from ucac to urat

from UCAC to URATYale, 2008 Sep 20 1

From UCAC to URAT

Norbert Zacharias

U.S. Naval ObservatoryAstrometry Department

Cataloging Division

nz@usno.navy.mil

from UCAC to URATYale, 2008 Sep 20 2

acknowledgement UCAC (CCD setup, survey):

T.Rafferty, M. Germain, J.Pohlman, ...

all observers & site support (O.Saa, D.Castillo ... T.Tilleman)

M.Zacharias, C.Finch, G.Wycoff, ....

UCAC (proper motions): S.Urban, W. van Altena, T.Girard, A.Klemola, D.Monet, ...

U-mouse (detector): STA (R.Bredthauer, ...), G.Luppino ...

U-mouse (astrograph): USNO instrument shop (G.Wieder, ...)

USNO management (R.Gaume, K.Johnston ...)

from UCAC to URATYale, 2008 Sep 20 3

U S N OC C DA s t r o g r a p hC a t a l o g

“red lens” astrograph + 4k CCD

combined with

early epoch photographic data

from UCAC to URATYale, 2008 Sep 20 4

UCAC observing

1997 – 2004 (all-sky completed) 579 – 642 nm bandpass R = 8 to 16 mag positions accurate to 20 mas (10 – 14 mag) incl. proper motions (various early catalogs)

thanks Bill ! SPM = major contributor

most accurate astrometry for fainter than Hip.

from UCAC to URATYale, 2008 Sep 20 5

modify dome at CTIO

from UCAC to URATYale, 2008 Sep 20 6

observing at CTIO

from UCAC to URATYale, 2008 Sep 20 7

backend of astrograph

4k camera

x-y slide

from UCAC to URATYale, 2008 Sep 20 8

UCAC products

UCAC1 (2000) : part of Southern Hemisphere UCAC2 (2003) : -90 to +50 deg decl. UCAC3 (2009) :

all-sky coverage; re-processing all pixel data

much improved completeness (bright stars, doubles)

improved astrometry (empirical profile fits, global iterations)

improved proper motions bright: new data: AGK2

improved proper motions faint: re-reduct. NPM, SPM

improved photometry (1 band)

from UCAC to URATYale, 2008 Sep 20 9

re-processing pixel data

4.5 TB compressed dark, flat handling double star fits empirical profiles identify overexposed multi-level results, flags keep “fit crash”

from UCAC to URATYale, 2008 Sep 20 10

from UCAC to URATYale, 2008 Sep 20 11

from UCAC to URATYale, 2008 Sep 20 12

StarScan plate measuring

early epoch data for proper motions, bright stars

CCD camera, step-stare mode accurate to <= 0.5 micrometer absolute

Zacharias et al. 2008, PASP

1930 AGK2: 1,900 plates 1976..1995 ZA: 2,300 plates 1983..1990 BB: 900 plates

from UCAC to URATYale, 2008 Sep 20 13

StarScan plate measure machine

Washington, DC

from UCAC to URATYale, 2008 Sep 20 14

SPM astrograph in Argentina

from UCAC to URATYale, 2008 Sep 20 15

from UCAC to URATYale, 2008 Sep 20 16

KPNO 2.1 m

extragalactic reference frame link

from UCAC to URATYale, 2008 Sep 20 17

from UCAC to URATYale, 2008 Sep 20 18

UCAC3 public release status

reductions completed: pixel re-processing --> x,y data, various models

“plate adjustment”, systematic errors (model, FDP, CTE)

StarScan data up to RA, Dec; SPM: final model decisions

levels of products, options for release:1) mean position catalog (80 million stars, all sky) include only if >=

2 detections + PM available

2) extract and identify minor planets -> separate catalog

3) identify double stars -> flags in main catalog

4) individual epoch RA, Dec of all detections

5) pixel data images (very noisy, dark current ...)

