S-Type stars


S-type stars are cool giants which show evidence of bands of ZrO in their spectra (4641A, 4620A, 5304A, 5379A, 5551A). The TiO bands are also visibles and some time, strong hydrogen emission lines due to shock waves in pulsating atmosphere. This stars are often variables of many type. The Mira-type is the major population.

A list of bright S stars:

     HD        Name        R.A.         Dec.     Mv     Spec.

224960      W Cet    00 02 07.4   -14 40 30   7.1   S5-7/1.5-3e
  4350      U Cas    00 46 21.4   +48 14 42   8.0   S5/3e
  4489     RW And    00 47 18.9   +32 41 19   7.9   S6/2e
  4895     RR And    00 51 23.5   +34 22 39   8.4   S6/3e
  5840   V365 Cas    01 00 53.1   +56 36 46   8.0   S6/3
  7351               01 14 04.4   +28 31 48   6.6   S3/2
  7769      S Cas    01 19 42.1   +72 36 41   7.9   S4,6e
 14028      W And    02 17 33.0   +44 18 20   6.7   S7/1e
 22649     BD Cam    03 42 09.4   +63 13 25   5.1  S4/2
 29147      T Cam    04 40 08.8   +66 08 48   7.3   S6/5e
 29704               04 39 23.6   -30 27 13   8.5   S:
 30959  Omi 1 Ori    04 52 31.5   +14 15 05   5.2   S3/1
           RZ Lep    05 18 46.0   -22 12 39   8.3   S4/4
 35155  V1261 Ori    05 22 18.4   -08 40 04   7.0   S4,1
 37536     NO Aur    05 40 41.9   +31 55 17   6.7   M2S
 40101               05 55 35.4   -28 57 04   7.8   S
 49368               06 48 22.8   +05 32 35   8.5   S3/2
 51610      R Lyn    07 01 17.9   +55 20 02   7.2   S5/5e
 53791      R Gem    07 07 21.1   +22 42 17   6.0   S5/5
 56567     RR Mon    07 17 32.0   +01 05 40   8.4   M7Se:
 61913               07 42 03.4   +14 12 59   5.8   M3S
 63334      T Gem    07 49 18.2   +23 44 02   8.0   S4/4e
 63733               07 49 45.8   -19 00 21   8.5   S4/3
 64332     NQ Pup    07 53 05.3   -11 37 31   7.6   S5/2
 70276      V Cnc    08 21 42.8   +17 17 03   7.5   S3/6e
 96360               11 07 52.5   +68 21 59   8.4   M3
 97393     BI Hya    11 12 13.1   -32 25 37   6.5   S
110813       U Ma    12 43 56.2   +61 05 35   7.4   S3/6e
127226      R Cam    14 17 50.9   +83 49 57   7.9   S4/4e
           RT Sco    17 03 31.2   -36 55 14   7.0   S7,2
170970   V463 Lyr    18 30 36.3   +36 15 12   7.6   S3/1
176592     ST Sgr    19 01 28.9   -12 45 32   7.6   S6/3e
            W Aql    19 15 23.7   -07 02 55   7.8   S6/6e
180196      T Sgr    19 16 14.4   -16 58 11   7.7   S5/6e
185456      R Cyg    19 36 49.1   +50 11 59   6.5   S6/6e
187796    Chi Cyg    19 50 33.8   +32 54 51   3.3   S7/1.5e
188339               19 56 10.9  -38 19 12    6.6   S
191226               20 07 25.2  +36 34 24    7.4   M1S-M3SIIIa
191589               20 09 28.2  +33 40 39    7.7   S:
195763      Z Del    20 32 39.1  +17 27 06    8.3   S4/2e
           FF Cyg    20 38 52.4  +37 53 20    8.2   S5/6e
199799               20 57 53.1  +44 47 20    8.0   MS
211610      X Aqr    22 18 39.1  -20 54 04    7.5   S6,3e:
216672     HR Peg    22 54 35.3  +16 56 39    6.5   S4/1
218634     57 Peg   23 09 31.9   +08 40 31    5.4   M4S


The spectral data were reduced in the standard manner using Iris and VisualSpec. The instrumental response function was removed from target spectra by using standard star spectra. The relative flux is normalized at the wavelength 6630 angstroms. 


HR Peg