Flight Planning for 1st Light

1SOFIA

Stratospheric Observatory for Infrared

Astronomy

Flight Planning for 1st Light

Allan Meyer and Eric Becklin

SSSC 29 Sept 2009

2SOFIA


Astronomy

Flight Planning for “TA charact., 1st light”

• TA characterization: pointing stability, other performance & functionality aspects potentially affected by flight environment

• “first light” image from FORCAST: not science, for demonstration purposes only. Will not drive any new requirements or schedule delays

• Development phase constraints on the aircraft, and the character of the “IR Sky” dictate & severely limit the content of feasible flight plans. (Probably also true for TA characterization without FORCAST)

• Aircraft Constraints:– Door fully open but fixed at 23° elevation for TA char., 1st light

– 200 nautical mile radius limit from DAOF*

– Offshore limit ~50 miles

– No Mexico overflight => Dec. > -35°

– ~ 6 hour flight duration

– Sun at least ~10° below horizon

– 35K observing altitude, winter / spring, 2010

*late note: Platform Project is considering an increase of the radius limit

3SOFIA


Astronomy

Location of Geographic Limits

• 200 nm radius limit

• Off-shore limit

Mexico border

4SOFIA


Astronomy

Flight Plan Science Constraints

• TA characterization– Pointing stability

– Image quality (i.e. confirm diffraction limit from HIPO Shack-Hartmann)

– Chopping performance

– 5 - 25 µm fast imaging (50 - 500 Hz) of IR bright stars (M <+2)

• “First light”: – demonstration of science capability:

Point source okay; one extended source could be attempted.

– TBD s, 5 - 40 µm

• IR bright stars for setup, fast imaging (TA char.), & demonstration of FORCAST performance.

• FIR bright extended source(s) (H II/SFRs, planet) for science demonstration.

• Trackable with current FPI, mag. limit ~12 (offset tracking or FFI tracking if needed)

5SOFIA


Astronomy

Getting a List of Appropriate IR Stars

• The appropriate list of visible & mid-IR bright stars is the first step

• FORCAST sensitivity at ~500 Hz readout rate– J. Adams (Cornell, Dec. ‘08) calculation for 16 MIRAC stds.

– At 508 Hz readout rate, S/N = 50 for 56 Jy at 5.35 µm

– Vega ( Lyr, M = 0, 158 Jy) S/N = 140

• Lists from several online sources have been downloaded for trial use

• The best list appears to be based on the IRAS Point Source Catalog (PSC), with limits on 12 µm flux, 12µm/25µm flux ratio, & appropriate ID.SIMBAD ident.

typeR.A.

(2000)Dec. Gal.

long.244.4

Gal. lat.

V Kspec. type

F12 / F25

l Pup

Em*

7 43 48.47 -28 57 17.4 -2.54 4.0 2.5A3Iab:

1.8

12 Lib

Star

14 54 20.13 -24 38 31.9 335.5 30.35 5.3 2.2K2/K3III

4.1

13 PsA

Star

22 4 23.84 -29 54 59.5 18.5 -53.40 6.5 2.0K5III

4.9

24 Cap

*in**

21 7 7.67 -25 0 21.1 22.0 -40.01 4.5 0.5K7III

3.8

27 Sco

Star

16 57 11.18 -33 15 34.2 350.5 6.07 5.5 1.6K5III

4.2

36 Lib

Star

15 34 37.32 -28 2 49.1 341.5 22.35 5.1 1.9K4III

3.7

43 Oph

Star

17 23 21.59 -28 8 34.2 358.0 4.54 5.3 1.5K5III

4.4

49 Hya

Star

14 6 22.30 -26 40 56.5 323.0 33.25 3.3 0.8K1III-IV

4.5

50 Hya

Star

14 12 46.02 -27 15 40.3 324.3 32.21 5.1 2.4K3III

4.1

52 Eri

Star

4 35 33.04 -30 33 44.4 231.0 -41.31 3.8 1.6G8IIIa

3.8

AF For

PulsV*

3 8 37.52 -26 26 46.9 219.6 -59.47 8.6 2.1M5III

3.5

AH Sco

semi-regV*

17 11 17.02 -32 19 30.7 353.1 4.27 7.5 0.4M4III:

1.8

AI For

V*

3 19 34.91 -24 7 22.4 216.2 -56.59 5.7 1.1M1III

3.7

AK Pyx

Irregular_V*

8 48 14.63 -28 38 19.7 252.0 9.35 6.5 0.5M5III

2.7

AL Pyx

Irregular_V*

9 1 6.28 -27 30 56.7 252.9 12.27 7.2 2.4M1III

3.9

alf Sco

semi-regV*

16 29 24.46 -26 25 55.2 351.9 15.06 1.1 ~M1.5Iab-b

4.6

Alpha PsA

V*

22 57 39.05 -29 37 20.1 20.5 -64.91 1.2 ~A4V

3.8

AM For

semi-regV*

3 43 10.03 -31 1 9.4 229.4 -52.51 7.2 1.4M4III

3.7

AO Pyx

Irregular_V*

9 14 47.65 -33 40 56.5 259.6 10.41 8.8 2.1M5/M6III

3.5

6SOFIA


Astronomy

Candidate Targets for Feasibility Trials

• FORCAST 2006 “Design Reference Mission”:– ~100 assorted galactic & extragalactic targets– 28 calibration stars: Boo, Tau, CMa, etc. N mag. ~0 to -4

• NOAO list + UKIRT stds. + Cat. IR Obs. (Gezari)– M<+1, > -35° => N = 288

• IRAS PSC (using CDS Vizier) + SIMBAD idents– 12 µm flux > 25 µm flux for stellar sources– Dec. strip for ~23° elevation west heading: -34° to -24°– N ~ 250 to 310 depending on 12µm flux cutoff (e.g. 10 Jy, or gal. b modulated)

• Catalog of Pstns. of IR Stellar Sources (CPIRSS, Hindsley et al. 1994)– IRAS PSC sources confidently identified as stars (Tycho, Hipparcos, etc.)

– Dec. -34° to -24°, F(12µm) > 5 Jy, & F(12µm) > F(25µm) => N = 263

7SOFIA


Astronomy

CPIRSS F(12 µm) > 5 Jy, -34° < Dec. < -24°

-36°

-34°

-32°

-30°

-28°

-26°

-24°

-22°

-20°

024681012141618202224Right Ascension (hrs, J2000)

Decli

nati

on

(J2

00

0)

Sky Distribution

QuickTime™ and a decompressor

are needed to see this picture.

FORCAST DRM (green), NOAO + UKIRT + CIO bright IR stars (M < +1), Dec. >-35°

8SOFIA


Astronomy

Feasibility: example TA char. Flight plan

ETD: 0320Z Mar. 15, 2010

ETE: 06+50

9SOFIA


Astronomy

Summary of Observing Legs

Leg no. Object V M F(12µm)Leg

DurationObject elevation

range

4 Saturn 0 30 m 19° - 25°

5 S Cep 7.5 -1.7 383 Jy 24 m 23°

7 HIP 43093 7.2 +1.8 20 Jy 45 m 24° - 23°

9 NGC 6543 9 +7 8 Jy 35 m 22° - 25°

10 NSV 4862 4.3 +1 20 Jy 45 m 23°

12 Gamma Cep 4.2 ~+0.7 21 Jy 37 m 23°

14 W Hya 7.5 - 3.9 4200 Jy 35 m 22° - 24.5°

16 HIP 11978 6,8 +1.1 12 Jy 30 m 23° - 22°

Sum of observing leg durations = 4.7 h

Net time with objects in 22° - 24° elev. range ~4.1 h

10SOFIA


Astronomy

“1st Light” & Short Science: availability of M42, Sgr A (winter / spring )

M 42, Sgr A Max. Leg Duration vs. Date( TA Elev. Range 23° - 30° )

0

10

20

30

40

50

60

70

80

90

1-Jan 15-Jan 29-Jan 12-Feb 26-Feb 12-Mar 26-Mar 9-Apr 23-Apr 7-May

Date

Max.

Leg D

ura

tion (

23°

- 30°)

M 42 setting

M 42 rising

M 42 rsing & setting

Sgr A (rising)

• M 42 available both rising & setting thru end of Jan. (8-hr flight can catch both.)

• After that only one leg possible, limited by 23°- 30° elev. range to 40 minutes until ~Apr. 20.

• Sgr A starts to become available in mid-March. (Leg duration limited to 50 min. by 200 nautical mile radius range limit.)

Documents

Flight Planning for 1st Light