from UCAC to URATYale, 2008 Sep 20 19

U S N OR o b o t i cA s t r o m e t r i cT e l e s c o p e

4-shooter camera

plus

new 0.85m telescope

from UCAC to URATYale, 2008 Sep 20 20

URAT overview

USNO Robotic Astrometric Telescope

0.85 m aperture, focal length = 3.6 m 4.5 degree diameter field of view large format detector (world largest CCD)

2 px / FWHM at 1.0 arcsec seeing 9 micrometer pixel size 4 CCDs, each 95 mm on a side

60 s / 240 s integration 13 to 21 mag goal 5 mas for 'well exposed stars'

from UCAC to URATYale, 2008 Sep 20 21

URAT optical design

from UCAC to URATYale, 2008 Sep 20 22

URAT cut side view

EOST, 2005

from UCAC to URATYale, 2008 Sep 20 23

URATFASA2(EOST 2005)

from UCAC to URATYale, 2008 Sep 20 24

0.9 m primary mirror delivered, Feb.08

from UCAC to URATYale, 2008 Sep 20 25

status of URAT project

telescope: optical design studies completed primary mirror: delivered Feb. 2008 no funding to complete new telescope

detector: 10.5k by 10.5k CCD chip produced successfully thinning of 2 science grade chips May/July 2007 10k camera complete, 1st light October 2007 4-shooter camera funded, delivery March 2009

from UCAC to URATYale, 2008 Sep 20 26

“U-mouse”

(if you can't get the “rat”,how about a “mouse”?)

from UCAC to URATYale, 2008 Sep 20 27

from UCAC to URATYale, 2008 Sep 20 28

10k camera dewar

from UCAC to URATYale, 2008 Sep 20 29

astrographwith 10k camera

from UCAC to URATYale, 2008 Sep 20 30

URAT phase 1 = U-mouse

currently no funding for new telescope

take 4-shooter camera, put at astrograph

complete re-make of astrograph 2007/08

move to CTIO or NOFS, begin new survey 2009

28 sq. deg. per exposure!

11 mas per image coord. (well exposed star)

multiple sky overlaps per year, 7 - 18 mag

clocked anti-blooming: seems to work!

solve for positions, motions + parallax

from UCAC to URATYale, 2008 Sep 20 31

STA1600B 4-shooter camera headconcept – front view

• Cryostat window –

350mm diameter,

300mm clear

aperture.

from UCAC to URATYale, 2008 Sep 20 32

4-shooter camera dewar

assembly

G.Luppino

from UCAC to URATYale, 2008 Sep 20 33

U-mouse project numbers

sky area per hemisphere 25,000 sq.deg field size per exposure 25 sq.deg number of fields 1000 2 exposures / field / epoch 60, 240 sec time for 1 field (exp.pair) 6 min time for 1-fold sky overlap 100 hour avail. observ. time / year 2,200 hour (CTIO) ...dark time, good seeing 1,500 hour (CTIO) numb. sky overlaps in 2 years 30 at CTIO numb. sky overlaps in 2 years 15 at NOFS single measure precision 11 mas(cent.+atm)...for well exposed stars R= 11..15; 40 mas R=17end of operation random error 2 mas at CTIO end of operation random error 3 mas at NOFS

systematic errors < 10 mas --> ???

from UCAC to URATYale, 2008 Sep 20 34

rebuilding astrograph in 24in dome

from UCAC to URATYale, 2008 Sep 20 35

astrograph new tube assembly

from UCAC to URATYale, 2008 Sep 20 36

USNO instrument shop Sep 2008astrograph tube assembly

from UCAC to URATYale, 2008 Sep 20 37

fully funct. 10k chip

image16

outputs

STA2008

Sep 17

from UCAC to URATYale, 2008 Sep 20 38

summary

UCAC3: all-sky to 16th mag, catalog in 2009 URAT -> Umouse: first light 2009

111 million pixel CCD detector on sky tested in 2007 use re-furbished astrograph for phase 1, 2008 get 4-shooter camera by March 2009 observe 2-3 years per site (NOFS, CTIO) catalog of positions, proper motions, parallaxes 2012

?