GRB 200803A
GCN Circular 28196
Subject
GRB 200803A: Fermi GBM Final Real-time Localization
Date
2020-08-03T03:44:43Z (5 years ago)
From
Fermi GBM Team at MSFC/Fermi-GBM <do_not_reply@GIOC.nsstc.nasa.gov>
The Fermi GBM team reports the detection of a likely LONG GRB
At 03:34:26 UT on 3 Aug 2020, the Fermi Gamma-ray Burst Monitor (GBM) triggered and located GRB 200803A (trigger 618118471.567908 / 200803149).
The on-ground calculated location, using the Fermi GBM trigger data, is RA = 313.6, Dec = -62.0 (J2000 degrees, equivalent to J2000 20h 54m, -62d 00'), with a statistical uncertainty of 1.4 degrees.
The angle from the Fermi LAT boresight is 39.0 degrees.
The skymap can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2020/bn200803149/quicklook/glg_skymap_all_bn200803149.png
The HEALPix FITS file, including the estimated localization systematic, can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2020/bn200803149/quicklook/glg_healpix_all_bn200803149.fit
The GBM light curve can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2020/bn200803149/quicklook/glg_lc_medres34_bn200803149.gif
GCN Circular 28198
Subject
Fermi GRB 200803A: Global MASTER-Net observations report
Date
2020-08-03T05:30:08Z (5 years ago)
From
Vladimir Lipunov at Moscow State U/Krylov Obs <lipunov@xray.sai.msu.ru>
V. Lipunov, E. Gorbovskoy, V.Kornilov, N.Tyurina, P.Balanutsa, A.Kuznetsov, F.Balakin,
V.Vladimirov, D. Vlasenko, I.Gorbunov, D.Zimnukhov, V.Senik, T.Pogrosheva,
D.Kuvshinov, D. Cheryasov
(Lomonosov Moscow State University, SAI, Physics Department),
R. Podesta, C.Lopez, F. Podesta, C.Francile
(Observatorio Astronomico Felix Aguilar OAFA),
H.Levato
(Instituto de Ciencias Astronomicas, de la Tierra y del Espacio ICATE),
R. Rebolo, M. Serra
(The Instituto de Astrofisica de Canarias),
D. Buckley
(South African Astronomical Observatory),
O.A. Gres, N.M. Budnev, O.Ershova
(Irkutsk State University, API),
A. Tlatov, D. Dormidontov
(Kislovodsk Solar Station of the Pulkovo Observatory),
V. Yurkov, A. Gabovich, Yu. Sergienko
(Blagoveschensk Educational State University)
MASTER-SAAO robotic telescope (Global MASTER-Net: http://observ.pereplet.ru, Lipunov et al., 2010, Advances in Astronomy, vol. 2010, 30L) located in South Africa (South African Astronomical Observatory) started inspect of the Fermi GRB 200803A ( Fermi GBM team, GCN 28196) errorbox 47 sec after notice time and 74 sec after trigger time at 2020-08-03 03:35:40 UT, with upper limit up to 18.4 mag. The observations began at zenith distance = 50 deg. The sun altitude is -23.6 deg.
The galactic latitude b = -37 deg., longitude l = 330 deg.
Real time updated cover map and OT discovered available here:
https://master.sai.msu.ru/site/master2/observ.php?id=1412844
We obtain a following upper limits.
