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Polarimetry Standards observed at UKIRT
Polarised and Unpolarised Standards Observed at UKIRT
Although polarised and unpolarised standards are occasionally
observed by UKIRT staff, it is important that such targets are also
observed by visiting observers, in the same observing mode that is to
be used on their science targets. However, since the results of these
observations may be of interest to other users, we list below data
kindly provided by visiting observers.
If you have observed a polarised or
unpolarised standard at UKIRT... please consider sharing
your results with the community! Please send details of the target,
values for percentage polarisation and angle, plus details of the
observations (instrument, filter, date of observations, etc.) to Chris Davis at the JAC.
Thanks!
A Note about Unpolarised
Standards: Since unpol. standards by necessity are usually
close to the earth, they are often very bright. Some of the "high"
values for instrumental polarisation given below may therefore be due
to on-source counts being in the non-linear regime (> 5000 counts with
UFTI and UIST). Observers should be wary of over-exposing on
standards. It may even be necessary to defocus the telescope
slightly.
A very basic cshell script is available for calculating the
percent polarisation and angle from the I, Q and U
images produced by the pipeline; simply enter the integrated counts
(from Gaia - aperture photometry):
calc-pol.prg
Imaging Polarimetry with UFTI
On polarised standards, UFTI imaging polarimetry usually
gives angles that are GREATER than
catalogued values by about 9
degrees. The orac-DR automatically applies this correction
to imaging-polarimetry observations (see output from orac-DR for
details).
| Date | Target | Filter | % Pol. | PA (degs) | Notes |
|
|
|
| 18 August 1999 | CMC 511213 | I |
0.58 | - |
Unpolarised standard; high proper motion Carlsberg meridian star (CMC)
Staff obs. |
| 18 August 1999 | CMC 511213 | J |
0.22 | - |
Unpolarised standard; high proper motion Carlsberg meridian star (CMC)
Staff obs. |
| 18 August 1999 | CMC 609784 | H |
0.55 | - |
Unpolarised standard; high proper motion Carlsberg meridian star (CMC)
Staff obs. |
| 18 August 1999 | CMC 609784 | K |
0.10 | - |
Unpolarised standard; high proper motion Carlsberg meridian star (CMC)
Staff obs. |
| 1999? | HD38563C | K |
2.10(0.1) | 87(6) |
Polarised standard: K=2.21%,PA=78deg (Whittet et al., 1992, ApJ, 386, 562)
Staff obs. |
|
|
|
| 16 Jan 2001 | CMC604707 | J |
0.25(0.05) | 168(5) |
Unpolarised standard observed with telescope defocused, used 3.6" aperture:
details in Kishimoto, Antonucci & Blaes, 2005, MNRAS. (astroph/0509341) |
| 16 Jan 2001 | CMC604707 | H |
0.09(0.03) | 105(9) |
Unpolarised standard observed with telescope defocused, used 3.6" aperture:
details in Kishimoto, Antonucci & Blaes, 2005, MNRAS. (astroph/0509341) |
| 16 Jan 2001 | CMC604707 | K' |
0.12(0.04) | 124(10) |
Unpolarised standard observed with telescope defocused, used 3.6" aperture:
details in Kishimoto, Antonucci & Blaes, 2005, MNRAS. (astroph/0509341) |
| 15 Jan 2001 | CMC604919 | J |
0.14(0.02) | 92(5) |
