Published on SOAR (http://www.ctio.noirlab.edu/soar)

Home > Astronomers > Optical Instrumentation at SOAR > Goodman High Throughput Spectrograph > Calibration Information

Calibration Information

Goodman Comparison Lamps

Updated Mar 2021

The SOAR Instrument Support Boxes (ISBs) contain facility calibration units containing both continuum sources for flat fielding and line sources for wavelength calibration. 

The wavelength calibration lamps normally used with the Goodman spectrograph are: HgAr, CuHeAr, Ne, and Ar.  An Fe lamp is also available.
The comparison lamps can be activated from the instrument GUI by you, or you can ask the Telescope Operator (TO) to do it for you from his technical GUI.
Note that you need to make a slow, substantial mouse click on the particular lamp in order for it to actually get the input and turn on or off (a quick click may make the green light go on or off but not turn on/off the lamp). If in doubt, check with the TO. The Fe lamp is not featured in the GUI and you need to ask the TO to rutn it ON/OFF for you. When obtaining comparison lamps, make sure you are in Spectroscopic Mode and that the TO has put the pickup mirror in.

In Figure 1 at below we show the CuHeAr arc lamp spectra for most of our pre-defined spectroscopic modes. NOTE: the 300 l/mm grating has now been replaced by the 400 l/mm grating.

In Figure 2 below we show the HgAr arc lamp spectra for most of our pre-defined spectroscopic modes. NOTE: the 300 l/mm grating has now been replaced by the 400 l/mm grating.

In the following table containing plots of the comparison lamps made with various gratings and setups. However, for the latest library of comparison lamp spectra, we advise you use the comparison lamp spectra at this link. [6]
 

Grating Setup Lamp Wavelength
Coverage of the Plot
Goodman Comparison Lamp Spectra
400 M1 HgAr 3000-7000 (Full range) [7]
400 M1 HgAr 3000-5000 (Zoom) [8]
400 M1 HgAr 5000-7000 (Zoom) [9]
400 M2 HgAr 5000-9000 (Full range) [10]
400 M2 HgAr 5000-9000 (Zoomed/split) [11]
600 UV,Blue,Mid,Red HgAr 3600-9000 (6 plots) [12]
600 UV,Blue,Mid CuHeAr 3600-6500 [13]
930 M1 HgAr 3000-4500 (Full range & zoom) [14]
930 M2 HgAr 3750-5500 (Full range & zoom) [15]
930 M3 HgAr 4750-6250 (Full range & zoom) [16]
930 M4 HgAr 5500-7200 (Full range & zoom) [17]
930 M5 HgAr 6400-8000 (Full range & zoom) [18]
930 M6 HgAr 7250-8750 (Full range & zoom) [19]
930 M2 CuHeAr 3750-5500 (Full range & zoom) [20]
930 M3 CuHeAr 4750-6250 (Full range & zoom) [21]
930 M4 CuHeAr 5500-7200 [22]
930 M5 CuHeAr 6400-8000 [23]
930 M6 CuHeAr 7250-8750 [24]
1200 M5 HgArNe 3600-8700 (7 plots) [25]
1200 M1,M2,M3,M4,M5,M6,M7 CuHeAr 3600-8700 (7 plots) [26]
2100 650nm (Littrow) Ne 6150-6720 [27]

Useful links:

The KPNO Spectral Atlas Central [28] is a useful resource for comparison lamp spectra

Goodman Dome/Quartz flats and Comps Exposure Times

Updated 02 Mar 2021

Goodman RED camera typical DOME FLAT lamp exposure times (for 2x2 binning, 344ATTN3 readout mode)

Mode Type Slit Lamp (%) / Exp (s) Texp
(s)		  ADU
400M1 no filter Spec 1 100 7 28000 (1)
400M2 +GG455 flter Spec 1 100 5 25000 (1)
600MID + GG395 filter Spec 1 100 12 29000 (1)
930M2 no filter Spec 1 100 60 27000 (1)
SDSS-g Img --- 30 2.5 21000 (2)
SDSS-r Img --- 15 1.5 24000 (2)
SDSS-i Img --- 10 1 27000 (2)
VR Img --- 10 3 25500 (2)

(1)  Max ADU count, at red end of spectrum
(2) Average ADU count

Goodman RED camera typical QUARTZ FLAT lamp exposure times (344ATTN3 readout mode)
 

