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GCN Circulars

GCN Circulars are rapid astronomical bulletins submitted by and distributed to community members worldwide. They are used to share discoveries, observations, quantitative near-term predictions, requests for follow-up observations, or future observing plans related to high-energy, multi-messenger, and variable or transient astrophysical events. See the documentation for help with subscribing to or submitting Circulars.

Search for Circulars by submitter, subject, or body text (e.g. 'Fermi GRB').
To navigate to a specific circular, enter the associated Circular ID (e.g. 'gcn123', 'Circular 123', or '123').
Advanced Search

To narrow the search results, use advanced search syntax. This allows for specifying which circular field to search (submitter, subject, and/or body). For additional information, refer to the advanced search documentation.

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subject:"Swift"
body:"GRB"
submitter:"Judith Racusin"

24671 results found.

  1. GRB 040624, optical observations
  2. GRB 040624 - A long GRB detected with INTEGRAL
  3. GRB 030329: Rebrightening of hyperluminal ejecta.
  4. IPN Summary of SGR1806-20 Activity in 2004
  5. SGR 1806-20: no IR variability of the proposed counterparts
  6. MASTER:HETE Alert 3259 (SRG1806-20) optical observation
  7. SGR 1806-20, potential NIR counterpart
  8. GRB 040606: Optical observations
  9. MASTER: HETE Alert 3274 optical observation
  10. Activivty of SGR 1806-20
  11. GRB 040511, very fast decay?
  12. GRB 030324: Detection and Color of Host Galaxy
  13. GRB 040511: NIR observations with REM
  14. GRB040511: Candidate optical/NIR afterglow
  15. GRB 040511: ROTSE-III Rapid Optical Upper Limits
  16. GRB 040511: Second Epoch Optical Observations
  17. GRB 040511: Optical observations
  18. GRB 040511: Optical Observations
  19. GRB040511: Optical Observations
  20. GRB040511: Optical Observations
  21. Type Ic SN2001em (off-axis GRB jet?), optical spectrum
  22. GRB 040423 (=H3175): A Long GRB Localized by HETE
  23. GRB040422 : I-band follow-up observation at Lulin Observatory
  24. GRB 040422: ROTSE-IIIb Prompt Optical Limits
  25. GRB040422, BVRcIc field calibration
  26. GRB 040422,optical observation
  27. GRB 040422: a long GRB detected with INTEGRAL
  28. GRB 040403, deep optical observations
  29. MASTER: HETE Alert 3163, 3167 technical optical observation
  30. HETE/IPN localization of GRB040403A (=H3143, a long burst) and GRB040403B(=H3144, a short/hard burst)
  31. GRB 040403: Optical observations
  32. GRB 040403: a long GRB detected with INTEGRAL
  33. GRB040323: NIR Observations and Variable Object
  34. GRB 040319 (=H3128): An X-Ray-Rich GRB Localized by the HETE-2 WXM and SXC
  35. GRB 040323, a dark GRB ?
  36. GRB 040323: a long GRB detected with INTEGRAL
  37. GRB040223: Deep NIR NTT data re-analysis
  38. GRB 040223: XMM-Newton results
  39. GRB040223, improved XMM position
  40. GRB 031203, possible supernova
  41. MASTER: RXTE GRB040308 optical observation
  42. IBAS results on a burst from SGR1806-20
  43. INTEGRAL detection of activity from SGR1806-20
  44. RXTE GRB040229 optical observation: no candidate
  45. GRB 040228 Optical observations
  46. GRB040228 : KISO optical follow-up observation
  47. GRB 040223: Deep NIR NTT observations
  48. GRB 040223 : Optical observation (non-detection)
  49. XMM-Newton Images of GRB 040223
  50. GRB 040223, VLA observations
  51. GRB 040223: REM IJK Observations
  52. GRB 040223 XMM-Newton observation ...
  53. GRB 031203 XMM-Newton observation
  54. GRB 040223: further offline analysis
  55. GRB031111, optical observations
  56. GRB031220: 2nd Chandra observation and X-ray afterglow candidate
  57. GRB031203: Chandra Observations
  58. GRB040106: refined X-ray transient position
  59. SN 2003dh/GRB030329 late-time optical spectroscopy
  60. GRB 031220: Optical observations of Chandra X-ray sources
  61. XMM-Newton Images of GRB 040106
  62. GRB031220: observation at Univercity of Miyazaki
  63. XMM-Newton observation of GRB040106
  64. GRB 040106 : peak flux
  65. GRB031220(=H2976): TNG R-band Observation of the Chandra X-ray Sources
  66. GRB031220(=H2976): Observation with the Chandra X-ray Observatory
  67. GRB031220: Palomar Observations
  68. GRB 031220 : Kyoto Optical Observation
  69. GRB 031220: Subaru observation
  70. GRB 031220: Optical observation at Tokyo Tech
  71. GRB 2974 follow-up observations
  72. GRB031203, improved XMM position
  73. GRB 021203: A Normal GRB viewed far off axis?
  74. XMM-Newton Observations of GRB031203: Preliminary Images
  75. GRB 031203: Variable Radio Source
  76. GRB 031203: Magellan spectrum of possible GRB host
  77. GRB 031203: Optical/IR Astrometry
  78. GRB031203: ROSAT upper limits suggest XMM-S1 source as the transient
  79. XMM-Newton Observation of GRB031203
  80. GRB031203: K' Photometry of the likely GRB host
  81. XMM-Newton Observation of GRB031203
  82. GRB 031203: IR NTTobservations do not confirm REM detection
  83. GRB031203 : Optical Observation of Lulin Observatory
  84. GRB 031203: z ~ 10 or Fragmented Dust in the Circumburst Environment?
  85. GRB 031203: Apparent Spectral Break
  86. GRB031203: Planned XMM-Newton observation II
  87. GRB 031203: IR REM Observations
  88. GRB031203: Optical Observations
  89. GRB 031203 XMM-Newton observation
  90. GRB031203: Planned XMM-Newton observation
  91. GRB 031203: further analysis of INTEGRAL data
  92. GRB 030329: Planned XMM-Newton Observation
  93. GRB 031111B (= H2925) : Kyoto Optical Observation
  94. IPN triangulation of GRB031114 (large error box)
  95. GRB 031111, optical observations
  96. GRB031026: 1.2mm upper limit with MAMBO at the IRAM 30m
  97. GRB030929/SN2003jd association unlikely based on IPN localiztion
  98. IPN triangulation of GRB031027 (small error box)
  99. Lulin optical follow-up observations of GRB031026
  100. GRB 031026 (=H2882): Evidence for High Redshift from Prompt

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