TABLE 1- Absolute photometry of HRX-BL Lacs in the B band

Object name

Date

Julian Date (2451000.0+)

B mag

Err

Exp(s)

alphaOX

alphaRO

1RXS J085916.5+834450

2000/05/04

669.3484

19.73

0.19

600

0.84

0.39

B2 0906+31

2000/05/02

667.3408

18.28

0.07

240

0.97

0.52

1RXS J091324.6+813318

2000/05/02

667.3582

20.7

0.10

600

0.59

0.40

1RXS J091651.8+523829

2000/05/02

667.3471

18.33

0.05

600

0.97

0.50

1RXS J092401.1+053350

2000/05/04

669.3724

19.60

0.09

500

0.82

0.36

1RXS J092804.2+744714

2000/05/02

667.3694

20.7

0.10

800

0.72

0.62

1RXS J095225.8+750216

2000/05/04

669.3713

19.20

0.19

500

0.85

0.37

1RXS J095929.8+212340

2000/05/04

669.3817

19.06

0.06

400

0.81

0.45

1RXS J100811.5+470526

2000/05/04

669.3959

19.92

0.10

400

0.58

0.34

1RXS J101244.4+422959

2000/05/04

669.3890

18.42

0.05

300

0.85

0.45

1RXS J101616.4+410817

2000/05/04

669.4036

19.46

0.05

200

0.76

0.40

1RXS J105125.1+394329

2000/04/28

665.3856

19.0

0.18

800

0.87

0.34

1RXS J105607.0+025215

2000/05/02

667.3871

19.39

0.05

900

0.64

0.30

1RXS J105723.5+230317

2000/04/28

663.3798

19.74

0.05

600

0.73

0.37

1RXS J110021.3+401933

2000/05/02

667.4236

18.56

0.05

300

0.90

0.35

1RXS J110748.2+150217

2000/05/02

667.4153

18.4

0.20

400

0.94

0.41

1RXS J111131.2+345212

2000/05/02

667.4031

19.7

0.05

800

0.70

0.38

1ES 1118+424

2000/05/02

667.4313

18.0

0.20

200

0.89

0.34

1RXS J114930.4+243928

2000/05/02

667.4403

19.0

0.20

400

0.82

0.42

1RXS J121158.1+224236

2000/04/28

663.4011

19.55

0.05

500

0.71

0.43

1RXS J123014.2+251805

2000/05/02

667.4591

15.94

0.05

150

1.41

0.38

MS 1229.2+6430

2000/05/02

667.4515

18.0

0.20

300

1.03

0.41

MS 1235.4+6315

2000/04/28

663.4359

18.85

0.05

600

0.94

0.35

1RXS J123923.1+413245

2000/04/28

663.4240

20.34

0.10

600

0.75

0.43

1RXS J124141.2+344032

2000/04/28

663.4466

20.18

0.16

600

0.79

0.42

1RXS J124312.5+362743

2000/05/02

667.4660

16.60

0.10

300

1.08

0.38

1RXS J124818.9+582031

2000/05/02

667.4749

14.89

0.05

200

1.52

0.29

1RXS J125301.0+382629

2000/04/28

663.4631

18.9

0.20

500

0.76

0.27

1RXS J130255.6+505621

2000/04/28

663.4761

19.3

0.20

600

0.75

0.26

1RXS J132400.2+573918

2000/05/03

667.4944

17.75

0.05

200

1.17

0.37

1RXS J132615.0+293332

2000/04/28

663.4868

18.69

0.05

500

0.95

0.27

1RXS J134029.9+441007

2000/04/28

663.4965

19.25

0.11

400

0.83

0.48

1RXS J134104.8+395942

2000/05/03

667.4868

18.6

0.22

400

0.83

0.48

1RXS J135328.2+560102

2000/05/02

667.5000

19.10

0.05

600

0.92

0.37

1RXS J140450.2+655433

2000/04/28

663.5053

19.36

0.08

600

0.90

0.40

1RXS J141031.6+610020

2000/05/02

667.5774

19.89

0.07

1200

0.79

0.41

1RXS J142239.1+580159

2000/04/29

663.5169

17.82

0.07

400

0.76

0.27

MS 1443.5+6349

2000/04/29

663.5600

19.7

0.20

600

0.87

0.44

1RXS J144932.3+274630

2000/05/02

667.5362

20.03

0.10

600

0.63

0.58

1RXS J145603.4+504824

2000/04/29

663.5506

18.57

0.07

400

0.68

0.23

1RXS J145827.3+483250

2000/05/02

667.5146

20.37

0.09

1200

0.60

0.34

1RXS J150101.7+223812

2000/05/03

667.6018

15.53

0.05

180

1.39

0.19

1RXS J150842.2+270910

2000/04/29

663.5842

18.77

0.05

600

0.84

0.43

1RXS J151040.8+333515

2000/04/29

663.6097

18.50

0.07

500

0.98

0.30

1517+656

2000/04/29

663.5756

16.87

0.04

150

0.94

0.28

1ES 1533+5320

2000/04/29

663.6192

18.9

0.20

400

0.63

0.37

1ES 1544+820

2000/04/29

663.6287

17.1

0.18

300

1.03

0.35

1RXS J155411.8+241415

2000/04/29

663.6413

20.4

0.20

300

0.93

0.46

MS 1552.1+2020

2000/04/29

663.6021

18.45

0.05

300

0.78

0.45