Archive for the ‘Observer’s Challenge Reports’ category

Epsilon Bootis – Double Star – W. Struve’s “The Most Beautiful One”

June 19, 2018

Observer’s Challenge object for June 2019:  

Epsilon Bootis:  Called “Pulcherrima” or “the most beautiful one” by Struve.

At one time, observing double stars was the most popular facet of amateur astronomy, however, I think we can all agree, this is not the case as of current.  Sad indeed!   I say….fortunate indeed is the amateur who discovers the joy of observing double stars.

Nothing is more beautiful than a close pair with vivid and contrasting colors, such as Epsilon Bootis.

Want to have some fun tonight?  You don’t have to be concerned with the brightening moon, or ambient lighting, but take a look and try the very challenging double star Epsilon Bootis.

Good seeing is definitely required to see the companion of Epsilon.  On many nights with less than good seeing, I’ve failed to see the companion, even with a 102 mm refractor, or a 10-inch reflector with an effective aperture of 4-inches, using an off-axis stop-down mask.  

It is an unequal double with the primary being magnitude 2.37 and the secondary at 5.12, with a separation of 2.9″ which makes this double difficult for many observers.

I see the colors as a beautiful yellow and a vivid blue, with a clean separation at 175x using a 102 mm refractor.

Quoting from Celestial Harvest by James Mullaney:

! Izar, Magnificently-tinted but tight pair. “Most beautiful yellow, superb blue.” Rather difficult in apertures under 4-inches.  A 3-inch at 150x shows two beautifully-colored diffraction disk nearly in contact!  ….called “Pulcherrima” or “the most beautiful one” by Struve.  JM

Many have seen the companion with a 3-inch, and from Webb, even a 2-inch, however, for me, it’s always been at least 4-inches of aperture.  What will be the smallest telescope which will allow you to see the companion?

After all….every amateur should attempt to see a double star called “the most beautiful one.”

Roger Ivester

 

NGC 4236, Extremely Faint Galaxy In Draco – May 2018 – Observer’s Challenge Report #110

June 7, 2018

To read the complete LVAS Observer’s Challenge report, click on the link:

MAY 2018 OBSERVERS CHALLENGE – NGC-4236

Rogers NGC-4236 Inverted b

10-inch reflector, and spending four hours in my attempt to see galaxy NGC 4236, of which the first three were unsuccessful.  However, during the forth hour, at well past 1:00 AM EDT, could glimpse an extremely faint, elongated NNW-SSE oriented blur of light as shown in my sketch.  The galaxy appeared featureless due to the extreme low surface brightness, and visible only intermittently with averted vision. 

Sky conditions were poor with a NELM of 4.9, which is about normal for springtime in the foothills of North Carolina.  There is a distinctive tilted half-circle of five stars, NNE of the galaxy which works well to assist in determining the exact location of this very faint galaxy, or better said, extremely faint galaxy. 

On the previous night, under the same conditions, using a 6-inch reflector, the galaxy was invisible, despite spending two hours in my search. 

Roger Ivester

 

Image by Dr. James Dire from Hawaii

NGC4236

NGC 4236 By Dr. James R. Dire

NGC 4236 is a faint, nearly edge-on barred spiral galaxy in the constellation Draco.  The constellation is often overlooked due to its low surface brightness.  The galaxy is relatively large in our sky, spanning 24 x 6.8 arcminutes. Its integrated magnitude is 9.63. NGC4236 is located 11.7 million light years away and is part of the M81 galaxy group.  It rivals M81 in size. However, M81 is 3 magnitudes brighter!

NGC 4236 is located “above” the open cup of the Big Dipper Asterism. Its distance above the cup is approximately the same as the distance between the two starts forming the top of the cup – Dubhe and Megrez.  NGC4236 lies just over a degree west of a linear trio of stars: 4, 5 and 6 Draconis.  Both 4 and 6 are 5th magnitude and are orange and yellow, respectively, while 5 is 4th magnitude and blue in color.

