Thursday, January 28, 2016

observing, finally!

Today (Jan. 27) was the first clear day since New Year's, and I had a very satisfying session in the backyard.

I woke a half hour before dawn and went out back in my bathrobe with binoculars, hoping to catch the five planet alignment happening these next two weeks.  Jupiter, Mars, Saturn, Venus, and Mercury.  I found Jupiter well to the west and near a just past full moon; Mars was near meridian.  But the others were behind low clouds.  No chance for those, or for Comet Catalina.

This evening was another matter.  Both transparency and seeing were very good.  After dinner, starting around 7:15pm, I was on the patio with the 8-inch, looking at M42, the Great Orion Nebula.  A well deserved title.  At 48x and 1.7 degrees FOV, I contemplated the bright mottled central regions and the sweeping arcs of nebulosity spouting from it, and remembered Messier's drawing.  At 67x the nebula was strikingly more mottled and was tinted a faintly bluish green.  At 184x I could see the E & F stars in the Trapezium -- faint, but direct vision and no doubt about it.  More evidence of the excellent figure of the mirror.

I the toured some open clusters - M35, M37, M36, M38.  I could not find NGC 2158 near M35.  Using 67x with M37, I observed FU Aurigae in the same FOV as the cluster.  FU was slightly less red but brighter than the central red star of M37.  I remembered raving about this star a few weeks ago.  All the clusters were finder finds, a bit misty there, but very lovely in the eyepiece.

After attending to my nightly duties I came back out at 9pm to run through some AL lists and breathe the air of astronomy once again:

NQ Geminorum, carbon star, a dull red to yellow, with another yellow star 2x as bright to the NW.  It has a faint follower, widely separated.  An arc of 4 faint stars to NW in a fairly rich field.

W Canis Majoris: Appeared red in finder.  Orange-red, about 7.5 magnitude, in a rich field.  Its radius is 234 times the sun's and is more than 1400 light years away.

R Canis Minoris: Faint, weakly yellow.  Tough find.  It has a faint companion, widely separated to NNE.

BM Geminorum: Nice!  At the tip of a large arrow shaped asterism with 57 Geminorum at one end.  BM is small, orange.  Another string of stars trails off to the NW. 

Adhara = epsilon Canis Majoris: Wow!  Bright (+1.5 magnitude) and large A with small and much fainter close B (magnitude +7.5) to the south.  Lovely double (113x).  Wikipedia: "The A star is the brightest known ultraviolet source in the night sky....  4.7 million light years ago Adhara was 34 light years from the Sun, and was the brightest star in the sky with a magnitude of –3.99. No other star has attained this brightness since, nor will any other star attain this brightness for at least five million years."

Wezen: Bright, yellow-orange.  It is a relatively young star, 10 million years old, but has stopped fusing hydrogen in it's core and is on its way to becoming a red supergiant.  Once it has enough iron in its core it will collapse in a supernova.

NGC 2362, open cluster in Canis Major.  Pretty, triangular cluster with a bright star (Tau Canis Majoris) in the middle.  It is related to nebula Sh2-310 nearby, which I did not see.

VY Canis Majoris: Pretty pumpkin orange; close companion to N.  Another close double on edge of FOV.  Field rich with faint stars.  VY is a red hypergiant and one of the largest of this type: its radius would extend beyond the orbit of Jupiter.  It apparently has lost much gas to eruptions and is surrounded by nebulosity, which I again did not see (I need to try filters more).  Worth another look, as the bright knots of nebulosity were mistaken for companion stars in the past.

M78, EN in Orion: Two stars orientated N-S with a dim, hourglass haze around them.  With a waning gibbous moon rising I was surprised to see this one. 

Gliese 229: small nondescript star in Lepus in a string of two others.  A satellite passed through the FOV during the observation.  Very near galaxy NGC 2196 which was not seen.  Gliese 229 is a red dwarf only 19 light years away.  It is a flare star, undergoing random outbursts and increases in luminosity.  It has a brown drawf companion and a super-Neptune type planet in close orbit.

Cone Nebula in Monoceros.  With OIII filter appeared very indistinct as a dark triangular area with a milky faint wall of nebulosity to the N.  A few stars involved in the nebulosity.  It is an active HII star forming region; see the Hubble Space Telescope pictures for a better view!

Rosette Nebula in Monoceros.  Using 48x 1.7 degree FOV with OIII filter, appeared as a loose but evenly concentrated open cluster (NGC 2244), large mix of stellar magnitudes but <50 stars, surrounded by a thick doughnut of grey nebulosity.  Nebula has a more definite edge of grey nebula / dark sky to the N & E -- wider ring and more diffuse edge to the W.   It is an HII star forming region 5000 light years away, 50 light years in diameter.  It must be bright indeed to be seen so well from so far away.

Eskimo Nebula = NGC 2392.  At 48x with OIII appeared as a slightly bloated, hazy blinking star.  At 184x with OIII it was clearly a planetary nebula with a double shell, brighter in the middle with some mottling, and a fainter surrounding ring with diffuse edges.  No central star seen, but it has a close companion star to the N.

M1 = supernova remnant in Taurus.  I was very surprised to see it, as the moon was rising and I'm in a red zone light pollution.  at 67x it was a very faint (still direct vision, a little brighter with averted vision) elliptical cloud 3:2 WSE-ENE.

Procyon = alpha Canis Minoris: Big an beautiful.  Did not see white dwarf companion Procyon B (of course).  11.6 light years away, one of our closest neighbors; appears bright because of its closeness.

Pollux = beta Geminorum: Big and bright, slightly yellow.  It's an evolved giant star 34 light years away; an extrasolar planet discovered in orbit.

14 Monoceros: Faint close double near NGC 2254, Wow!  really pretty pairing.

Plaskett's Star: Really dense field of stars; AAVSO chart essential to find.  Rather non descript.  6600 light years away, it is one of the most massive binary systems known. 

I spent some time trying to split Sirius, but was not successful.  Will keep trying with this scope as the sky allows. 


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