Mode Binning Slit
(")		 Lamp (%) / Exp (s) Texp
(s)		 MAX ADU
400M1 no filter 2x2 1 70 3 39600
400M2 +GG455 flter 2x2 1 70 1.5 34000
600MID + GG395 filter 2x2 1 70 5 36000
930M2 no filter 2x2 1 100 3.5 29500
2100@650+GG455 filter 1x2 0.45 100 15 24000

Goodman RED camera typical COMPARISON lamp exposure times (200ATTN0 readout mode)

Mode Binning Slit
(")		 ARC LAMP Exp
(s)
400M1 no filter 2x2 1 HgArNe 0.5
400M2 + GG455 filter 2x2 1 HgArNe 0.5
600MID + GG395 filter 2x2 1 HgArNe 0.5
930M2 no filter 2x2 1 Cu(HeAr) 120
2100@650+GG455 filter 1x2 0.45 HgArNe 0.5
2100@5577 1x2 0.45 HgArNe 1
 

----------------------------------------------------------------------------------------------------------------------------

Goodman BLUE camera typical DOME FLAT lamp exposure times (for 2x2 binning, 200ATTN0 readout mode)

Mode Type Slit Lamp (%) / Exp (s) Texp
(s)		  ADU
400M1 no filter Spec 1 100 7 29600 (1)
400M2 +GG455 flter Spec 1 100 7 30000 (1)
600MID + GG395 filter Spec 1 100 12 29500 (1)
930M2 no filter Spec 1 100 45 23600 (1)
SDSS-g Img --- 40 1.5 31000 (2)
SDSS-r Img --- 15 1.5 24600 (2)
SDSS-i Img --- 10 1 22000 (2)
VR Img --- 15 1 25000 (2)

(1)  Max ADU count, at red end of spectrum
(2) Average ADU count

Goodman BLUE camera typical QUARTZ FLAT lamp exposure times (200ATTN0 readout mode)

Mode Binning Slit
(")
 		 Lamp (%) Exp
(s)		 MAX ADU
400M1 no filter 2x2 1 70 2.5 30900
400M2 + GG455 filter 2x2 1 70 2 31800
600MID + GG395 filter 2x2 1 70 4 28700
930 M2 no  filter 2x2 1 100 3 29000

Goodman BLUE camera typical COMPARISON lamp exposure times (for 2x2 binning, 200ATTN0 readout mode)

Mode ARC LAMP Exp
(s)
400M1 no filter HgArNe 0.3
400M2 + GG455 filter HgArNe 0.3
600MID + GG395 filter HgArNe 0.3
930M2 no filter Cu(HeAr) 90
 

Goodman spectrograph typical focus values

Updated 23 Jul 2020

Here we provide typical focus values for the Goodman instrument. The instrument focus is usually set once per night, and is done as the first step before afternoon calibrations. Note that the focus is dependent on ambient temperature, so values will change significantly from summer to winter, in fact, variations of up to ~500 units could happen from one observing run to another. Also, the depth of focus is roughly 100 units, so focus values within +/- 50 units can be considered consistent with no focus difference.
The BLUE camera focus values should be mostly positive; RED camera focus values are mostly negative.

See how to perform a spectroscopic focus measurement [29].

See how to perform an imaging focus measurement [30].

The following values are representative. In some cases we provide actual measured values obtained on different dates to illustrate the variations; both blue and red cameras are affected by focus variations as a function of temperature. You should perform a focus sequence every afternoon.

Red Camera spectroscopic focus values:

Grating Mode Camera
Temp (C)		 Focus
400 M1 19 -300
400 M1 16 -600
400 M1 13 -660
400 (+GG455) M2 19 -990
400 (+GG455) M2 16 -1200
400 (+GG455) M2 11 -1300
400 M2 16 -250
400 M2 11 -690
600red (+GG385) Mid 17 -1770
600red (+GG495) Red 17 -992
600old (+GG385) Mid 15 -1540
1200 M2 17 -700
1800 @700nm 13 -825
1800 @660nm 19 -460
2100 @650nm 16 -200
2100 @650nm 13 -555
2100 @650nm 17 -376

 

Blue Camera spectroscopic focus values:

Grating Mode Camera
Temp (C)		 Focus
400 M1 17 1615
400 M1 11 1320
400 (+GG455) M2 11 773
600blue UV 17 1650
600blue Blue 17 1650
600old UV 11 1370
600old Blue 11 1440
600old (+GG385) Mid 11 880
600old (+GG495) Red 11 1350
600blue (+GG385) Mid 17 820
600blue (+GG495) Red 17 1650

