On the night of May 11, 2021, I made three more sketches of multiples. This time I used my Bergess 157mm refractor on the CGEM mount and pier at the summit of Haleakala. The conditions were quite good with wind at 12 m/h, humidity at 11% and temperature at 45° F, (7.5° C). The Jet Stream was slow at 14m/s. This turned out to be an evening of near epic conditions! The sketches are linked to My Media.
Struve 2337, SAO 161630, WDS 18349-1442 in Scutum. Slew 1° 23’ almost due east, (95°), from Gamma Sct to locate this trio of stars. The 8th and 9th Mag. companion stars form an almost flat obtuse triangle with the primary at the ESE vertex. With a 2” Explore Scientific 18mm EP at 55X, 1.5° FOV, I plotted eleven field stars, identifying two on the sketch. With a 2” Explore Scientific 9mm EP at 111X 0.9° FOV, I plotted the trio with eight field stars. The primary has a Spectral Class of A0III, White. You can find the Lit. in Stelle Doppie here.
Here is a double triple that is observable at low power in a medium size, (< 6”), refractor! Dun 219, SAO 209545, WDS 17589-3652 and HJ 5000, SAO 209552, WDS 17592-3656 in Sagittarius, are located on the southwestern edge of the constellation. Slew 3° 44’ almost due west, (267°), from Eta Sgr, Sephdar, to locate this pair of objects. They can also be located 2° 18’ SSE, (154°), of M7, Ptolemy’s Cluster in Scorpius. In a low power FOV, (< .5°), just NNW at 323° at a distance of less than 6’ you will locate Dun 219. Dun 219, the northerly of the two systems forms an almost perfect equilateral triangle with the primary at the NE vertex. The primary has a Spectral Class of G8III, yellow. I saw a slight yellow tint to the primary, indicating it on the sketch. Stelle Doppie has the Lit. for Dun 219 here. HJ 5000 forms a long scalene triangle with the primary at the southern vertex. The AB pair are orbital and decreasing. The primary is variable with a Spectral Class of A3III, white. Stelle Doppie has the Lit. for HJ 5000 here. I plotted and labeled four field stars to anchor the two objects in the FOV. Sissy Haas in her book, Observing Double Stars for Small Telescopes describes the components of the two systems as, “These pairs are just arcminutes apart. Gould, 175mm, 100X: Dun 219 is very easy…and visible in an 8 X 50 finder…its main star is yellow. H 5000 is an easy, uneven, attractive pair.”
B 2331, HD 124578, WDS 14153-3508 in Centaurus. Slew 2° 08’ almost NE, (55°), from Theta Cen, Menkent, to locate this system. The trio of stars form a long scalene triangle with the primary at the NE vertex. I observed with a Televue Delos 6mm EP at 166X, 0.4° FOV. I labeled three field stars to anchor the object in the FOV. The Spectral Class of the primary is A1, white. Stelle Doppie has the Lit. here.
On June 11, 2021 I made these observations from the Summit with a Burgess 125mm refractor/CGEM on a pier. The conditions were quite good with wind at 14mph, (6m/s), humidity 10% and air temp. 46°. The Jetstream was howling at 25m/s although it didn’t hamper seeing 13th mag. pinpoints.
Algieba, Gam1 Leo, Struve 1424, SAO, WDS 10200+1950 in Leo. This is the brightest of five stars that form the “sickle”. The B component is a close companion to the SE of the primary. The C, D, and E components from an arc to the NW of the pair, roughly 6 arcminutes away. With a Televue Delos 6mm EP at 166X, 0.4° FOV, I plotted only two field stars which I labeled on the sketch. With a TMB 4mm planetary EP at 250X, 0.23° FOV, I show the five stars in the system. The Spectral Class of the primary is KoIII, yellow orange. It glowed well in the refractor and I indicated the color is my sketch. Stelle Doppie has the Lit. here. This system is pretty close to us at about 125 LY and the C component has a tight companion, identified as Bag 32, Ca, Cb. The companion is orbital at 0.006” and decreasing; only observable with spectroscopic equipment. Sissy Haas in her book, Observing Double Stars for Small Telescopes describes the AB components as, “Showcase pair, (Algieba). 60mm, 120X: A brilliant figure 8, slightly unequal, grapefruit orange in color. Smyth: Bright orange; greenish yellow. Webb: Gold, greenish red.”
H4 99 ABCDE, SAO 105321 & 105324, WDS 19500+1757 in Sagitta. Starhop 50’ 49” SE, (132°), from Delta Sge to locate this object in the EP. The A, B and C stars form a nearly straight line East-West with the primary in the center, a little closer to the B component. There is a 13th Mag. D component to the NNW of the primary and an E component off to the SE, further out, that will be a challenge. For some reason with averted vision I was able to get the E component in the Low Power view. The conditions allowed me to snatch the D component in the high power view which turned out to be a surprise! The Spectral Class of the primary is B7Vp, blue-white. Stelle Doppie has the Lit. here.
So, there you have some very interesting systems observed recently from our Haleakala Amateur Astronomers site at the summit of Haleakala. Some are observable as the summer continues. Let me know if you have had an opportunity to observe any of these.
Edited by mauigazer, 18 July 2021 - 01:47 AM.