Tmid-T0 | Date Time | Site | Coord (J2000) |Filt.| Expt. | Limit| Comment
_________|_____________________|_____________________|____________________________________|_____|_______|_______|________
79 | 2020-08-03 03:35:40 | MASTER-SAAO | (21h 32m 06.21s , -63d 47m 40.4s) | C | 10 | 17.1 |
79 | 2020-08-03 03:35:40 | MASTER-SAAO | (21h 16m 08.66s , -63d 48m 22.1s) | C | 10 | 17.0 |
117 | 2020-08-03 03:36:13 | MASTER-SAAO | (20h 58m 19.87s , -62d 07m 21.8s) | C | 20 | 17.4 |
117 | 2020-08-03 03:36:13 | MASTER-SAAO | (20h 43m 15.94s , -62d 08m 01.9s) | C | 20 | 17.3 |
161 | 2020-08-03 03:36:52 | MASTER-SAAO | (20h 58m 19.46s , -62d 06m 21.5s) | C | 30 | 17.7 |
161 | 2020-08-03 03:36:53 | MASTER-SAAO | (20h 43m 16.07s , -62d 07m 01.3s) | C | 30 | 17.5 |
216 | 2020-08-03 03:37:42 | MASTER-SAAO | (20h 58m 25.16s , -62d 07m 20.7s) | C | 40 | 17.7 |
216 | 2020-08-03 03:37:42 | MASTER-SAAO | (20h 43m 21.25s , -62d 08m 01.0s) | C | 40 | 17.7 |
281 | 2020-08-03 03:38:42 | MASTER-SAAO | (20h 58m 18.78s , -62d 08m 20.2s) | C | 50 | 17.3 |
281 | 2020-08-03 03:38:42 | MASTER-SAAO | (20h 43m 14.45s , -62d 09m 00.3s) | C | 50 | 17.4 |
355 | 2020-08-03 03:39:51 | MASTER-SAAO | (20h 58m 23.73s , -62d 08m 19.8s) | C | 60 | 18.0 |
355 | 2020-08-03 03:39:51 | MASTER-SAAO | (20h 43m 19.42s , -62d 08m 59.6s) | C | 60 | 17.8 |
639 | 2020-08-03 03:44:05 | MASTER-SAAO | (20h 59m 38.80s , -62d 04m 25.4s) | C | 120 | 18.4 |
639 | 2020-08-03 03:44:05 | MASTER-SAAO | (20h 44m 36.50s , -62d 05m 05.2s) | C | 120 | 18.1 |
788 | 2020-08-03 03:46:24 | MASTER-SAAO | (20h 59m 38.20s , -62d 03m 23.4s) | C | 140 | 18.2 |
788 | 2020-08-03 03:46:24 | MASTER-SAAO | (20h 44m 36.56s , -62d 04m 02.7s) | C | 140 | 18.1 |
963 | 2020-08-03 03:49:04 | MASTER-SAAO | (20h 59m 44.87s , -62d 04m 22.3s) | C | 170 | 18.3 |
963 | 2020-08-03 03:49:04 | MASTER-SAAO | (20h 44m 42.77s , -62d 05m 01.8s) | C | 170 | 18.1 |
1157 | 2020-08-03 03:52:14 | MASTER-SAAO | (20h 59m 38.04s , -62d 05m 21.5s) | C | 180 | 18.4 |
1157 | 2020-08-03 03:52:14 | MASTER-SAAO | (20h 44m 35.46s , -62d 06m 00.8s) | C | 180 | 18.2 |
1357 | 2020-08-03 03:55:33 | MASTER-SAAO | (20h 59m 42.62s , -62d 05m 06.0s) | C | 180 | 18.3 |
1357 | 2020-08-03 03:55:33 | MASTER-SAAO | (20h 44m 40.17s , -62d 05m 44.4s) | C | 180 | 18.2 |
1556 | 2020-08-03 03:58:52 | MASTER-SAAO | (20h 59m 39.66s , -62d 03m 31.5s) | C | 180 | 18.2 |
1556 | 2020-08-03 03:58:52 | MASTER-SAAO | (20h 44m 38.10s , -62d 04m 09.5s) | C | 180 | 18.1 |
1756 | 2020-08-03 04:02:12 | MASTER-SAAO | (20h 59m 39.41s , -62d 05m 01.5s) | C | 180 | 18.2 |
1756 | 2020-08-03 04:02:12 | MASTER-SAAO | (20h 44m 37.33s , -62d 05m 39.6s) | C | 180 | 18.1 |
1895 | 2020-08-03 04:05:32 | MASTER-SAAO | (20h 46m 24.22s , -64d 02m 24.8s) | C | 60 | 18.1 |