Despite its brightness and location near naked-eye stars, NGC 4236 can be very difficult to find, even with a GOTO mount.  The Image was taken with a 70mm f/6 apochromatic refractor using a 0.8x focal reducer/field flattener.  The exposure was a whopping 3 hours.  In the image, north is up and east is to the left.

In the image, the bright blue star on the left edge is 5 Draconis.  The orange star is 4 Draconic. Those two stars are separated by 40 arcminutes.  The smudge just above the center is NGC4236.  The exposure captured about half the actual length of the galaxy, essentially the galaxy’s central bar and the inner, brighter spiral arms.

To help identify the galaxy in the eyepiece, note the arc of three stars on the northeast side of the galaxy.  The top star is magnitude 8.3, while the lower two are magnitude 10.5.  There is also a magnitude 9.8 star on the south end of the galaxy’s major axis.  Seeing these four stars in the eyepiece allows one to center the galaxy in the eyepiece and then using averted vision to see the galaxy.

I viewed NGC 4236 this month in three telescopes.  The first was a 190mm f/5.3 Maksutov-Newtonian reflector using a 14mm eyepiece (71.4x).  I centered the galaxy using the four stars around it as described above.  Direct vision did not produce the galaxy. However, with averted vision I was barely able to make out the elongated shape of the very diffuse galaxy.

I next viewed the galaxy using an Orion 12-inch, f/4.9 Dob using a 20mm Televue Nagler eyepiece (75x).  The galaxy was just as difficult to see in this scope as the Mak-Newt.  This was probably because the Dob’s optics are nowhere as good as the Mak-Newt.  Plus, I later discover that the primary mirror on this astronomy club telescope was extremely dirty (I have since professionally cleaned it and recollimated it).

Finally, I viewed NGC4236 with a friends Orion 14-inch, f/4.6 Dob with clean optics and a good collimation. Through this telescope, the galaxy could be seen directly.  I could see about the same visual detail as in my image!   JD 

Messier 81 and M82: Galaxy Pair – Ursa Major – April 2018 – Observer’s Challenge Report #110

April 29, 2018

April 2018 Observer’s Challenge Report:  APRIL 2018 OBSERVERS CHALLENGE – M-081-82-1

Messier 81 (NGC 3031) Galaxy in Ursa:   10-inch f/4.5 reflector.  Sketch magnification; 12 mm eyepiece 95x.  

80 mm refractor at 33x, M81 is large, bright, mostly round with a brighter nucleus, and is nicely framed with companion galaxy M82.   

10-inch reflector at 95x, M81 is bright, large, well concentrated, elongated, but subtle, NE-SW.  Very bright nucleus, almost stellar.  Only on nights of excellent seeing and transparency can the spiral arms be seen from my moderately light polluted backyard.   RI   

Rogers M-081 Inverted

 

Messier 82 (NGC 3034) Galaxy in Ursa Major:  10-inch f/4.5 reflector @ 191x magnification.  Eyepiece:  12 mm plus 2.8x Barlow 

80 mm f/5 refractor:  Surprisingly bright, elongated with a lens shape, smooth texture at low magnification.  When increasing the magnification to 75x, the galaxy becomes very uneven and mottled, with two brighter knots toward the middle, and an outer elongated halo.  This galaxy is much fainter than it’s companion, Messier 81.

10-inch reflector:  Bright, very elongated, dark band in the central region is almost separating the galaxy, and is very easy at 114x, but really comes out at 200x.  At the higher magnification the galaxy becomes very mottled, and with a faint surrounding halo extending the length of the galaxy.  The NE and SW edges or tips of the halo are smooth.   RI   

Rogers M-082 Inverted

Notes from April 1978:  

It wasn’t until the mid-70’s when I acquired my very own telescope, a 4 1/4-inch Edmund Scientific reflector, a Palomar Jr. which was not my first choice, but the best my budget would allow.  

