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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').
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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.

Advanced Search Examples (click to copy):

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

21770 results found.

  1. GRB040929,optical observation
  2. GRB040924,optical observation
  3. GRB040924,optical observation
  4. GRB040924: KAIT observations
  5. GRB 040924: Subaru NIR observation
  6. GRB 040924, optical follow-up
  7. GRB040912(=H3557): Chandra Candidate X-ray Afterglow
  8. XRF040916: continuing decay of OT
  9. TAROT Observations of GRB 040916 (HETE #3558)
  10. GRB040912(=H3557): Candidate Optical Afterglow
  11. XRF040916, optical observations
  12. XRF 040912, identification of CXO sources
  13. XRF 040912 (=H3557): Spectral and Temporal Properties
  14. XRF040912, BVRcIc field calibration
  15. XRF040916, BVRcIc field calibration
  16. GRB040912(=H3557): Observations with the Chandra X-ray Observatory
  17. GRB040916: Optical observations
  18. GRB 040912: Optical Observations
  19. GRB/XRF040912,optical observations
  20. GRB 040912, BVRI observations
  21. An intense burst from SGR1806-20
  22. GRB040912 : Kiso Optical follow-up observation
  23. Optical observations of field of GRB040912
  24. HETE 3557: Optical observations
  25. GRB040903 - A XRF?
  26. GRB040827: analysis of the XMM-Newton observation
  27. GRB040903, REM near-IR observation
  28. Very bright burst detected from SGR 1806-20
  29. ROTSE-III Rapid Response to possible GRB 040903 (INTEGRAL #1972)
  30. GRB 040827 - Radio Observations
  31. XMM-Newton Images of GRB 040827
  32. GRB 040827: optical and NIR observations at the VLT
  33. GRB 040827: RTT150 optical observations
  34. GRB040827 XMM-Newton observation
  35. MASTER: GRB040827 possible OT
  36. GRB 040825B: Optical observations
  37. GRB 040827 : Planned XMM-Newton observation
  38. GRB 040827 - Refined position
  39. GRB040825B, BVRcIc field photometry
  40. GRB040825A, BVRcIc field photometry
  41. GCN GRB OBSERBATION REPORT
  42. GRB 040825A,optical observations
  43. Increase of SGR 1806-20 activity
  44. GRB040825A: optical observations
  45. GRB040825B: optical observations
  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. CXO observation of GRB 040812
  52. GRB040812, optical/IR observations
  53. Konus-Wind observation of GRB040810 (=H3489)
  54. XRF040701: Optical Observations at ESO
  55. GRB 040730, infrared observations
  56. Ongoing activity of SGR 1806-20
  57. GRB040624: optical monitoring at TNG
  58. XRF 040701 - optical observations of the decaying Chandra source
  59. XRF040701: Second-Epoch Chandra Observations
  60. XRF040701: VLA Observations
  61. XRF040701: First-Epoch Chandra Observations
  62. GRB040624, optical observations
  63. GRB040706:observation at University of Miyazaki
  64. Optical Observations of GRB040624
  65. GRB 040624: optical observations at TNG and VLT
  66. MASTER: GRB 040624 optical observation after 0,48d
  67. GRB 040624, optical observations
  68. GRB 030329: Rebrightening of hyperluminal ejecta.
  69. IPN Summary of SGR1806-20 Activity in 2004
  70. SGR 1806-20: no IR variability of the proposed counterparts
  71. MASTER:HETE Alert 3259 (SRG1806-20) optical observation
  72. GRB 040606: Optical observations
  73. MASTER: HETE Alert 3274 optical observation
  74. Activivty of SGR 1806-20
  75. IPN triangulation of an intense intermediate burst from SGR1806-20
  76. GRB 040511, very fast decay?
  77. GRB 030324: Detection and Color of Host Galaxy
  78. GRB 040511: NIR observations with REM
  79. GRB040511: Candidate optical/NIR afterglow
  80. GRB 040511: ROTSE-III Rapid Optical Upper Limits
  81. GRB 040511: Second Epoch Optical Observations
  82. GRB 040511: Optical observations
  83. GRB 040511: Optical Observations
  84. GRB040511: Optical Observations
  85. GRB040511: Optical Observations
  86. GRB040511 (=H3218): A Long GRB Localized by HETE WXM and SXC
  87. GRB 040423 (=H3175): A Long GRB Localized by HETE
  88. GRB040422 : I-band follow-up observation at Lulin Observatory
  89. GRB 040422: ROTSE-IIIb Prompt Optical Limits
  90. GRB040422, BVRcIc field calibration
  91. GRB 040422,optical observation
  92. GRB 040403, deep optical observations
  93. MASTER: HETE Alert 3163, 3167 technical optical observation
  94. HETE/IPN localization of GRB040403A (=H3143, a long burst) and GRB040403B(=H3144, a short/hard burst)
  95. GRB 040403: Optical observations
  96. GRB 040329: hard burst detected by Konus-Wind and Helicon - Coronas-F
  97. GRB040323: NIR Observations and Variable Object
  98. GRB 040323, a dark GRB ?
  99. short hard GRB 040322
  100. GRB040223, improved XMM position

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