CD Double Star Measures: Jack Jones Memorial Observatory Report #3

Transcription

1 Page 296 CD Double Star Measures: Jack Jones Memorial Observatory Report #3 James L. Jones Bents Rd NE Aurora, OR Abstract: This paper submits 114 CCD measurements of 92 multiple star systems for inclusion in the WDS. Observations were made during the calendar year Measurements were obtained using either an SBIG ST-7 CCD camera or an SBIG ST-8 CCD camera and an 11-inch SCT. Selected double stars are discussed. Negative findings are included for certain stars. This paper reports on double star observations and measurements made at the Jack Jones Memorial Observatory during Observations were made using a Celestron 11- inch (28 cm) f/10 SCT with a Meade f/6.3 focal reducer/field flattener. This combination yields a pixel scale of approximately 0.95 arcsec/pixel. Prior to an SBIG-ST7 camera with a Kodak KAF- 401E non anti-blooming (NAB) sensor was used for all observations. From onward an SBIG- ST8XME camera with a KAF-1603ME Kodak NAB sensor was used. Multiple images of each target were solved using "Astrometrica". Position Angle and Separation and their associated standard deviations were then computed from the RA and Dec of the primary and secondary using a VB Script written by the author. The UCAC-2 catalog was used in most cases for image solution. Where UCAC-2 was unavailable or didn't provide adequate reference stars, USNO-B1.0 was used. The precision of each observation was quantified and reported by calculating the standard deviation of the image set. More detailed information regarding method can be found in Jones, Results and Discussion Position Angle (θ) and Separation (ρ) measurements are reported in columns θ and ρ respectively in Table 1. The precision of θ and ρ is reported in columns σ(ρ) and σ(θ) and refers to the standard deviation of θ and ρ for the image set. Column N indicates the number of nights that contributed to the measurement. NAME, RA DEC, and MAGS columns are taken from the WDS POU3618 (Theta = 97, Rho = 13.6, mag 12.05, 12.8) lies in a crowded field and was discovered by M. A. Pourteau in It has been observed three times since its discovery, the last observation being in The precise coordinate is listed in the WDS as UCAC 3 places an 11th magnitude star at There are 3 potential companion stars within 50 arcsec of this star. However the brightest is mag 14.6 and is over 25 arcsec away. There is a pair at (author s measurement) that has a separation and PA of 90.4 degrees. This pair corresponds to and (UCAC3). I believe that this is the pair that is being measured as POU3618.

2 Page 297 It should be noted that UCAC3 gives the proper motion for this pair as pmra, pmde and 93.7 pmra, pmde. Consequently, this pair is probably not a physical pair HJ1374AB (Theta = 115, Rho = 14.3, mag 8.9, 12.6) and HJ 1374AC (Theta = 6, Rho = 31.3, mag 8.9, 14.4) were discovered in 1901 and not observed since their discovery. The WDS lists the precise coordinate as While there is a Vmag (TASS) star at that coordinate, there are no companions near the position angles given. The author believes that the primary component of this system is a Vmag (TASS) star situated approximately 4 minutes to the east at UCAC3 coordinates , with the companions at (Theta = 119, Rho = 13.34) and (Theta = 2.5, Rho = 30.26) SLE 630AC (Theta = 96, Rho = 14.8, mag 10.3, 11.6) was discovered by G. Soulie in 1984 and has not been observed since. The author measured this pair as Theta = 59.6, Rho = An image of the SLE 630 system is shown in Figure 1. Even a cursory examination of this image will confirm that the C component is much closer to 60 degrees than 96 degrees. Could the numbers for Theta have been transposed? There is an Vmag (TASS) star at those coordinates. However, there are no stars near 11 magnitude within 1.7 minutes of this star. There is a 13 mag pair about 3 minutes to the NW with close to the proper orientation but they are 2 magnitudes too dim and twice the separation POU3259 (Theta = 035, Rho = 15.7, mag 9.9, 12.8) was discovered by M. A. Pourteau in 1902 and not observed since. The WDS lists the precise coordinate as A search of Tycho (i/259/tyc2) within 60 arcmin of the precise coordinate only yielded one possibility 40 min NE at and (Theta = 11.1, Rho=19.39, Vt = 9.557, ). USNOB1.0 proper motions of this pair are pmra = 16mas/yr and pmde = -14mas/yr for the primary and zero for the secondary. So there is no reason to conclude that this is the lost double CHE 430 (Theta = 285, Rho = 13.8, mag 10.19, 11.01) was discovered by P.S. Chevalier in 1910 and not observed since. The WDS lists the precise coordinate as There is an 11 magnitude star located at (UCAC3). However there are no stars bright enough to be a potential companion. Examination of DSS and UMASS imagery didn t yield any potential candidates. Acknowledgements This research made use of the Washington Double Star Catalog maintained at the U.S. Naval Observatory and the VizieR catalogue access tool, CDS, Strasbourg, France. References Jones, James L., 2008, "CCD Double Star Measures: Jack Jones Memorial Observatory Report #1",, 4, Figure 1: SLE 630AB and SLE 630 AC. North up. East left Negative Findings POU3264 (Theta = 299, Rho = 15.8, mag 11.58, 11.9) was discovered by M. A. Pourteau in The WDS lists the precise coordinate as

3 Page 298 HJ ALI AG 311AB CTT 8AC POU POU POU POU POU POU POU HJ LDS HJ KZA 5AB KZA 5AC KZA 44AB KZA 44AC KZA KZA KZA 71AB KZA 71AC POU HJ HJ 238AB HJ 238AC ABH 82AD HJ 2776AB KZA STF KZA KZA GIC 127AB LMP 10AC LMP 10AD KZA 92AB KZA 92AC KZA KZA 100AB TOB 133AC Table continues on next page.

4 Page 299 STF1961AB STF1961AC FOX 190AC KZA 105AB KZA 105AC KZA 105AD KZA 105AE KZA 105AF KU POU POU POU POU POU POU POU SLE FOX HJ POU POU3595AB POU3594AC HJ POU POU HJ POU GYL 12AB BKO 56AC POU POU POU ARG 83AB ARG 83AC HJ 1374AB HJ 1374AC SMA SLE 630AB SLE 630AC SLE Table continues on next page.

5 Page 300 LDS SLE 669AB ES 2681AB ES 2674AC HJ 1441AC SMA SMA SMA SMA SMA HJ 1472AB CTT 9AC CHE ES SEI SEI SEI SEI SEI SEI SEI SEI SEI CHE CHE CHE CHE CHE 381AB CHE CHE CHE CHE CHE CHE Notes: 1. Apparently in NGC Apparently in NGC Apparently in NGC See Discussion