The Hubble Space Telescope (HST): one

user’s view

Chris Sneden

Speaking for my friends & colleagues:

John Cowan (Oklahoma), Jim Truran (Chicago), Tim Beers (Michigan State), Francesca Primas (ESO)

Pictures of HST

Very connected with the fate of the shuttle!

HST: a thumbnail history?

HST has been a spectacular success!

Recent (alas!) HST history

Late last week

Yester-day

Back to my comfort zone: using HST while it still lives

What can stellar astronomers learn from cool HST images?

Halo stars are at the outposts of our Milky Way and other galaxies

You are here

(sort of)!

My goal: to use the chemical compositions of stars to help explain the creation of all the

elements in the Periodic Table

Rb Sr Y Zr Nb Mo Tc Ru Rh Pd Ag Cd In Sn Sb Te I

ScCaK

Xe

Ti V Cr Mn Fe Co Ni Cu Zn Ga Ge As Se Br Kr

H

BeLi

MgNa

Hf Ta W Re Os Ir Pt Au Hg Tl Pb Bi Po At Rn

RaFr

BaCs

Rf Db Sg Bh Hs Mt Uun Uuu Uub

CB O F Ne

ArAl Si P S Cl

N

He

La Ce Pr Nd Pm Sm Eu Gd Tb Dy Ho Er Tm Yb Lu

Ac Th Pa U Np Pu Am Cm Bk Cf Es Fm Md No Lr

Atomic Numbers1

3

11

19

37

55

87

57

89

2

10

18

36

54

86

71

103

Remember: Periodic Table elements are created in stellar nucleosynthesis

Nuclear fusion reactions in the hot & dense interiors of stars synthesis nearly all elements

AND they release energy that finally becomes the light we see from stars

To deduce the chemical compositions of stars, we must

analyze their spectra

The basic concept

Fortunately, atoms in stellar atmospheres absorb light at selected colors (wavelengths), giving away their existence

McDonald’s HET and its High Resolution

Spectrograph (HRS) are great tools to study the abundances of SOME

elements in stars

Some elements cannot be observed from the ground! They only have

transitions in the UV

Rb Sr Y Zr Nb Mo Tc Ru Rh Pd Ag Cd In Sn Sb Te I

ScCaK

Xe

Ti V Cr Mn Fe Co Ni Cu Zn Ga Ge As Se Br Kr

H

BeLi

MgNa

Hf Ta W Re Os Ir Pt Au Hg Tl Pb Bi Po At Rn

RaFr

BaCs

Rf Db Sg Bh Hs Mt Uun Uuu Uub

CB O F Ne

ArAl Si P S Cl

N

He

La Ce Pr Nd Pm Sm Eu Gd Tb Dy Ho Er Tm Yb Lu

Ac Th Pa U Np Pu Am Cm Bk Cf Es Fm Md No Lr

Atomic Numbers1

3

11

19

37

55

87

57

89

2

10

18

36

54

86

71

103

Overall HST schematic I

Overall HST schematic II

Overall HST schematic III

HST STIS: just like any simple spectrograph!

Life isn’t fair: a typical HST beautiful image

My beautiful HST STIS image?

But there really is a treasure here …

Blowup this and study

And you cannot do this without HST