I’ll never forget one special night using this telescope. I was attempting to locate M81 and M82, two of the most beautiful galaxies in the heavens. By this time, the fabulous skies of my early years were gone. I’d moved to an area packed with houses and street lights, and the light pollution was very severe in my back yard.

Attempting to find even the brightest deep-sky objects under these conditions proved to be difficult.  I had tried on many occasions to find M81 and M82, without success.  I wanted to see this galaxy pair, which appeared so striking and beautiful in the magazines.

One night, while observing, time was running out.  It was already after 11:00 PM, and needed to get up early the next morning.  I used my hands in an attempt to block the ambient light from entering my eyepiece, and then it happened: A small, faint fuzzy object entered my telescope view.  I then nudged the scope slightly and then another…..finally M81 and M82.  What a beautiful sight!  I savored the view for the longest time and to this day and I can still feel that excitement.  RI 

Below:  Wide field image of M81/M82 and also NGC 3077, by Dr. James Dire at Wildwood Pines Observatory in Earl, North Carolina:

Image 1

 

 

NGC 2371-72 Planetary Nebula in Gemini – March 2018 Observer’s Challenge Report #109

March 29, 2018

Observer’s Challenge Report #109:  

MARCH 2018 OBSERVERS CHALLENGE – NGC-2371-72

Pencil sketch using a 10-inch reflector with inverted colors.  

Rogers NGC-2371 Inverted

NGC 2371-2372, Planetary in Gemini, nebula magnitude 11.3; central star 14.8.

This planetary is easy to discern with 10-inch reflector from my moderately light polluted backyard. At low power (57x) the planetary appears as a faint and small elongated nebulous patch.

When increasing the magnification to 207x, and with a UHC narrowband nebula filter, two distinctive lobes become visible, connected by a faint haze. The nebula is oriented NE-SW, with the SW lobe being brighter and having greater concentration. The bright spot becomes visible using averted vision, located on the NW side of the westernmost lobe.

When first observing this planetary almost twenty five years ago, I mistakenly thought this bright spot to be the 14.5 magnitude central star. It was, however, during a later observing session in 1998 that I realized the bright spot was not centrally located and far too bright to be the extremely faint central star. Another observation the following year confirmed this.

NGC 2371-72 has a similar appearance, but not nearly as bright as M76 (NGC 650-1) planetary nebula in Perseus.

Roger Ivester

 

NGC 2371-72
By Dr. James R. Dire

My image of NGC 2371/2 was taken with an 8-inch f/8 Ritchey–Chrétien Cassegrain with a Televue 0.8x focal reducer/field flattener yielding f/6.4. It was captured with an SBIG ST-2000XCM CCD camera and the exposure was 2.5 hours.

James NGC-2371

The planetary nebula has what appears to be a regular elliptical shell, divided into two main segments by a dark major-axis lane. The bright lobes are thought to be from bipolar flow from the central star. The cyan colored emissions come from O-III atoms. My image picked up two outer blue arc, most likely from a previous layer of gas ejected from the star in a similar bipolar manner.   JD 

 

The following photo by Mario Motta from Massachusetts using a 32-inch reflector. 

NGC2371

 

Inverted pencil sketch by Mike McCabe from Massachusetts.

100_7635G

 

Inverted pencil sketch by Jaakko Saloranta from Finland using an 8-inch reflector.

NGC2371

 

M41- Open Cluster in Canis Major-February 2018 Observer’s Challenge Report #108

March 9, 2018

FEBRUARY 2018 OBSERVERS CHALLENGE – M-041

Pencil sketch:  6-inch reflector @ 46x and 1.3º field of view: 

M41 Adjusted

Inverted colors

Rogers M-041 Inverted

Messier 41 (NGC 2287) at magnitude 4.5 is visible without optical aid. I often enjoy viewing this cluster with a pair of 7 x 21 mini-binoculars. It is easily located at about 4º south of Sirius, and NW of 6.0 magnitude 12 Canis Majoris.

A beautiful, but sparse cluster, very irregular shape, with several small chains of stars. The most noticeable star chains are on the SW and NE.