1895 | 2020-08-03 04:05:32 | MASTER-SAAO | (20h 30m 19.82s , -64d 02m 58.5s) | C | 60 | 18.0 |
2147 | 2020-08-03 04:09:43 | MASTER-SAAO | (21h 06m 07.28s , -62d 03m 57.9s) | C | 60 | 18.0 |
2147 | 2020-08-03 04:09:43 | MASTER-SAAO | (20h 51m 06.05s , -62d 04m 36.1s) | C | 60 | 17.7 |
2227 | 2020-08-03 04:11:03 | MASTER-SAAO | (20h 46m 17.65s , -64d 04m 27.7s) | C | 60 | 18.0 |
2227 | 2020-08-03 04:11:03 | MASTER-SAAO | (20h 30m 12.34s , -64d 05m 00.7s) | C | 60 | 17.9 |
2307 | 2020-08-03 04:12:23 | MASTER-SAAO | (21h 23m 04.83s , -64d 05m 11.2s) | C | 60 | 18.1 |
2307 | 2020-08-03 04:12:23 | MASTER-SAAO | (21h 06m 58.62s , -64d 05m 49.1s) | C | 60 | 17.9 |
2386 | 2020-08-03 04:13:42 | MASTER-SAAO | (20h 31m 48.01s , -62d 02m 08.5s) | C | 60 | 17.8 |
2386 | 2020-08-03 04:13:42 | MASTER-SAAO | (20h 16m 48.47s , -62d 02m 41.6s) | C | 60 | 17.7 |
2466 | 2020-08-03 04:15:02 | MASTER-SAAO | (21h 04m 46.12s , -66d 04m 21.7s) | C | 60 | 17.9 |
2466 | 2020-08-03 04:15:02 | MASTER-SAAO | (20h 47m 25.31s , -66d 04m 53.5s) | C | 60 | 17.9 |
2546 | 2020-08-03 04:16:22 | MASTER-SAAO | (21h 12m 34.17s , -58d 03m 28.1s) | C | 60 | 17.7 |
2546 | 2020-08-03 04:16:22 | MASTER-SAAO | (20h 59m 16.32s , -58d 04m 09.5s) | C | 60 | 17.5 |
2626 | 2020-08-03 04:17:42 | MASTER-SAAO | (21h 22m 58.71s , -64d 04m 09.6s) | C | 60 | 17.9 |
2626 | 2020-08-03 04:17:42 | MASTER-SAAO | (21h 06m 53.08s , -64d 04m 46.3s) | C | 60 | 17.7 |
2706 | 2020-08-03 04:19:02 | MASTER-SAAO | (20h 31m 44.41s , -62d 02m 04.4s) | C | 60 | 17.8 |
2706 | 2020-08-03 04:19:02 | MASTER-SAAO | (20h 16m 44.79s , -62d 02m 36.9s) | C | 60 | 17.7 |
2785 | 2020-08-03 04:20:21 | MASTER-SAAO | (21h 04m 49.16s , -66d 03m 46.7s) | C | 60 | 18.0 |
2785 | 2020-08-03 04:20:21 | MASTER-SAAO | (20h 47m 28.61s , -66d 04m 17.9s) | C | 60 | 18.0 |
3125 | 2020-08-03 04:26:01 | MASTER-SAAO | (21h 12m 27.15s , -58d 04m 47.1s) | C | 60 | 17.5 |
3125 | 2020-08-03 04:26:01 | MASTER-SAAO | (20h 59m 21.24s , -58d 05m 36.2s) | C | 60 | 17.3 |
3374 | 2020-08-03 04:30:10 | MASTER-SAAO | (21h 40m 16.15s , -62d 03m 51.9s) | C | 60 | 17.4 |
3374 | 2020-08-03 04:30:10 | MASTER-SAAO | (21h 25m 21.18s , -62d 04m 45.3s) | C | 60 | 17.2 |
3454 | 2020-08-03 04:31:30 | MASTER-SAAO | (20h 25m 05.24s , -66d 02m 51.4s) | C | 60 | 17.2 |
3454 | 2020-08-03 04:31:30 | MASTER-SAAO | (20h 07m 53.31s , -66d 03m 26.9s) | C | 60 | 17.1 |
3709 | 2020-08-03 04:35:45 | MASTER-SAAO | (21h 40m 10.66s , -62d 05m 20.6s) | C | 60 | 16.8 |
3709 | 2020-08-03 04:35:45 | MASTER-SAAO | (21h 25m 14.14s , -62d 06m 15.2s) | C | 60 | 16.9 |
3789 | 2020-08-03 04:37:05 | MASTER-SAAO | (20h 25m 09.83s , -66d 03m 27.2s) | C | 60 | 16.7 |
3789 | 2020-08-03 04:37:05 | MASTER-SAAO | (20h 07m 57.18s , -66d 04m 03.3s) | C | 60 | 16.6 |
Filter C is a clear (unfiltred) band.