 

Red Camera imaging focus values:

Filter Lamps/(%) Exp
(s)		 Camera
Temp (C)		 Focus
None Dome/5 0.5 10 -1130
B Quartz/50 2 19 -715
V Dome/20 0.5 10 -580
R Quartz/50 1 19 -1320
VR Dome/25 0.5 16 -470
VR Dome/25 0.5 11 -814
SDSS-u Dome/20 1 10  
SDSS-g Dome/20 1 10  
SDSS-r Dome/20 1 10 -700
SDSS-i Dome/20 1 10 -900
SDSS-z Dome/20 1 10 -1250
  Dome/20 1 10  

 

Blue Camera imaging focus values:

Filter Lamps (%) Exp
(s)		 Camera
Temp (C)		 Focus
SDSS-g Quartz/50 4 11 1100
SDSS-r Quartz/50 1 11 990
SDSS-i Quartz/50 0.3 11 860
SDSS-z Quartz/50 0.5 11 540

Hamuy Spectrophotometric Standards

M. Hamuy led a group at CTIO to obtain observations of 10 secondary spectrophotometric standards from Taylor (1984) [31] and 19 tertiary spectrophotometric standards from Stone & Baldwin (1983) [32] and Stone (1977) [33]. These results were published in two papers:(1) Hamuy et al. (1992) [34] and (2) Hamuy et al. (1994) [35]. The former paper covers wavelengths from 3300Å to 7550Å and the latter paper covers wavelengths from 6000Å to 10500Å. The latter paper also combines both sets of observations and presents AB magnitudes for the 10 secondary standards at 16Å intervals from 3300Å to ~10400Å and for the 19 tertiary standards at 50Å intervals from 3300Å to ~10300Å. The AB magnitudes are converted to flux (erg cm-2 s-1Å-1) using the formula:

AB Mag = -2.5 alog10(Fν) - 48.59 where Fν is in erg cm-2 s-1 Hz-1.

 

 

Secondary Spectrophotometric Standard Stars
HR# Star RA
(J2000)		 Dec
(J2000)		 MKType (U-B) (B-V) V (V-R)KC (V-I)KC
718 ξ2 Cet 02:28:09.54 +08:27:36.2 B9 III -0.107 -0.056 4.279 -0.023 -0.063
1544 π2 Ori 04:50:36.69 +08:54:00.7 A1 V ... 0.01 4.355 0.014 0.039
3454 η Hya 08:43:13.46 +03:23:55.1 B3 V -0.743 -0.200 4.295 -0.083 -0.200
4468 θ Crt 11:36:40.91 -09:48:08.2 B9.5 V -0.18 -0.07 4.700 -0.023 -0.063
4963 θ Vir 13:09:56.96 -05:32:20.5 A1 IV -0.01 -0.00 4.375 0.003 0.010
5501 108 Vir 14:45:30.25 +00:43:02.7 B9.5 V -0.080 -0.023 5.681 0.004 -0.026
7001 α Lyr 18:36:56.33 +38:47:01.1 A0 V 0.00 0.00 0.03 -0.037 -0.045
7596 58 Aql 19:54:44.80 +00:16:24.6 A0 II1 -0.01 0.10 5.62 ... ...
7950 ε Aqr 20:47:40.55 -09:29:44.7 A1 V 0.029 -0.001 3.778 -0.005 -0.010
8634 ζ Peg 22:41:27.64 +10:49:53.2 B8 V -0.24 -0.09 3.40 -0.037 -0.079
9087 29 Psc 00:01:49.42 -03:01:39.0 B7 III-IV -0.501 -0.136 5.120 -0.052 -0.122

 