Unpolarised standard observed with telescope defocused, used 7.5" aperture:
details in Kishimoto, Antonucci & Blaes, 2005, MNRAS. (astroph/0509341) |
| 15 Jan 2001 | CMC604919 | H |
0.19(0.01) | 100(2) |
Unpolarised standard observed with telescope defocused, used 7.5" aperture:
details in Kishimoto, Antonucci & Blaes, 2005, MNRAS. (astroph/0509341) |
| 15 Jan 2001 | CMC604919 | K' |
0.14(0.02) | 82(4) |
Unpolarised standard observed with telescope defocused, used 7.5" aperture:
details in Kishimoto, Antonucci & Blaes, 2005, MNRAS. (astroph/0509341) |
|
|
|
| 8 July 2005 | SAO82926 | J |
0.09(0.06) | 157(21) |
Unpolarised standard observed with telescope defocused, used 2.7" aperture:
details in Kishimoto, Antonucci & Blaes, 2005, MNRAS. (astroph/0509341) |
| 8 July 2005 | SAO82926 | K' |
0.11(0.04) | 29(12) |
Unpolarised standard observed with telescope defocused, used 2.7" aperture:
details in Kishimoto, Antonucci & Blaes, 2005, MNRAS. (astroph/0509341) |
| 8 July 2005 | SAO82926 | J |
0.24(0.05) | 99(6) |
Unpolarised standard observed with telescope defocused, used 3.6" aperture:
details in Kishimoto, Antonucci & Blaes, 2005, MNRAS. (astroph/0509341) |
| 8 July 2005 | SAO82926 | K' |
0.24(0.05) | 59(6) |
Unpolarised standard observed with telescope defocused, used 3.6" aperture:
details in Kishimoto, Antonucci & Blaes, 2005, MNRAS. (astroph/0509341) |
| 12 August 2005 | Cyg OB2 no.15 | K |
0.40 | 92 |
Polarised standard: K=0.74%,PA=85deg (Whittet et al., 1992, ApJ, 386, 562)
U/05A/42 - reduced by pipeline. |
- Errors given in brackets.
- UFTI has been on the same telescope (west) port since it was installed.
|
Imaging Polarimetry with UIST
On polarised standards, UIST imaging polarimetry usually
gives angles that are GREATER than
catalogued values by about 24
degrees. The ORAC-DR pipeline automatically applies this correction to
imaging-polarimetry observations.
| Date | Target | Filter | % Pol. | PA (degs) | Notes |
|
|
|
| 21 March 2003 | CMC 809557 | J(MK) |
0.82 | - |
UnPolarised standard; high proper motion Carlsberg meridian star (CMC)
Staff obs. |
| 21 March 2003 | CMC 809557 | H(MK) |
0.83 | - |
UnPolarised standard; high proper motion Carlsberg meridian star (CMC)
Staff obs. |
| 21 March 2003 | CMC 809557 | K(MK) |
0.27 | - |
UnPolarised standard; high proper motion Carlsberg meridian star (CMC)
Staff obs. |
|
|
|
| 26 July 2005 | Cyg OB2 no.3 | J(MK) |
4.3 | 116 |
Polarised standard; J=2.8%,PA=105deg (Whittet et al., 1992, ApJ, 386, 562)
PATT run; data reduced with orac-DR pipeline |
| 21 March 2005 | Cyg OB2 no.3 | K(MK) |
1.5 | 128 |
Polarised standard; K=1.2%,PA=108deg (Whittet et al., 1992, ApJ, 386, 562)
PATT run; data reduced with orac-DR pipeline |
|
|
|
| 18 June 2007 | Ross 128 | H(MK) |
0.22(0.11) | 121 |
UnPolarised standard.
07A PATT run; data reduced by PI (Wisniewski et al.) with IRAF |
| 17 June 2007 | GD319 | H(MK) |
0.43(0.89) | 160 |
UnPolarised standard.
07A PATT run; data reduced by PI (Wisniewski et al.) with IRAF |
| 17 June 2007 | GD319 | H(MK) |
0.30(0.95) | 22 |
UnPolarised standard.
07A PATT run; data reduced by PI (Wisniewski et al.) with IRAF |
| 18 June 2007 | GD319 | H(MK) |
0.75(1.10) | 111 |
UnPolarised standard.
