30 May 2019
The twenty four Pişmiş open clusters make a delightful little observing project. A few of them are exquisitely bright and delicate, others appear as tiny glints of stars mingled with a faint hazy glow of unresolved starlight, and yet others appear as little more than a faint and tantalizing mistiness. They were discovered by Paris Pişmiş, a remarkable astronomer who played a significant role in enriching the field of astronomy.
Marie Paris Pişmiş de Recilas (1911-1999) was born on January 30, 1911, in Istanbul, the daughter of an Armenian family of great prestige in their community. She completed her high school studies at Üsküdar American Academy. She was one of the first women to attend Istanbul University. She enrolled in the Faculty of Sciences and earned a PhD degree in Mathematics in 1937. Her supervisors were Professors R. Von Mises and Erwin Finley-Freundlich (she served as an interpreter and research assistant to Freundlich). As a student, Paris worked at the Istanbul University Observatory.
In 1938 Pişmiş travelled to the United States to become an assistant astronomer at Harvard College Observatory for a year. However, with the outbreak of World War II it did not seem advisable for her to return to Turkey so she stayed on at Harvard until 1942 when she married Félix Recillas, a Mexican astronomy student, and they moved to Mexico to join the recently founded Observatorio Astrofísico de Tonantzintla in Puebla. Pişmiş worked there until 1946. In 1948, she moved to Mexico City where she joined the Observatorio Astronómico Nacional at Tacubaya, which was part of the Universidad Nacional Autónoma de México (UNAM). For more than 50 years, she worked at UNAM where she became Astronomer Emerita in what is now known as the Instituto de Astronomía..
Pişmiş’ primary interest was galactic structure. She carried out some of the first photometric observations of young stellar clusters and discovered a globular cluster and 20 open clusters. She also studied the effects of interstellar absorption in stellar associations on the observed stellar distribution. She sought to explain the origin and development of the spiral structure of galaxies and to discover a reason for the waves of their rotation curves, based on different stellar populations. In 1972, Pişmiş introduced Fabry-Perot interferometry to Mexico to study the velocity field of galactic emission nebulae.
During her lifetime she visited over 20 nations, giving astronomical lectures in any of six languages – Turkish, English, French, German, Italian and Spanish. In Mexico she supervised at least half a dozen PhD theses by graduate students at UNAM. She was a role model for women astronomers – of the approximately 80 astronomers at UNAM over the years, 25% were women. According to Dorrit Hoffleit (1907-2007) “she is the one person most influential in establishing Mexico’s importance in astronomical education and research”.
Pişmiş published her memoirs in 1998 under the title, Reminiscences in the Life of Paris Pişmiş: a Woman Astronomer (but alas, the book is long out of print and seems unobtainable).
Paris Pişmiş died in Mexico City on 1 August 1999.
Proof of her great commitment to her field can be seen in our southern skies… using the existing Schmidt plates of the Tonantzintla Observatory, she discovered 24 open clusters and 2 globular clusters, and published her Nuevos Cumulos Estelares en Regiones del Sur (New Southern Star Clusters) catalogue in 1959. Of the 24 open clusters, four had already been discovered: Pişmiş 1 (NGC 2568) was discovered by E.E. Barnard in 1881; John Herschel discovered Pişmiş 6 (NGC 2645) in 1834 and Pişmiş 9 (NGC 2659) in 1835; and Pişmiş 18 (IC 4291) was discovered by Robert Innes in 1901. The globular cluster Tonantzintla 1 (Pişmiş 25) is NGC 6380 which had been discovered by John Herschel in 1834, but Tonantzintla 2 (Pismis 26) was a new discovery.
Some time ago, when I was exploring the vast and spectacular tendrils of the Vela SNR, small slews of the telescope brought a treasure trove of other objects into view, so for the blog I wrote, I annotated an image of the region… and was dumbfounded to discover that ten Pişmiş open clusters could be seen in the image, with another half dozen just around the corner, so to speak. Here is the image with the Pişmiş open clusters annotated in yellow, although I couldn’t identify Pişmiş 10 (which consists of only five dim stars) on either the image or in the sky, so its label is merely in the rough vicinity.
