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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"

28040 results found.

  1. XRF 040912: Radio Observations
  2. XRF 040916: Radio Observations
  3. GRB040912(=H3557): Chandra Candidate X-ray Afterglow
  4. XRF040916: continuing decay of OT
  5. TAROT Observations of GRB 040916 (HETE #3558)
  6. GRB040912(=H3557): Candidate Optical Afterglow
  7. XRF040916, optical observations
  8. XRF 040912, identification of CXO sources
  9. XRF040912, BVRcIc field calibration
  10. XRF040916, BVRcIc field calibration
  11. GRB040916: Archival optical observations
  12. GRB040912(=H3557): Observations with the Chandra X-ray Observatory
  13. GRB040916: Optical observations
  14. GRB040912 (= H3557): Chandra Observations Scheduled
  15. GRB 040912: Optical Observations
  16. GRB/XRF040912,optical observations
  17. GRB 040912, BVRI observations
  18. Optical observations of field of GRB040912
  19. HETE 3557: Optical observations
  20. GRB040903 - A XRF?
  21. GRB040827: analysis of the XMM-Newton observation
  22. GRB040903, REM near-IR observation
  23. Very bright burst detected from SGR 1806-20
  24. ROTSE-III Rapid Response to possible GRB 040903 (INTEGRAL #1972)
  25. Possible GRB 040903 - further analysis
  26. GRB 040827 - Radio Observations
  27. XMM-Newton Images of GRB 040827
  28. GRB 040827: optical and NIR observations at the VLT
  29. GRB 040827: UKIRT - 2nd epoch K-band imaging
  30. GRB 040827: 2nd epoch of Magellan K-band imaging
  31. GRB 040827: K imaging - no evidence of variability
  32. GRB 040827: Detection of NIR afterglow
  33. GRB040827 XMM-Newton observation
  34. GRB040825A: optical limit before GRB
  35. GRB 040825B: Optical observations
  36. GRB 040827 : Planned XMM-Newton observation
  37. GRB040825B, BVRcIc field photometry
  38. GRB040825A, BVRcIc field photometry
  39. GCN GRB OBSERBATION REPORT
  40. GRB 040825A,optical observations
  41. GRB040825A: optical observations
  42. GRB040825B: optical observations
  43. MASTER: GRB040825b optical observation
  44. GRB 040825: Optical observations
  45. XRF040812: possible afterglow second Chandra observation
  46. GRB 040812: Second epoch CXO Observations
  47. GRB040823,optical observation
  48. XRF040812: GMRT observations
  49. XRF 040812: optical observation at VLT
  50. GRB 040812: Optical counterparts of CXO sources
  51. XRF040812: possible afterglow
  52. CXO observation of GRB 040812
  53. GRB 040812: radio observations
  54. GRB040812, optical/IR observations
  55. GRB 040812: a long GRB detected by INTEGRAL
  56. XRF040701: Optical Observations at ESO
  57. GRB 040730, infrared observations
  58. GRB 040730: a long GRB detected with INTEGRAL
  59. Ongoing activity of SGR 1806-20
  60. GRB040624: optical monitoring at TNG
  61. XRF 040701 - optical observations of the decaying Chandra source
  62. XRF040701: Second-Epoch Chandra Observations
  63. XRF040701: VLA Observations
  64. XRF040701: First-Epoch Chandra Observations
  65. GRB040624, optical observations
  66. GRB040706:observation at University of Miyazaki
  67. Optical Observations of GRB040624
  68. GRB 040624: optical observations at TNG and VLT
  69. MASTER: GRB 040624 optical observation after 0,48d
  70. GRB 040624, optical observations
  71. GRB 040624 - A long GRB detected with INTEGRAL
  72. GRB 030329: Rebrightening of hyperluminal ejecta.
  73. IPN Summary of SGR1806-20 Activity in 2004
  74. SGR 1806-20: no IR variability of the proposed counterparts
  75. MASTER:HETE Alert 3259 (SRG1806-20) optical observation
  76. SGR 1806-20, potential NIR counterpart
  77. GRB 040606: Optical observations
  78. MASTER: HETE Alert 3274 optical observation
  79. Activivty of SGR 1806-20
  80. GRB 040511, very fast decay?
  81. GRB 030324: Detection and Color of Host Galaxy
  82. GRB 040511: NIR observations with REM
  83. GRB040511: Candidate optical/NIR afterglow
  84. GRB 040511: ROTSE-III Rapid Optical Upper Limits
  85. GRB 040511: Second Epoch Optical Observations
  86. GRB 040511: Optical observations
  87. GRB 040511: Optical Observations
  88. GRB040511: Optical Observations
  89. GRB040511: Optical Observations
  90. Type Ic SN2001em (off-axis GRB jet?), optical spectrum
  91. GRB 040423 (=H3175): A Long GRB Localized by HETE
  92. GRB040422 : I-band follow-up observation at Lulin Observatory
  93. GRB 040422: ROTSE-IIIb Prompt Optical Limits
  94. GRB040422, BVRcIc field calibration
  95. GRB 040422,optical observation
  96. GRB 040422: a long GRB detected with INTEGRAL
  97. GRB 040403, deep optical observations
  98. MASTER: HETE Alert 3163, 3167 technical optical observation
  99. HETE/IPN localization of GRB040403A (=H3143, a long burst) and GRB040403B(=H3144, a short/hard burst)
  100. GRB 040403: Optical observations

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