Tertiary Spectrophotometric Standard Stars
Star RA
(J2000)		 Dec
(J2000)		 Type (U-B) (B-V) V (V-R)KC (R-I)KC PM (RA)
(" yr-1)		 PM (Dec)
(" yr-1)		  Plots
1CD-34 241 00:41:46.9 -33:39:09 f -0.065 +0.478 11.229 +0.295 +0.289 -0.45 -0.25 finder [36]/spectrum [37]
LTT 1020 01:54:49.7 -27:28:29 g -0.186 +0.557 11.522 +0.361 +0.364 0.33 -0.21 finder [38]/spectrum [39]
EG 21 03:10:30.4 -68:36:05 DA -0.661 +0.039 11.379 -0.093 -0.064 0.00 -0.30 finder [40]/spectrum [41]
LTT 1788 03:48:22.2 -39:08:35 f -0.281 +0.469 13.155 +0.317 +0.332 0.24 -0.19 finder [42]/spectrum [43]
LTT 2415 05:56:24.2 -27:51:26 ... -0.215 +0.400 12.214 +0.267 +0.293 0.30 -0.18 finder [44]/spectrum [45]
Hiltner 600 06:45:13.5 +02:08:15 B1 -0.574 +0.179 10.441 +0.120 +0.140 ... ... finder [46]/spectrum [47]
LTT 3218 08:41:32.4 -32:56:33 DA -0.574 +0.220 11.858 +0.096 +0.111 -1.10 1.34 finder [48]/spectrum [49]
LTT 3864 10:32:13.8 -35:37:42 f -0.167 +0.495 12.171 +0.323 +0.329 -0.34 -0.01 finder [50]/spectrum [51]
LTT 4364 11:45:42.9 -64:50:29 C2 -0.664 +0.162 11.504 +0.173 +0.127 6.19 -0.33 finder [52]/spectrum [53]
2Feige 56 12:06:47.3 +11:40:13 sdB8 ... -0.13 11.06 ... ... -0.007 -0.007 finder [54]/spectrum [55]
LTT 4816 12:38:50.7 -49:47:58 DA -0.656 +0.166 13.794 +0.013 +0.027 -0.86 -0.13 finder [56]/spectrum [57]
CD-32 9927 14:11:46.3 -33:03:15 A4 ... +0.349 10.444 +0.324 +0.014 -0.004 0.007 finder [58]/spectrum [59]
LTT 6248 15:38:59.8 -28:35:34 a -0.197 +0.491 11.797 +0.319 +0.345 -0.25 -0.18 finder [60]/spectrum [61]
EG 274 16:23:33.7 -39:13:48 DA -0.969 -0.144 11.029 -0.093 -0.096 0.10 -0.01 finder [62]/spectrum [63]
LTT 7379 18:36:26.2 -44:18:37 G0 -0.020 +0.605 10.225 +0.366 +0.366 -0.22 -0.16 finder [64]/spectrum [65]
LTT 7987 20:10:57.1 -30:13:03 DA -0.670 +0.046 12.230 -0.062 -0.078 -0.43 -0.24 finder [66]/spectrum [67]
LTT 9239 22:52:40.9 -20:35:27 f -0.110 +0.609 12.068 +0.397 +0.372 0.10 -0.33 finder [68]/spectrum [69]
Feige 110 23:19:58.3 -05:09:56 sdO8 -1.09 -0.05 11.50 -0.47 -0.175 -0.011 0.0 finder [70]/spectrum [71]
LTT 9491 23:19:35.2 -17:05:28 DC -0.843 +0.007 14.112 +0.045 +0.031 0.27 0.05 finder [72]/spectrum [73]
Notes:
1CD-34 241 is mistakenly named LTT 377 in Stone and Baldwin (1983) and Hamuy et al. (1992 & 1994).
2The coordinates of Feige 56 are given incorrectly in Hamuy et al. (1992).

 

Radial Velocity Standards

One of the latest and most complete lists of radial velocity standard stars is that by Soubiran et al. 2013, A&A, 552A, 64 (ADS link [74]):

"The catalogue of radial velocity standard stars for Gaia. I. Pre-launch release."

This catalog contains 1420 stars with data over a baseline of over 6 yr,  with an overall stability of about 300 m/s

The data in their Table 4, can be accessed in the CDS service by click on this link. [75]