16″ f4.5 Dobs; 200x, 228x and 333x
I have included Paris Pişmiş’ notes from her catalogue, as I found it fascinating to compare her notes with what I was seeing in the eyepiece.
Pişmiş 1 = NGC 2568 (Puppis)
RA 08 18 18.0 Dec -37 06 00
Mag 10.7 Dim 3′
Number of stars 30
Note: The bright stars seem aligned like chains.
A small, faint cluster consisting of about a dozen mag 12.5 and fainter stars. “The bright stars seem aligned like chains” and indeed they do… the brighter stars forming a curving NS arc, and a less obvious, fractured-looking NW-SE chain of fainter stars lie on the SW side.
RA 08 17 57.8 Dec -41 40 12
Mag 10.7
Dim 4.0′
Number of stars 100
Note: Very beautiful object, symmetrical
Albeit it faint and small, this cluster is beautiful in its symmetry… it appears as a faint round patch of soft misty unresolved starlight with a mag 12.5 star its western edge.
RA 08 31 15.60 Dec -38 39 28
Mag –
Dim 6.0′
Number of stars 50
Note: Bright stars in the shape of a crown
I can’t see the shape of a crown, the cluster appears as a faint scraggy-shaped haze of misty pearl-coloured unresolved starlight with a mag 12 star lying the western edge. With averted vision, a few tiny faint stars glint in and out of view.
RA 08 34 40.80 Dec -44 29 42
Mag 5.9
Dim 25′
Number of stars 45
Note: The nebula appears in the lists of Gum (16) and Cederblad (106g); elongated as the cluster.
This is a gorgeous scattering of a few beautiful bright mag 8-11 stars that lie in a elongated N-S direction with a few fainter stars scattered around. With the OIII filter and averted vision, I can make out a very faint, very fragmented streak of very pale nebulosity running almost parallel to the cluster on its western side. (An OIII filter is an absolute must while observing the Vela SNR tendrils; without the filter, I failed to see anything of the entire remnant except for a slight hint of a filament here and there with averted vision.)
RA 08 37 39.84 Dec -39 34 48
Mag 9.9
Dim 2.0′
Number of stars 10
This very attractive little cluster lies on the northern shores of the very attractive loose sprawl of stars of mixed magnitude that make up the Ruprecht 64 open cluster. It has ten stars displaying attractive patterns: there is a close pair in the centre of the cluster, another brighter close pair to the south, a tiny triangle of faint stars on the north western edge, and a tiny arc of three faint stars on the eastern edge.
RA 08 39 02.88 Dec -46 13 58
Mag 7.3
Dim 1.5′
Number of stars 15
Note: Two pairs of doubles, including the brightest star
A beautiful bright little cluster! It has around a dozen stars compactly packed into a stunning bright knot. The four brightest stars form a striking right-angled triangle and include the “two pairs of doubles, including the brightest star” – the right angle itself is an eye-catching pair of close bright white mag 9 stars, and the other double lies to its south, and is a slightly less tight white mag 9.4 star with a white 10.6 companion. The fourth star, a mag 9 star lies west of the right angle double. The other fainter stars lie haphazardly scattered around these four bright white stars. Lovely!
RA 08 41 12.00 Dec -38 42 25
Mag 7.3
Dim 3.0′
Number of stars 35
This cluster appears as an extremely small, extremely faint dusting of misty unresolved starlight, that I picked up with averted vision. It only just barely stands out as a cluster among the rich field of stars.
RA 08 41 39.60 Dec -46 16 01
Mag 9.5
Dim 3.0′
Number of stars 25
Note: Is in a region of high absorption
This small cluster appears as a small, soft pearly glow of unresolved starlight with the glints of a few faint stars resolved across it. A fuzzy-looking mag 11 star lies at the south eastern edge of the cluster. With the OIII filter, a very thin, and very faint arc of nebulosity lies to the east, its open side to the west wherein lies this cute little cluster.
RA 08 42 34 Dec -44 52 48
Mag 10
Dim 3.3 × 2.2′
Number of stars –
Note: It includes −44° 4728 ; open cluster
A pretty little cluster; bright, compact group with just over a dozen approx. mag 12 stars sprinkled across a lovely gathering of fainter stars in an oblong shape, elongated NE-SW. The stars appear to be more concentrated in the SW end of the oblong. With the OIII filter there is a very faint blurry patch of nebulosity to the west and a nice, albeit also very faint, thin roughly E-W streak of nebulosity to the SE of the cluster.