The observation and reduction will continue.
The message may be cited.
GCN Circular 28200
Subject
GRB 200803A: Tiled Swift observations
Date
2020-08-03T13:40:05Z (5 years ago)
From
Phil Evans at U of Leicester <pae9@leicester.ac.uk>
P. A. Evans (U. Leicester) reports on behalf of the Swift team:
Swift has initiated a series of observations, tiled on the sky, of the
Fermi/LAT GRB 200803A. Automated analysis of the XRT data will
be presented online at http://www.swift.ac.uk/xrt_products/TILED_GRB00092
Any uncatalogued X-ray sources detected in this analysis will be
reported on this website and via GCN COUNTERPART notices. The probability of finding
serendipitous sources, unrelated to the Fermi/LAT event is high: any X-ray source
considered to be a probable afterglow candidate will be reported via a GCN Circular
after manual consideration.
Details of the XRT automated analysis methods are detailed in Evans et
al. (2007, A&A, 469, 379; 2009, MNRAS, 397, 1177 and 2014, ApJS, 210, 8).
This circular is an official product of the Swift-XRT team.
GCN Circular 28202
Subject
GRB 200803A: MASTER optical counterpart discovery
Date
2020-08-03T17:12:31Z (5 years ago)
From
Vladimir Lipunov at Moscow State U/Krylov Obs <lipunov@xray.sai.msu.ru>
V. Lipunov, E. Gorbovskoy, V.Kornilov, N.Tyurina,
P.Balanutsa,A.Kuznetsov,F.Balakin,
V.Vladimirov, D. Vlasenko, I.Gorbunov, D.Zimnukhov, V.Senik, T.Pogrosheva,
D.Kuvshinov(Lomonosov Moscow State University, SAI, Physics Department),
A. Tlatov, D. Dormidontov (Kislovodsk Solar Station of the Pulkovo Observatory),
R. Podesta, C.Lopez, F. Podesta, C.Francile(Observatorio Astronomico Felix
Aguilar OAFA),
H.Levato(Instituto de Ciencias Astronomicas, de la Tierra y del Espacio ICATE),
R. Rebolo, M. Serra(The Instituto de Astrofisica de Canarias),
D. Buckley(South African Astronomical Observatory),
O.A. Gres, N.M. Budnev, O.Ershova (Irkutsk State University, API),
V. Yurkov, A. Gabovich, Yu. Sergienko(Blagoveschensk Educational StateUniversity)
MASTER Global Robotic Net inspected GRB 200803A
(MASTER Lipunov et al. GCN 28198, Fermi LAT GCN 28199)
The result is optical counterpart discovery with classical OT decay
MASTER OT J204422.34-625641.8 discovery
MASTER-SAAO auto-detection system ( Lipunov et al., "MASTER Global Robotic
Net", Advances in Astronomy, 2010, 30L ) discovered OT source at
(RA, Dec) = 20h 44m 22.34s -62d 56m 41.8s on 2020-08-03.15015 UT.
The OT unfiltered magnitude is 15.8m (mlim=17.7).
The OT is seen in 13 images. There is no minor planet at this place.
We have reference image on 2015-04-04.15164 UT with unfiltered mlim= 19.9m.
Spectral observations are required.
GCN Circular 28203
Subject
GRB 200803A: Fermi-LAT detection
Date
2020-08-03T17:37:42Z (5 years ago)
From
Sara Cutini at INFN <sara.cutini@pg.infn.it>
S. Cutini (INFN Perugia), F. Longo (University & INFN Trieste),
M. Axelsson (KTH & StockholmUniv.), M. Ohno (Hiroshima Univ. & Eotvos Univ.),
F. Dirirsa (Univ. of Johannesburg), D.Kocesvki (NASA/MSFC), and N. Omodei (Stanford U.),
report on behalf of the Fermi-LAT team:
At 03:34:26.57 on August, 03, 2020 Fermi-LAT detected high-energy emission from GRB 200803A,
which was also detected by Fermi-GBM (GCN 28196).
The best LAT on-ground location is found to be
RA, Dec = 311.29, -63.08 (J2000)
with an error radius of 0.46 deg (90 % containment, statistical error only).
