NGC 2808 C0911-646 (Updated June 2011) RA: 09:12:03.10 DEC: -64:51:48.6 (J2000) ============================================================ Bytes Format Explanation 1-8 A8 Star ID 10-32 A11,1x,A11 Position 34-35 A2 Units for position R0 denotes RA, DEC in the J2000 coordinates R5 denotes RA, DEC in the 1950 coordinates XA denotes X, Y in arcseconds XP denotes X, Y in pixels 37-44 F8.4 Period (days) 46-51 F6.3 Mean magnitude (or maximum magnitude if "max" is indicated in the remarks column) 53-57 F5.3 Light amplitude (range of variability) 59 A1 Colour for mean magnitude and amplitude e.g. B, V, R, I, J, K or P (for photographic). 61-65 A5 Type of variable (draft 2006 GCVS classifications) CST denotes non variable stars previously designated as variables 67-80 A19 Notes and Remarks (f denotes field star) "--" or "----" indicates no data available ========================================================================= ID Position Period ampl C Type Notes/ RA/X Dec/Y Units Remarks ========================================================================= 1 09:12:20.21 -64:52:20.5 R0 119.0 13.53 1.4 V SR 2 09:11:55.66 -64:51:10.4 R0 ---- -- -- CST Note 3 09:12:08.38 -64:52:47.2 R0 ---- -- -- CST 4 09:11:33.75 -64:50:44.0 R0 ---- -- -- CST Note 5 09:12:09.58 -64:52:52.6 R0 ---- -- -- CST 6 09:12:30.08 -64:56:37.9 R0 0.5390 16.27 0.80 V RR0 K11 7 09:12:13.13 -64:50:46.4 R0 ---- -- -- CST 8 09:12:06.56 -64:53:49.3 R0 ---- -- -- CST 9 09:11:53.06 -64:54:24.3 R0 ---- -- -- CST 10 09:11:56.85 -64:53:23.1 R0 1.7653 15.56 1.00 B CW 11 09:12:06.73 -64:52:40.3 R0 111.0 13.25 1.6 V SR 12 09:11:55.63 -64:50:09.5 R0 0.3058 16.30 0.45 B RR1 13 09:12:23.37 -64:57:10.8 R0 0.21 -- -- RR1? Note 14 09:12:13.46 -64:51:04.3 R0 0.5989 16.25 0.78 V RR0 K11 15 09:12:10.67 -64:51:16.0 R0 0.6109 16.30 0.40 RR0 K11 16 09:12:09.16 -64:52:51.8 R0 0.6052 16.23 0.77 RR0 K11 17 09:12:07.08 -64:51:57.3 R0 0.38 -- -- RR1 18 09:12:06.65 -64:52:17.4 R0 0.5562 16.00 0.50 RR0 K11 19 09:12:06.30 -64:52:10.9 R0 0.51 -- -- RR0 20 09:12:05.58 -64:51:31.2 R0 0.29 -- -- RR1 21 09:12:03.95 -64:51:26.1 R0 0.60 -- -- RR0 22 09:12:03.92 -64:51:55.8 R0 0.54 -- -- RR0 Note 23 09:12:03.32 -64:52:20.2 R0 0.27 -- -- RR1 24 09:12:02.73 -64:52:11.3 R0 0.27 -- -- RR1 25 09:11:58.72 -64:51:28.5 R0 0.5156 16.43 0.81 RR0 K11 26 09:11:53.13 -64:51:31.1 R0 0.37 -- -- RR1 27 09:11:53.68 -64:52:59.9 R0 0.57 -- -- RR0 28 09:11:50.62 -64:51:28.2 R0 0.28 -- -- RR1 29 09:12:00.58 -64:51:39.5 R0 1.97 -- -- CW? 30 09:11:49.37 -64:51:52.8 R0 1.47 -- -- EC 31 09:11:57.1 -64:51:29.7 R0 60.0 13.40 0.5 SR 32 09:11:58.7 -64:51:28.5 R0 34.0 13.77 0.1 SR 33 09:11:59.2 -64:52:59.2 R0 200.0 13.50 0.5 SR altP=42 34 09:12:01.4 -64:51:37.4 R0 72.0 13.65 0.6 SR 35 09:12:01.7 -64:50:33.2 R0 359.0 13.59 0.5 SR altP=49 36 09:12:02.3 -64:51:18.4 R0 33.0 13.49 0.1 SR 37 09:12:02.7 -64:52:01.7 R0 21.0 13.69 0.1 SR 38 09:12:04.3 -64:51:41.7 R0 375.0 13.68 0.8 SR 39 09:12:06.7 -64:52:18.1 R0 36.0 13.54 0.2 SR 40 09:12:08.5 -64:51:58.4 R0 50.0 13.62 0.1 SR 41 09:12:11.3 -64:52:42.2 R0 89.0 13.52 0.4 SR 42 09:12:14.5 -64:53:26.7 R0 42.0 13.34 0.2 SR 43 09:12:16.6 -64:52:02.8 R0 383.0 13.46 0.2 SR 44 09:12:18.5 -64:51:30.6 R0 26.0 13.60 0.1 SR 45 09:12:03.9 -64:51:54.2 R0 332.0 13.89 0.8 SR 46 09:11:50.3 -64:51:42.2 R0 ---- 13.82 -- L 47 09:12:01.5 -64:50:49.3 R0 ---- 13.85 -- L 48 09:12:04.9 -64:51:29.7 R0 ---- 14.28 -- L 49 09:12:05.9 -64:52:08.1 R0 ---- 13.58 -- L 50 09:12:24.8 -64:51:10.3 R0 ---- 13.44 -- L ============================================================== Supplementary Notes V1-12: The RA and Dec are from Samus et al. (2009) and are updated from an earlier paper by Evstigneeva et al. (1997). Most of the remaining information for these stars (except V1, V6 and V11) is from Clement & Hazen (1989). Lebzelter & Wood (2011) derived periods and magnitudes for V1 and V11 as part of their study of long period variables and Kunder et al. (2011) derived a period, magnitude and amplitude for V6 in their investigation of RR Lyrae variables. V13-30: The periods and classifications for most of these variables are from a paper by Corwin et al. (2004). [For the stars indicated by K11 in the comments column, the data were derived by Kunder et al. (2011).] Corwin et al. (2004) did not derive magnitudes or amplitudes because they used the