TABLE 1

Observed Astrometric Positions for the Haumea System

Julian Date

Date

Telescope

Camera

xH
(arcsec)

yH
(arcsec)

σxH
(arcsec)

σyH
(arcsec)

xN

yN

σxN

σyN

2453397.162

2005 Jan 26

Keck

NIRC2

0.03506

-0.63055

0.01394

0.01394

2453431.009

2005 Mar 1

Keck

NIRC2

0.29390

-1.00626

0.02291

0.02291

0.00992

0.52801

0.02986

0.02986

2453433.984

2005 Mar 4

Keck

NIRC2

0.33974

-1.26530

0.01992

0.01992

2453518.816

2005 May 28

Keck

NIRC2

-0.06226

0.60575

0.00996

0.00996

2453551.810

2005 Jun 30

Keck

NIRC2

-0.19727

0.52106

0.00498

0.00996

-0.03988

-0.65739

0.03978

0.03978

2453746.525

2006 Jan 11

HST

ACS/HRC

-0.20637

0.30013

0.00256

0.00256

0.04134

-0.18746

0.00267

0.00267

2453746.554

2006 Jan 11

HST

ACS/HRC

-0.20832

0.30582

0.00257

0.00257

0.03867

-0.19174

0.00267

0.00267

2454138.287

2007 Feb 6

HST

WFPC2

-0.21088

0.22019

0.00252

0.00197

-0.02627

-0.57004

0.00702

0.00351

2454138.304

2007 Feb 6

HST

WFPC2

-0.21132

0.22145

0.00095

0.00204

-0.03107

-0.56624

0.00210

0.00782

2454138.351

2007 Feb 6

HST

WFPC2

-0.21515

0.23185

0.00301

0.00206

-0.03009

-0.55811

0.00527

0.00564

2454138.368

2007 Feb 6

HST

WFPC2

-0.21402

0.23314

0.00192

0.00230

-0.03133

-0.56000

0.00482

0.00663

2454138.418

2007 Feb 6

HST

WFPC2

-0.21705

0.24202

0.00103

0.00282

-0.03134

-0.54559

0.00385

0.00376

2454138.435

2007 Feb 6

HST

WFPC2

-0.21449

0.24450

0.00323

0.00254

-0.02791

-0.54794

0.00571

0.00524

2454138.484

2007 Feb 6

HST

WFPC2

-0.21818

0.25301

0.00153

0.00224

-0.02972

-0.53385

0.00797

0.01330

2454138.501

2007 Feb 7

HST

WFPC2

-0.21807

0.25639

0.00310

0.00291

-0.03226

-0.53727

0.00531

0.00400

2454138.551

2007 Feb 7

HST

WFPC2

-0.22173

0.26308

0.00146

0.00230

-0.03429

-0.53079

0.00497

0.00582

2454138.567

2007 Feb 7

HST

WFPC2

-0.21978

0.26791

0.00202

0.00226

-0.03576

-0.52712

0.00270

0.00479

2454469.653

2008 Jan 4

HST

WFPC2

0.23786

-1.27383

0.00404

0.00824

-0.02399

-0.28555

0.00670

0.00831

2454552.897

2008 Mar 27

Keck

NIRC2

0.19974

-0.10941

0.00930

0.00956

2454556.929

2008 Mar 31

Keck

NIRC2

0.32988

-0.77111

0.00455

0.00557

0.00439

-0.76848

0.01239

0.01280

2454556.948

2008 Mar 31

Keck

NIRC2

0.33367

-0.77427

0.00890

0.00753

0.01363

-0.76500

0.01976

0.01252

2454556.964

2008 Mar 31

Keck

NIRC2

0.33267

-0.77874

0.00676

0.00485

0.00576

-0.77375

0.01212

0.01283

2454557.004

2008 Mar 31

Keck

NIRC2

0.33543

-0.78372

0.00404

0.00592

0.00854

-0.77313

0.01199

0.00897

2454557.020

2008 Mar 31

Keck

NIRC2

0.33491

-0.78368

0.00374

0.00473

0.00075

-0.76974

0.00907

0.01015

2454557.039

2008 Mar 31

Keck

NIRC2

0.33712

-0.78464

0.00740

0.00936

0.00988

-0.77084

0.01793

0.01543

2454557.058

2008 Mar 31

Keck

NIRC2

0.33549

-0.78692

0.00868

0.00852

0.01533

-0.76117

0.00765

0.01571

2454557.074

2008 Mar 31

Keck

NIRC2

0.33128

-0.78867

0.01431

0.01411

0.00645

-0.76297

0.01639

0.01390

2454557.091

2008 Mar 31

Keck

NIRC2

0.33687

-0.79462

0.00803

0.00717

0.00708

-0.76986

0.01532

0.00787

2454593.726

2008 May 7

HST

NICMOS

-0.18297

1.08994

0.00354

0.00425

0.00243

-0.75878

0.00576

0.00761

2454600.192

2008 May 13

HST

WFPC2

0.10847

0.17074

0.00508

0.00427

-0.02325

0.19934

0.00480

0.01161

2454601.990

2008 May 15

HST

WFPC2

0.18374

-0.13041

0.00729

0.00504

-0.02293

0.50217

0.00618

0.00614

2454603.788

2008 May 17

HST

WFPC2

0.24918

-0.43962

0.00207

0.00574

-0.01174

0.59613

0.00366

0.00485

2454605.788

2008 May 19

HST

WFPC2

0.29818

-0.75412

0.00467

0.00966

0.00006

0.29915

0.00425

0.00613

Note. Summary of observations of the astrometric positions of Hiiaka (H) and Namaka (N) relative to Haumea. The difference in brightness (6) and orbital planes allow for a unique identification of each satellite without possibility of confusion. The method for obtaining the astrometric  positions and errors is described in Section 2 and Brown et al. (2005). On a few dates, the fainter Namaka was not detected because the observations were not of sufficiently deep or Namaka was located within the PSF of Haumea. This data is shown graphically in Figure 2 and the residuals to the fit shown in Figure 3. For reasons described in the text, only the HST data is used to calculate the orbital parameters, which are shown in Table 2.