This was 39 deg from the LAT boresight at the time of the trigger,
the Fermi-LAT entered in the SAA at around 450 seconds after the trigger.
The data from the Fermi-LAT show a significant increase in the event rate
that is spatially and temporally correlated with the trigger with high significance.
The photon flux above 100 MeV in the time interval 0-450 s after the GBM trigger is 8.0e-6 +/- 2.3e-6 ph/cm2/s.
The estimated photon index above 100 MeV is -2.4+/-0.3.
The highest-energy photon is ~650 MeV event which is observed ~200 seconds after the GBM trigger.
A Swift ToO has been approved for this burst.
The Fermi-LAT point of contact for this burst is Sara Cutini (sara.cutini@pg.infn.it)
The Fermi-LAT is a pair conversion telescope designed to cover the energy band from 20 MeV to greater than 300 GeV.
It is the product of an international collaboration between NASA and DOE in the U.S. and many scientific institutions across France, Italy, Japan and Sweden.
GCN Circular 28205
Subject
GRB 200803A: Swift-XRT afterglow detection
Date
2020-08-03T20:28:04Z (5 years ago)
From
Andy Beardmore at U Leicester <ab271@leicester.ac.uk>
J.P. Osborne (U. Leicester), K.L. Page (U. Leicester), M.G. Bernardini
(INAF-OAB), E. Ambrosi (INAF-IASFPA) , M. Capalbi (INAF-IASFPA), B.
Sbarufatti (PSU), D.N. Burrows (PSU), J. D. Gropp (PSU) and P.A. Evans
(U. Leicester) report on behalf of the Swift-XRT team:
Swift-XRT has performed follow-up observations of the
Fermi/LAT-detected burst GRB 200803A (Cutini et al. GCN Circ. 28203) in
a series of observations tiled on the sky. The total exposure time is
3.5 ks, distributed over 4 tiles; the maximum exposure at a single sky
location was 1.6 ks. The data were collected between T0+36.3 ks and
T0+46.6 ks, and are entirely in Photon Counting (PC) mode.
Five uncatalogued X-ray sources are detected, of which one ("Source 1")
is above the RASS limit, and is therefore likely the GRB afterglow.
Using 812 s of PC mode data and 2 UVOT images, we find an enhanced XRT
position (using the XRT-UVOT alignment and matching UVOT field sources
to the USNO-B1 catalogue): RA, Dec = 311.09390, -62.94478 which is
equivalent to:
RA (J2000): 20h 44m 22.54s
Dec(J2000): -62d 56' 41.2"
with an uncertainty of 2.8 arcsec (radius, 90% confidence). This
position is 9.7 arcmin from the Fermi/LAT position and 1.5 arcsec from
the MASTER optical counterpart reported by Lipunov et al. (GCN Circ.
28202).
The light curve can be modelled with a power-law decay with a decay
index of alpha=3.30 (+0.06, -2.56).
If the light curve continues to decay with a power-law decay index of
3.30, the count rate at T+24 hours will be 2.1 x 10^-3 count s^-1
The results of the XRT-team automatic analysis of the likely afterglow
are at https://www.swift.ac.uk/xrt_products/TILED_GRB00092/Source1.php.
The results of the full analysis of the tiled XRT observations are
available at https://www.swift.ac.uk/xrt_products/TILED_GRB00092.
This circular is an official product of the Swift-XRT team.
GCN Circular 28206
Subject
GRB 200803A: Fermi GBM detection
Date
2020-08-03T22:22:25Z (5 years ago)
From
Rachel Hamburg at UAH <rkh0007@uah.edu>
R. Hamburg (UAH) and C. Meegan (UAH) report on behalf of the Fermi GBM Team:
"At 03:34:26.00 UT on 03 August 2020, the Fermi Gamma-Ray Burst Monitor
(GBM)
triggered and located GRB 200803A (trigger 618118471 / 200803149)
which was also detected by the Fermi/LAT (Cutini et al. 2020,
GCN 28203). The Fermi GBM Final Real-time Localization (GCN 28196) is
consistent with the LAT position. An x-ray afterglow candidate has
been detected by the Swift/XRT (GCN 28205), and a potential optical
counterpart has also been reported by MASTER (GCN 28202).