image subtraction method. The RA and dec listed for V13-V30 in the above table were provided independently by Corwin (2010, private communication) because there were errors in the coordinates they published in Table 1 on page 669 of their 2004 paper. V31-50: The RA, dec, periods and mean magnitudes are from Lebzelter & Wood (2011) who designated them as LW1-20. The amplitudes listed for these stars have been estimated to the nearest 0.1 mag from their published light curves. =============================== Notes on individual stars V2, V4: Evstigneeva et al. (1997) noted that there was a faint component near V2 and that V4 was clearly separated into two components. This may account for the apparent variation of these stars on the discovery plates of Fourcade et al. (1966). Both stars were considered to be non-variable by Clement & Hazen (1989). V13: The classification of this star is uncertain. Corwin et al. (2004) tentatively classified it as RR1, but indicated that it might be RR2 or EC. V22: This variable was confirmed by Dieball et al. (2005). It was their star #358 and they published RA (9:12:3.858) and Dec (-64:51:55.847). ================================================================== Discovery of the variable stars in NGC 2808: V1-7 Fourcade et al. (1966) with x,y coordinates and an ID chart V8-9 = stars 27 and 35 of Alcaino (1971 - see page 366) with an ID chart on page 364. The direction north (N) is incorrectly labelled on Alcaino's chart. North is on the right side not at the top as he states. East is at the top. The numbers V8 and V9 were assigned by Sawyer Hogg (1973) in her 3rd catalog. V10-12 Clement & Hazen (1989, AJ 97, 414) with x,y positions and an ID chart which includes V1 and V6 as well. V13-30 Corwin et al. (2004) with RA, dec and an ID chart V1, V6, V10, and V12 are also labelled on their chart. V31-50 = LW1-20 Lebzelter & Wood (2011) with RA and dec The numbers V31-50 have been assigned in this catalogue. ----------------------------------------------- Additional investigations of variables Dieball et al. (2005) identified 6 variable stars from HST FUV observations. They published RA, dec and an ID chart for all of them: #358 - an RR Lyrae on the ZAHB which they believed to be Corwin's V22 #76, #124, #162 - blue stragglers near the main sequence, #124 a probable binary and the other two probably pulsating variables #222, #397 - possible CVs, between the WD and MS regions Servillat et al. (2008) studied X-ray data from Chandra and XMM-Newton and Hubble FUV data and found one neutron star quiescent low mass X-ray binary and 8 CV candidates. The qLMXB candidate (Chandra source #1 in their paper) has 2000 position RA 9:12:01.91, dec -64:51:50.67. They also stated that one of their CV candidates, Chandra source #7, is the same object as Dieball #222. ----------------------------------------------------------------- Pietrukowicz et al. (2008) searched for dwarf novae in NGC 2808 based on observations made during 33 nights in 1998 and 1999. No outbursts were detected. ======================================================================== References Alcaino. G. 1971, A&A 15, 360 Clement, C. M. & Hazen, M. L. 1989, AJ, 97, 414 Corwin, T. M., Catelan, M., Borissova, J., Smith, H. A. 2004, A&A, 421, 667 Dieball, A., Knigge, C., Zurek, D. R., Shara, M. M., Long, K. S. 2005, ApJ, 625, 156 Evstigneeva, N. M., Samus, N. N., Alcaino, G. 1997, Ast Let 23, 395 (translated from Pis Ast Zh 23, 454). Fourcade, C. R., Laborde, J. R., Albarracin, J. 1966, Atlas y Catalogo de Estrellas Variables en Cumulos Globulares al sur de -29 degrees, Cordoba Kunder, A., Stetson, P., Catelan, M., Amigo, P., de Propis, R. 2011, in Carnegie OBs. Astrophys. Series, Vol. 5: RR Lyrae, Metal-Poor Stars, and the Galaxy, ed. A. McWilliam = 2011, arXiv1105.0008v1 Lebzelter, T. & Wood, R. 2011, A&A, 529, A137 Pietrukowicz, P., Kaluzny, J., Schwarzenberg-Czerny, A., Thompson, I. B., Pych, W., Krzeminski, W., Mazur, B. 2008, MNRAS, 388, 1111 Samus, N. N., Kazarovets, E. V., Pastukhova, E. N., Tsvetkova, T. M., Durlevich, O. V. 2009, PASP, 121, 1378 Servillat, M., Dieball, A., Webb, N. A., Knigge, C., Cornelisse, R., Barret, D., Long, K. S., Shara, M. M., Zurek, D. R. 2008, A&A, 490, 641 ============================================================================