RA 09 02 38.16 Dec -43 38 09
Mag 10
Dim 1.5 × 3.5′
Number of stars 5 Nebulosity
Note: It includes 48° 4354
I searched diligently for this cluster but couldn’t make out anything that even began to resemble this very sparse little cluster.
RA 09 15 52.99 Dec -50 01 00
Mag –
Dim 2.5′
Number of stars 20
This is a lovely little cluster! Three mag 12-13 stars in a tiny arc and embedded in a mist of small stars and unresolved starlight, appearing to dangle from the gorgeous blue-white mag 9 supergiant HD8077 like a piece of delicate filigree dangling from a diamond.
RA 09 20 00.30 Dec -45 06 54
Mag 9.7
Dim 5.0′
Number of stars 20
Note: Circular symmetry, beautiful object
This cluster doesn’t have a circular symmetry to my eye, although it is beautiful in an understated way. It appears as a scraggly, irregular-shaped cluster with pretty orangey mag 6.7 HD 80777 as its SE edge, a nice triangle formed by three mag 12 stars at its northern end, and another mag 12 star at its western edge. The rest of the stars are fainter, most of them lost in the soft background glow of unresolved starlight, except for a little grouping of mag 13 and 14 stars that lie near the eastern edge of the cluster.
RA 09 22 06.96 Dec -51 06 07
Mag 10.2
Dim 2.0′
Number of stars 30
Note: Five bright stars inside 1′
I confess that I have always found it difficult to define exactly what bright scattered stars comprise the open cluster NGC 2866 as the field itself is rich in stars of mixed magnitudes. But there is no doubting the cluster’s little heart… very pretty little Pişmiş 13. It contains over a dozen mag 12 and fainter stars against a beautiful irregularly round patch of unresolved starlight. It has two nice pairings – a close double at the north of the cluster, and another close double on the east side of the cluster.
RA 09 29 52.80 Dec -52 46 48
Mag –
Dim 1.5′
Number of stars 12
Note: At the edge of the plate; on the dark background one suspects the existence of the weakest members
I didn’t manage to pinpoint this cluster, although there were three definite maybes… never a good thing! But it certainly is a gorgeous bit of stellar real estate to be scratching around in… chock-a-block with gorgeous stars! There were a number of very lovely bright stars scattered around, and the three small sort-of gatherings of fainter stars but I couldn’t determine which was the cluster.
RA 09 34 45.12 Dec -48 01 48
Mag –
Dim 5.0′
Number of stars 35
Note: Similar to number 12; circular symmetry
Unlike number 12, where I couldn’t see the circular symmetry, this faint glow of starlight did appear round – a hazily misty sheen of unresolved starlight against which a few tiny stars glinted in and out of view with averted vision.
RA 09 51 16.08 Dec -53 10 01
Mag 8.0
Dim 2.0′
Number of stars 12
Note: They are members −52° 3412 and −52° 3413 (double of comparable brightness)
Another exquisitely small open cluster – albeit faint, it has the most delicate teardrop shape with the tip facing SW. Its four brightest stars form a beautiful little chain along the teardrop’s southern edge, with the fainter members filling out the teardrop with a beautiful mistiness of unresolved starlight against which a couple of stars pop in and out of view with averted vision.
RA 11 01 04.08 Dec -59 49 04.8
Mag 9.4
Dim 0.6′
Number of stars –
Note: Quadruple star in nebulosity plus five faint stars; is the center of arcs that extend up 15′. Similar to NGC 2467.
This is a delightful little cluster – lying in a rich field of stars, it stands out well…. a delicate triangle of stars – the base of the triangle formed by a delicate E-W trio of stars, with the apex north of them; itself a nice mag 10.5 star with a very faint close companion. The cluster itself lies in a faint haze of nebulosity that has no defined edges and simply dissolves away into the star-rich background. No particular contrast gain with the UHC filter.