The angle from the Fermi LAT boresight at the GBM trigger time is ~39
degrees.
The GBM light curve consists of two main pulses
with a duration (T90) of about 119 s (50-300 keV).
The time-averaged spectrum of the first pulse, from T0-4 s to
T0+14 s is best fit by a power law function with an exponential
high-energy cutoff. The power law index is -0.67 +/- 0.04 and
the cutoff energy, parameterized as Epeak, is 302 +/- 13 keV.
The event fluence (10-1000 keV) in this time interval is
(1.12 +/- 0.03)E-05.
The time-averaged spectrum of the second pulse, from T0+85 s to
T0+118 s is also best fit by a power law function with an
exponential high-energy cutoff. The power law index is
-1.13 +/- 0.02 and the cutoff energy, parameterized as Epeak,
is 223 +/- 8 keV. The event fluence (10-1000 keV) in this time
interval is (1.84 +/- 0.03)E-05.
The 1-sec peak photon flux measured
starting from T0+112 s in the 10-1000 keV band
is 10.8 +/- 0.3 ph/s/cm^2.
The spectral analysis results presented above are preliminary;
final results will be published in the GBM GRB Catalog:
https://heasarc.gsfc.nasa.gov/W3Browse/fermi/fermigbrst.html
For Fermi GBM data and info, please visit the official Fermi GBM Support
Page:
https://fermi.gsfc.nasa.gov/ssc/data/access/gbm/"
GCN Circular 28207
Subject
GRB 200803A: AstroSat CZTI detection
Date
2020-08-04T12:43:55Z (5 years ago)
From
Soumya Gupta at IUCAA/ASTROSAT <soumya@iucaa>
S. Gupta, V. Sharma and D. Bhattacharya (IUCAA), V. Bhalerao (IIT-B), A. R. Rao (IUCAA/TIFR) and S. Vadawale (PRL) report on behalf of the AstroSat CZTI collaboration:
The AstroSat CZT Imager recorded a transient event in all four of its CsI anticoincidence (Veto) detectors in the 100-500 keV energy range, coincident with the GRB 200803A reported by Fermi GBM (GCN #28196), Global MASTER-Net (Lipunov V. et al., GCN #28198) Tiled Swift (Evans P. et al., GCN #29200), Fermi-LAT (Cutini S. et al., GCN #29203) and Swift-XRT (Osborne J. et al., GCN #29205). There was no significant detection in the main CZT detectors.
The light curve showed multiple peaks of emission with the strongest peak at 2020-08-03 03:34:34.825 UT. The measured peak count rate is 444 +/- 46 cts/s above the background in the combined Veto data of four quadrants, with a total of 2872 +/- 42 cts. The local mean background count rate was 1740 +/- 2 cts/s. We measure a T90 of 17.81 +/- 0.77 s from the cumulative Veto light curve.
CZTI GRB detections are reported regularly on the payload site at http://astrosat.iucaa.in/czti/?q=grb. CZTI is built by a TIFR-led consortium of institutes across India, including VSSC, ISAC, IUCAA, SAC and PRL. The Indian Space Research Organisation funded, managed and facilitated the project.
GCN Circular 28226
Subject
GRB 200803A: Chilescope optical upper limit
Date
2020-08-07T22:07:23Z (5 years ago)
From
Alexei Pozanenko at IKI, Moscow <apozanen@iki.rssi.ru>
S. Belkin (IKI), A. Pozanenko (IKI), M. Krugov (AFIF), A. Volnova
(IKI), E. Mazaeva (IKI) report on behalf of IKI-FuN follow-up collaboration:
We observed the GRB 200803A (Fermi GBM Team, GCN 28196; Hamburg et al.,
GCN 28206) with Chilescope RC-1000 starting on 2020-08-05 (UT) 03:53:45
in r'-filter. We did not detect optical afterglow (Lipunov et al., GCN
28202).
Preliminary photometry is following.
Date UT start t-T0 Filter Exp. OT Err. UL
(mid, days) (s)
2020-08-05 03:53:45 2.03425 r' 6*600 n/d n/d 21.5
The photometry is based on nearby USNO-B1.0 stars
Ref.stars
USNO-B1.0_id R2
0270-0863045 16.4
0270-0862955 15.5
0271-0884796 15.0