07A PATT run; data reduced by PI (Wisniewski et al.) with IRAF |
| 16 June 2007 | HD147343 | H(MK) |
0.35(0.26) | 115 |
Polarised standard; H=0.45%,PA=87deg (Whittet et al., 1992, ApJ, 386, 562)
07A PATT run; data reduced by PI (Wisniewski et al.) with IRAF |
| 18 June 2007 | HD147343 | H(MK) |
0.44(0.26) | 99 |
Polarised standard; H=0.45%,PA=87deg (Whittet et al., 1992, ApJ, 386, 562)
07A PATT run; data reduced by PI (Wisniewski et al.) with IRAF |
| 17 June 2007 | Cyg OB2 no.3 | H(MK) |
1.85(0.12) | 98 |
Polarised standard; H=1.81%,PA=105deg (Whittet et al., 1992, ApJ, 386, 562)
07A PATT run; data reduced by PI (Wisniewski et al.) with IRAF |
| 23 July 2007 | Cyg OB2 no.3 | H(MK) |
1.10(0.11) | 104 |
Polarised standard; H=1.81%,PA=105deg (Whittet et al., 1992, ApJ, 386, 562)
07A PATT run; data reduced by PI (Wisniewski et al.) with IRAF |
- Errors given in brackets.
- UIST has been on the same (south) telescope port since it was installed in 2002.
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Spectro-Polarimetry with UIST
Observations of polarised standards usually give percentage
polarisation consistent with catalogue values. However, position
angles are often quite random, and dependent on the package used to
reduce the same dataset! Input from users who have observed polarised
standards would be greatly appreciated! At the present time, NO
correction is applied to the PA by the pipeline DR.
| Date | Target | Grism | Wavelength | % Pol. | PA (degs) | Notes |
|
|
|
| March 2003 | Rho Oph Elias 14 | HK | 1.5 to 2.3um |
2.8-1.6 | 19-25 |
Polarised standard: H=3.2%,PA=3deg; K=2.0%,PA=3deg (Whittet et al., 1992, ApJ, 386, 562)
Staff obs./ reduced offline with TSP |
| March 2003 | HD 125184 | HK | 1.5 to 2.3um | 0.3(0.1) | - |
Unpolarised standard, from "Planets, Stars & Nebulae studied with Photopolarimetry",
1974, ed. T. Gehrels, Univ. Arizona Press, pp. 168.
Staff obs./ reduced offline with TSP |
| March 2003 | HD 125184 | Short-K | ~2.2um | 0.35(0.07) | - |
Unpolarised standard, from "Planets, Stars & Nebulae studied with Photopolarimetry",
1974, ed. T. Gehrels, Univ. Arizona Press, pp. 168.
Staff obs./ reduced offline with TSP |
| March 2003 | HD 125184 | Long-L | ~4.0um | 0.5(0.2) | - |
Unpolarised standard, from "Planets, Stars & Nebulae studied with Photopolarimetry",
1974, ed. T. Gehrels, Univ. Arizona Press, pp. 168.
Staff obs./ reduced offline with TSP |
|
|
|
| 18 July 2004 | HD 105193 | HK | 1.6um
2.2um |
2.3
1.7 | -9
-10 |
Polarised standard: H=2.3%,PA=60deg; K=1.7%,PA=60deg (Whittet et al., 1992, ApJ, 386, 562)
Staff obs./ reduced offline with polpack (pipeline gives same results) |
| 18 July 2004 | HD 183143 | HK | 1.6um
2.2um |
1.3
0.7 | -70
-80 |
Polarised standard: H=1.7%,PA=0deg; K=0.7%,PA=0deg (Planets, Stars & Nebulae studied with
Photopolarimetry", 1974, T. Gehrels (ed.), University of Arizona Press, Tuscon)
Staff obs./ reduced offline with polpack (pipeline gives same results) |
| 18 July 2004 | HD 144287 | HK | 1.6um
2.2um |
0.06
0.08 | - |
Unpolarised standard, from "Planets, Stars & Nebulae studied with Photopolarimetry",
1974, ed. T. Gehrels, Univ. Arizona Press, pp. 168.
