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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"

24886 results found.

  1. GRB 040812: a long GRB detected by INTEGRAL
  2. XRF040701: Optical Observations at ESO
  3. GRB 040730, infrared observations
  4. GRB 040730: a long GRB detected with INTEGRAL
  5. Ongoing activity of SGR 1806-20
  6. GRB040624: optical monitoring at TNG
  7. XRF 040701 - optical observations of the decaying Chandra source
  8. XRF040701: Second-Epoch Chandra Observations
  9. XRF040701: VLA Observations
  10. XRF040701: First-Epoch Chandra Observations
  11. GRB040624, optical observations
  12. GRB040706:observation at University of Miyazaki
  13. Optical Observations of GRB040624
  14. GRB 040624: optical observations at TNG and VLT
  15. MASTER: GRB 040624 optical observation after 0,48d
  16. GRB 040624, optical observations
  17. GRB 040624 - A long GRB detected with INTEGRAL
  18. GRB 030329: Rebrightening of hyperluminal ejecta.
  19. IPN Summary of SGR1806-20 Activity in 2004
  20. SGR 1806-20: no IR variability of the proposed counterparts
  21. MASTER:HETE Alert 3259 (SRG1806-20) optical observation
  22. SGR 1806-20, potential NIR counterpart
  23. GRB 040606: Optical observations
  24. MASTER: HETE Alert 3274 optical observation
  25. Activivty of SGR 1806-20
  26. GRB 040511, very fast decay?
  27. GRB 030324: Detection and Color of Host Galaxy
  28. GRB 040511: NIR observations with REM
  29. GRB040511: Candidate optical/NIR afterglow
  30. GRB 040511: ROTSE-III Rapid Optical Upper Limits
  31. GRB 040511: Second Epoch Optical Observations
  32. GRB 040511: Optical observations
  33. GRB 040511: Optical Observations
  34. GRB040511: Optical Observations
  35. GRB040511: Optical Observations
  36. Type Ic SN2001em (off-axis GRB jet?), optical spectrum
  37. GRB 040423 (=H3175): A Long GRB Localized by HETE
  38. GRB040422 : I-band follow-up observation at Lulin Observatory
  39. GRB 040422: ROTSE-IIIb Prompt Optical Limits
  40. GRB040422, BVRcIc field calibration
  41. GRB 040422,optical observation
  42. GRB 040422: a long GRB detected with INTEGRAL
  43. GRB 040403, deep optical observations
  44. MASTER: HETE Alert 3163, 3167 technical optical observation
  45. HETE/IPN localization of GRB040403A (=H3143, a long burst) and GRB040403B(=H3144, a short/hard burst)
  46. GRB 040403: Optical observations
  47. GRB 040403: a long GRB detected with INTEGRAL
  48. GRB040323: NIR Observations and Variable Object
  49. GRB 040319 (=H3128): An X-Ray-Rich GRB Localized by the HETE-2 WXM and SXC
  50. GRB 040323, a dark GRB ?
  51. GRB 040323: a long GRB detected with INTEGRAL
  52. GRB040223: Deep NIR NTT data re-analysis
  53. GRB 040223: XMM-Newton results
  54. GRB040223, improved XMM position
  55. GRB 031203, possible supernova
  56. MASTER: RXTE GRB040308 optical observation
  57. IBAS results on a burst from SGR1806-20
  58. INTEGRAL detection of activity from SGR1806-20
  59. RXTE GRB040229 optical observation: no candidate
  60. GRB 040228 Optical observations
  61. GRB040228 : KISO optical follow-up observation
  62. GRB 040223: Deep NIR NTT observations
  63. GRB 040223 : Optical observation (non-detection)
  64. XMM-Newton Images of GRB 040223
  65. GRB 040223, VLA observations
  66. GRB 040223: REM IJK Observations
  67. GRB 040223 XMM-Newton observation ...
  68. GRB 031203 XMM-Newton observation
  69. GRB 040223: further offline analysis
  70. GRB031111, optical observations
  71. GRB031220: 2nd Chandra observation and X-ray afterglow candidate
  72. GRB031203: Chandra Observations
  73. GRB040106: refined X-ray transient position
  74. SN 2003dh/GRB030329 late-time optical spectroscopy
  75. GRB 031220: Optical observations of Chandra X-ray sources
  76. XMM-Newton Images of GRB 040106
  77. GRB031220: observation at Univercity of Miyazaki
  78. XMM-Newton observation of GRB040106
  79. GRB 040106 : peak flux
  80. GRB031220(=H2976): TNG R-band Observation of the Chandra X-ray Sources
  81. GRB031220(=H2976): Observation with the Chandra X-ray Observatory
  82. GRB031220: Palomar Observations
  83. GRB 031220 : Kyoto Optical Observation
  84. GRB 031220: Subaru observation
  85. GRB 031220: Optical observation at Tokyo Tech
  86. GRB 2974 follow-up observations
  87. GRB031203, improved XMM position
  88. GRB 021203: A Normal GRB viewed far off axis?
  89. XMM-Newton Observations of GRB031203: Preliminary Images
  90. GRB 031203: Variable Radio Source
  91. GRB 031203: Magellan spectrum of possible GRB host
  92. GRB 031203: Optical/IR Astrometry
  93. GRB031203: ROSAT upper limits suggest XMM-S1 source as the transient
  94. XMM-Newton Observation of GRB031203
  95. GRB031203: K' Photometry of the likely GRB host
  96. XMM-Newton Observation of GRB031203
  97. GRB 031203: IR NTTobservations do not confirm REM detection
  98. GRB031203 : Optical Observation of Lulin Observatory
  99. GRB 031203: z ~ 10 or Fragmented Dust in the Circumburst Environment?
  100. GRB 031203: Apparent Spectral Break

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