Source URL: http://www.ctio.noirlab.edu/soar/content/calibration-information

Links
[1] https://soardocs.readthedocs.io/projects/lamps/en/latest/
[2] http://www.ctio.noirlab.edu/soar/content/goodman-domequartz-flats-and-comps-exposure-times
[3] http://www.ctio.noirlab.edu/soar/content/goodman-spectrograph-typical-focus-values
[4] http://www.ctio.noirlab.edu/soar/content/hamuy-spectrophotometric-standards
[5] http://www.ctio.noirlab.edu/soar/content/radial-velocity-standards
[6] https://goodman.readthedocs.io/projects/lamps/en/latest/
[7] http://www.ctio.noirlab.edu/soar/sites/default/files/Instrument_Plots/400m1_HgAr_3000-7000.pdf
[8] http://www.ctio.noirlab.edu/soar/sites/default/files/Instrument_Plots/400m1_HgAr_3000-5000.pdf
[9] http://www.ctio.noirlab.edu/soar/sites/default/files/Instrument_Plots/400m1_HgAr_5000-7000.pdf
[10] http://www.ctio.noirlab.edu/soar/sites/default/files/GOODMAN/HgArNe_400M2_GG455_full.pdf
[11] http://www.ctio.noirlab.edu/soar/sites/default/files/GOODMAN/HgArNe_400M2_GG455_split.pdf
[12] http://www.ctio.noirlab.edu/soar/sites/default/files/Instrument_Plots/hgar_600.pdf
[13] http://www.ctio.noirlab.edu/soar/sites/default/files/GOODMAN/CuHeAr_600_Blue_full.pdf
[14] http://www.ctio.noirlab.edu/soar/sites/default/files/Instrument_Plots/HgAr_930m1.pdf
[15] http://www.ctio.noirlab.edu/soar/sites/default/files/Instrument_Plots/HgAr_930m2.pdf
[16] http://www.ctio.noirlab.edu/soar/sites/default/files/Instrument_Plots/HgAr_930m3.pdf
[17] http://www.ctio.noirlab.edu/soar/sites/default/files/Instrument_Plots/HgAr_930m4.pdf
[18] http://www.ctio.noirlab.edu/soar/sites/default/files/Instrument_Plots/HgAr_930m5.pdf
[19] http://www.ctio.noirlab.edu/soar/sites/default/files/Instrument_Plots/HgAr_930m6.pdf
[20] http://www.ctio.noirlab.edu/soar/sites/default/files/Instrument_Plots/CuHeAr_930m2.pdf
[21] http://www.ctio.noirlab.edu/soar/sites/default/files/Instrument_Plots/CuHeAr_930m3.pdf
[22] http://www.ctio.noirlab.edu/soar/sites/default/files/Instrument_Plots/CuHeAr_930m4.pdf
[23] http://www.ctio.noirlab.edu/soar/sites/default/files/Instrument_Plots/CuHeAr_930m5.pdf
[24] http://www.ctio.noirlab.edu/soar/sites/default/files/Instrument_Plots/CuHeAr_930m6.pdf
[25] http://www.ctio.noirlab.edu/soar/sites/default/files/GOODMAN/HgArNe_1200M5_GG455_full.pdf
[26] http://www.ctio.noirlab.edu/soar/sites/default/files/Instrument_Plots/cuhear_1200.pdf
[27] http://www.ctio.noirlab.edu/soar/sites/default/files/Instrument_Plots/GHTS_2100_650nm_Ne.2.pdf
[28] http://iraf.noao.edu/specatlas/
[29] http://www.ctio.noirlab.edu/soar/content/observing-goodman#S5c
[30] http://www.ctio.noirlab.edu/soar/content/imaging-focus
[31] http://adsabs.harvard.edu/abs/1984ApJS...54..259T
[32] http://adsabs.harvard.edu/abs/1983MNRAS.204..347S
[33] http://adsabs.harvard.edu/abs/1977ApJ...218..767S
[34] http://adsabs.harvard.edu/abs/1992PASP..104..533H
[35] http://adsabs.harvard.edu/abs/1994PASP..106..566H
[36] http://www.ctio.noirlab.edu/soar/sites/default/files/GOODMAN/Hamuy/cd-34241_dss.pdf
[37] http://www.ctio.noirlab.edu/soar/sites/default/files/GOODMAN/Hamuy/cd-34241_spec.pdf
[38] http://www.ctio.noirlab.edu/soar/sites/default/files/GOODMAN/Hamuy/ltt1020_dss.pdf