Staff obs./ reduced offline with polpack
(pipeline gives same results) |
|
|
|
| 8 July 2005 | HD 150193 | IJ | 1.1um
1.3um |
6.6(1.0)
2.8(0.1) | 12(2)*
29(2)* |
Polarised standard: I=5.0%,PA=57deg; J=3.3%,PA=57deg (Whittet et al., 1992, ApJ, 386, 562)
Staff obs./ reduced with pipeline; Values are mean over 100 pixels (~0.06um) |
| 8 July 2005 | HD 150193 | JH | 1.3um
1.65um |
2.9(0.1)
2.1(0.1) | 27(1)*
28(1)* |
Polarised standard: J=3.3%,PA=57deg; H=2.3%,PA=60deg (Whittet et al., 1992, ApJ, 386, 562)
Staff obs./ reduced with pipeline; Values are mean over 100 pixels (~0.08um) |
| 8 July 2005 | HD 150193 | HK | 1.65um
2.2um |
2.2(0.1)
1.7(0.1) | 28(1)*
29(1)* |
Polarised standard: H=2.3%,PA=60deg; K=1.7%,PA=60deg (Whittet et al., 1992, ApJ, 386, 562)
Staff obs./ reduced with pipeline; Values are mean over 100 pixels (~0.11um) |
| 8 July 2005 | HD 144287 | IJ | 1.1um
1.3um |
0.93(0.2)
0.41(0.1) | - |
Unpolarised standard, from "Planets, Stars & Nebulae studied with Photopolarimetry",
1974, ed. T. Gehrels, Univ. Arizona Press, pp. 168.
Staff obs./ reduced with pipeline; Values are mean over 100 pixels (~0.06um) |
| 8 July 2005 | HD 144287 | JH | 1.3um
1.65um |
0.25(0.1)
0.19(0.1) | - |
Unpolarised standard, from "Planets, Stars & Nebulae studied with Photopolarimetry",
1974, ed. T. Gehrels, Univ. Arizona Press, pp. 168.
Staff obs./ reduced with pipeline; Values are mean over 100 pixels (~0.08um) |
| 8 July 2005 | HD 144287 | HK | 1.65um
2.2um |
0.26(0.09)
0.41(0.12) | - |
Unpolarised standard, from "Planets, Stars & Nebulae studied with Photopolarimetry",
1974, ed. T. Gehrels, Univ. Arizona Press, pp. 168.
Staff obs./ reduced with pipeline; Values are mean over 100 pixels (~0.11um) |
|
|
|
| 22 July 2005 | CyG OB2 No.3 | HK | 1.65um
2.2um |
1.7
1.0 | 138
135 |
Polarised standard: H=1.8%,PA=105deg; K=1.2%,PA=108deg ("Planets, Stars & Nebulae studied with
Photopolarimetry", 1974, T. Gehrels (ed.), University of Arizona Press, Tuscon, p. 170)
Reduced with pipeline; Values are approximate |
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|
|
- Click on Grism name to see data, where available.
- Errors given in brackets.
- UIST has been on the same (south) telescope port since it was installed in 2002.
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Spectro-Polarimetry with CGS4
Note that, because the prism in CGS4 comes before the slit
in the optical train, we encourage users to use UIST for all
spectro-polarimetry.
| Date | Target | Wavelength | % Pol. | PA (degs) | Notes |
|
|
|
| 26 Sep 1999 | HD 10476/202573 | 1.2um |
0.17 | 122.5 |
UnPolarised standards, data from two sources combined. Details in
Oudmaijer et al. (2005), MNRAS |
|
|
|
| 26 Sep 1999 | HD 23512 | 1.2um |
1.34 | 29.5 |
Polarised standard; predicted pol is J=1.19%,PA= 30deg (extrapolating Serkowski
from the R-band values of Hsu & Breger 1982, ApJ, 262, 732);
Oudmaijer et al. (2005), MNRAS |
| 26 Sep 1999 | HD 43384 | 1.2um |
1.50 | 171.7 |
Polarised standard; predicted pol is J=1.23%,PA= 171deg (extrapolating Serkowski
from the R-band values of Hsu & Breger 1982, ApJ, 262, 732);
Oudmaijer et al. (2005), MNRAS |
| 26 Sep 1999 | HD 7927 | 1.2um |
1.40 | 96.5 |
Polarised standard; predicted pol is J=1.29% (extrapolating Serkowski
from the R-band values of Hsu & Breger 1982, ApJ, 262, 732);
Oudmaijer - private communication. |
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