When using a 6-inch reflector, I can count ~60-70 stars. A small circlet of stars envelope the central region of the cluster. M41 contains the famous red star, known as the Espin star (HD 49091) magnitude of 6.9 and a K3 spectrum. The star was named after Rev. T.E. Espin (1858-1934.) I normally see this star as a deep-orange in color.    Roger Ivester

 

M41 image by James Dire:  

102mm (4-inch) f/7.9 refractor using a 0.8X focal reducer field flattener with an SBIG ST-2000XCM CCD camera. The exposure was 30 minutes. North is up, and east to the left.

M41

M41 is a beautiful galactic star cluster located 4° south of the bright star Sirius. The cluster can be seen naked eye from a dark site. It’s mag. 4.5 and is 39 arcminutes in diameter. It lies 2,350 light-years away

Aristotle noted M41 in 325BC as being a cloudy patch in the sky. The cluster was first cataloged by the Italian astronomer Giovanni Batista Hodierna in 1654, and then John Flamsteed in 1702. Charles Messier added it to his catalog in 1765.

M41 has about 100 stars. The brightest is a mag. 6.9 red giant star near the apparent center of the cluster, cataloged as HD49091. This K3 star has the brightness of 700 suns. The cluster is estimated to be 190 to 240 million years old and has a chemical composition similar to the sun.

The brightest star in the image is near the bottom edge, left of center. That star is 12 Canis Majoris, or HK Canis Majoris. HK is a mag. 6 blue giant star with a surface temperature of 18,000K. HK is only half the distance of M41 and thus is not a member of the cluster. The next brightest star in the image is the red giant HD49091, the red giant star near the center of the cluster.   James Dire 

 

Planetary Nebula IC 418 in Lepus:

February 14, 2018

Planetary Nebula IC 418, Lepus, magnitudes; nebula 9.3; central star 10.3

IC 418, also known as Spirograph Nebula.  The name derives from the intricate pattern of the nebula, which resembles a pattern which can be created using the Spirograph, a toy that produces geometric patterns (specifically, hypotrochoids and epitrochoids) on paper.  Source “wikipedia”

The following image:  Hubble Space Telescope

Spirograph_Nebula_-_Hubble_1999

I had a telephone conversation with Glenn Chaple yesterday.  Glenn mentioned PN IC 418 as a potential object for the 2019 observer’s challenge report. This planetary had been suggested by Joseph Rothchild at the most recent meeting of the (ATMoB) Amateur Telescope Makers of Boston. Richard Nugent also of Massachusetts sent me an email, saying he had recently observed this very interesting planetary, using a 20-inch reflector.  

It was only after checking my notes “this morning” (February 14th 2018) did I realize I had also observed this planetary…..25 years ago on (February 14th 1993) which is very coincidental.  

My notes (verbatim) from February 14th 1993:  

10-inch reflector: ” Looks like a blurred star. I would focus on stars outside the telescope field and then sweep back. The nebula was very apparent and obvious when using this method. Nebula fairly bright, mostly round and featureless.  Bluish in color and very small.  No nebula filter was used.”     

Skiff & Luginbuhl:  “This planetary is clearly visible in a 6 cm, appearing as an undistinguished mag. 9 star.  In 15 cm the central star becomes visible, while 25 cm shows it clearly at 200 x.  The surrounding nebula has a high surface brightness, making a poor contrast for the central star.”

RI 
 

NGC 1624 – Cluster (+) Nebula Perseus – January 2018 – Observer’s Challenge Report

January 12, 2018

Complete Observer’s Challenge Report:  Click on the following link.

JANUARY 2018 OBSERVERS CHALLENGE – NGC-1624

Pencil sketch using a 5 x 8 note card with the colors inverted:  10-inch reflector at 200x.  Roger Ivester

Rogers NGC-1624 Inverted

Image by James Dire from Hawaii

NGC1624

Image by Mario Motta from Massachusetts using a 32-inch telescope

NGC1624