[39] http://www.ctio.noirlab.edu/soar/sites/default/files/GOODMAN/Hamuy/ltt1020_spec.pdf
[40] http://www.ctio.noirlab.edu/soar/sites/default/files/GOODMAN/Hamuy/eg21_dss.pdf
[41] http://www.ctio.noirlab.edu/soar/sites/default/files/GOODMAN/Hamuy/eg21_spec.pdf
[42] http://www.ctio.noirlab.edu/soar/sites/default/files/GOODMAN/Hamuy/ltt1788_dss.pdf
[43] http://www.ctio.noirlab.edu/soar/sites/default/files/GOODMAN/Hamuy/ltt1788_spec.pdf
[44] http://www.ctio.noirlab.edu/soar/sites/default/files/GOODMAN/Hamuy/ltt2415_dss.pdf
[45] http://www.ctio.noirlab.edu/soar/sites/default/files/GOODMAN/Hamuy/ltt2415_spec.pdf
[46] http://www.ctio.noirlab.edu/soar/sites/default/files/GOODMAN/Hamuy/hiltner600_dss.pdf
[47] http://www.ctio.noirlab.edu/soar/sites/default/files/GOODMAN/Hamuy/hiltner600_spec.pdf
[48] http://www.ctio.noirlab.edu/soar/sites/default/files/GOODMAN/Hamuy/ltt3218_dss.pdf
[49] http://www.ctio.noirlab.edu/soar/sites/default/files/GOODMAN/Hamuy/ltt3218_spec.pdf
[50] http://www.ctio.noirlab.edu/soar/sites/default/files/GOODMAN/Hamuy/ltt3864_dss.pdf
[51] http://www.ctio.noirlab.edu/soar/sites/default/files/GOODMAN/Hamuy/ltt3864_spec.pdf
[52] http://www.ctio.noirlab.edu/soar/sites/default/files/GOODMAN/Hamuy/ltt4364_dss.pdf
[53] http://www.ctio.noirlab.edu/soar/sites/default/files/GOODMAN/Hamuy/ltt4364_spec.pdf
[54] http://www.ctio.noirlab.edu/soar/sites/default/files/GOODMAN/Hamuy/feige56_dss.pdf
[55] http://www.ctio.noirlab.edu/soar/sites/default/files/GOODMAN/Hamuy/feige56_spec.pdf
[56] http://www.ctio.noirlab.edu/soar/sites/default/files/GOODMAN/Hamuy/ltt4816_dss.pdf
[57] http://www.ctio.noirlab.edu/soar/sites/default/files/GOODMAN/Hamuy/ltt4816_spec.pdf
[58] http://www.ctio.noirlab.edu/soar/sites/default/files/GOODMAN/Hamuy/cd-329927_dss.pdf
[59] http://www.ctio.noirlab.edu/soar/sites/default/files/GOODMAN/Hamuy/cd-329927_spec.pdf
[60] http://www.ctio.noirlab.edu/soar/sites/default/files/GOODMAN/Hamuy/ltt6248_dss.pdf
[61] http://www.ctio.noirlab.edu/soar/sites/default/files/GOODMAN/Hamuy/ltt6248_spec.pdf
[62] http://www.ctio.noirlab.edu/soar/sites/default/files/GOODMAN/Hamuy/eg274_dss.pdf
[63] http://www.ctio.noirlab.edu/soar/sites/default/files/GOODMAN/Hamuy/eg274_spec.pdf
[64] http://www.ctio.noirlab.edu/soar/sites/default/files/GOODMAN/Hamuy/ltt7379_dss.pdf
[65] http://www.ctio.noirlab.edu/soar/sites/default/files/GOODMAN/Hamuy/ltt7379_spec.pdf
[66] http://www.ctio.noirlab.edu/soar/sites/default/files/GOODMAN/Hamuy/ltt7987_dss.pdf
[67] http://www.ctio.noirlab.edu/soar/sites/default/files/GOODMAN/Hamuy/ltt7987_spec.pdf
[68] http://www.ctio.noirlab.edu/soar/sites/default/files/GOODMAN/Hamuy/ltt9239_dss.pdf
[69] http://www.ctio.noirlab.edu/soar/sites/default/files/GOODMAN/Hamuy/ltt9239_spec.pdf
[70] http://www.ctio.noirlab.edu/soar/sites/default/files/GOODMAN/Hamuy/feige110_dss.pdf
[71] http://www.ctio.noirlab.edu/soar/sites/default/files/GOODMAN/Hamuy/feige110_spec.pdf
[72] http://www.ctio.noirlab.edu/soar/sites/default/files/GOODMAN/Hamuy/ltt9491_dss.pdf
[73] http://www.ctio.noirlab.edu/soar/sites/default/files/GOODMAN/Hamuy/ltt9491_spec.pdf
[74] https://ui.adsabs.harvard.edu/?#abs/2013A%26A...552A..64S
[75] http://vizier.u-strasbg.fr/viz-bin/VizieR-3?-source=J/A%2bA/552/A64/table4