky on Tuesday, December 17, 2013 3:26 PM

By the way, along with observing Venus with my ST80 again, I witnessed an even better ISS pass on Thursday evening.  It began in the southwest, reached a peak magnitude of -3.3 at the zenith in the southeast at 5:37 p.m. EST, and entered the Earth's shadow in the northeast.

I also saw a flare from Iridium 56 in the south at 5:46 p.m. EST, as well as a flare from an unidentified satellite in the northeast.

Dave Mitsky

Sic itur ad astra!

Chance favors the prepared mind.

A man is a small thing, and the night is very large and full of wonders.

Moderator
  • Member since
    July, 2001
  • From: PA, USA, Earth Moderator
Posted by DaveMitsky on Tuesday, December 17, 2013 3:39 PM

Venus was only 17% illuminated when I observed it again yesterday evening*.  It will continue to wane in illumination and wax in apparent size to more than one arc minute, as it approaches inferior conjunction. Venus will disappear into the glare of the Sun by the second week of January.  Inferior conjunction occurs at 12:00 UT on January 11th.  Venus will be five degrees north of the Sun at that time.

http://cs.astronomy.com/asy/observing/f/33/t/59249.aspx

Dave Mitsky

Sic itur ad astra!

Chance favors the prepared mind.

A man is a small thing, and the night is very large and full of wonders.

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