RA 13 36 55.92 Dec -62 03 54
Mag 9.7
Dim 4.0′
Number of stars 35
Note: Six stars brighter than 10.5m to 12m; the brightness of the members gradually declines
A pretty little cluster, a triangular shaped cloud of starlight with its apex at the NE and marked by a mag 10.9 star. A handful of mag 11-12 stars are scattered across the haze of unresolved starlight, and there is a pronounced dark patch on the cluster’s NNW side. The stars appear to be more concentrated in the SW base of the triangular shape.
RA 14 30 36.00 Dec -60 53 06
Mag –
Dim 3.0′)
Number of stars 60
This is an enchanting little cluster, not for its appearance, but for its location… it lies between Alpha and Beta Centauri; stupendous Alpha Centauri around 1.1′ to its ESE, and with the gorgeous large, fairly rich open cluster NGC 5617 lying to its NW. A noticeable triangular asterism points from NGC 5617 at Pişmiş 19… indeed, this small faint cloud of misty unresolved starlight appears to dangle to the SE from the star at the apex of the triangle, a mag 9 star with a very close mag 10.5 star to its south.
RA 15 15 23.04 Dec −59 04 01
Mag 7.8
Dim 4.5′
Number of stars 12
Note: The five brightest stars, inside 0.6′
This little cluster reminds me that not everything has to be blazingly beautiful to be beautiful… this small and delicate is utterly gorgeous! Four mag 8.2 – 11 stars are arranged in a tight little box-shape towards the middle with rest of the fainter stars spilling out from the boxy middle in a couple of gorgeous starry rays, the longest of which points to the northwest. Lovely rich starry background.
RA 15 16 44.40 Dec −59 39 18
Mag –
Dim 2.0′
Number of stars –
Note: At the edge of the plate
This tiny little cluster appears as a small, bright, tight little knot of stars, set against a very small faint cloud of mistily unresolved starlight against which glints one tiny, faint star to the east.
RA 16 14 13.20 Dec -51 51 54
Mag –
Dim 4.0′
Number of stars 30
Note: Seven of the brightest stars in a suite aligned in declination. Multiple star?
A very unusual cluster! The “seven brightest stars in a suite aligned in declination”… I can see four mag 12-13 in a row, along with one more to the east towards the northern end of the row. The rest of the cluster appears to be lost in a faint circular glow of unresolved starlight around the ‘suite’. The attractive orangey star, HD 145542 lies to the SSW.
RA 16 23 58.08 Dec -48 53 31
Mag –
Dim 1.0′
Number of stars 15
Note: Very faint
Alas, “very faint” translated to “not visible” in my telescope. But oh my, a stunningly beautiful field in which to search for a very faint cluster!
RA 17 24 43.01 Dec −34 12 23
Mag 9.6
Dim 2.0′
Number of stars 15
Note: Inside a condensation of the big nebula around NGC 6557
It appears that in her note, Paris did what we all tend to do… stuck a wrong digit into an NGC designation: NGC 6557 is a galaxy in Octans (18h21m24.8s -76°34’59”) whereas her striking little cluster lies within NGC 6357. Without a filter, the cluster is beautiful; a very pretty double star (mag 11-12) double star; the star to the east appearing fuzzy, and with a few very faint stars popping in and out of view to the north of the double. A very faint mist of nebulosity can be seen to the north of the cluster – and it responds significantly to the OIII filter, appearing as a very nice WSW-ENE elongation of nebulosity that is quite a bit brighter in the middle, due north of the double.
RA 17 34 28.00 Dec −39 04 09
Mag 11.5
B * V m 17.0
HB V m 19.5
Diam 3.6′
Class –
This is a very tough globular! Lying in a lovely star-rich field, it is very, very faint, very small, has a very low surface brightness, is very diffuse, has no central concentration, and to boot its feeble glow is swallowed up the glare from a mag 10 star on its SSW edge, which makes it even more difficult to see. I could only pick it up with averted vision, and even then it tended to disappear and reappear.
RA 17 36 10.5 Dec −38 33 12
Mag 12.2
B * V m –
HB V m 18.2
Diam 2.2′
Class –
This globular is exceedingly tough! I only picked it up with averted vision after a long, concentrated look, and even then I couldn’t hold it; the tiny, incredibly faint glow, so diffuse it was almost transparent, flickered in and out of view in a maddening way – more out of view than in.
Copyright © Susan Young 2017