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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.

Advanced Search Examples (click to copy):

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

2803 results found.

  1. IPN triangulation of GRB020923 (two error boxes)
  2. IPN annulus for GRB020923
  3. IPN triangulation of GRB020914B
  4. Improved IPN position for GRB020918 (two large error boxes)
  5. IPN annulus for GRB020914B
  6. IPN triangulation of GRB020911 (2 large error boxes)
  7. IPN triangulation of GRB020914 - clarification and additional information
  8. IPN triangulation of GRB020910
  9. IPN GCN Circulars now to be issued without restriction
  10. GRB 020813 : HST observations
  11. GRB020813: Magellan BVRI Photometry
  12. GRB020813: High-Resolution Optical Observations
  13. GRB020813: optical observations; possible host galaxy
  14. GRB020812: optical observations
  15. IPN triangulation of GRB020813
  16. GRB020812: possible afterglow candidate
  17. GRB020812: possible afterglow candidate
  18. GRB 020813 Afterglow Observations; Possible break
  19. GRB 020410: Discovery of Probable OT by HST
  20. IPN triangulation of GRB020706
  21. Gemini IR Detection of AXP 1E 2259+586 Post-Burst
  22. Fading Optical Source in the Field of GRB020531
  23. GRB 020531, simultaneous optical observations
  24. GRB020531 Optical observations with TAROT
  25. GRB020531 Optical observations with TAROT
  26. IPN triangulation of GRB020604
  27. Correction to IPN triangulation of GRB020603 (possible short/hard burst)
  28. IPN triangulation of GRB020603 (possible short/hard GRB)
  29. GRB 020531 optical observations with TAROT
  30. IPN detection of possible bursts from SGR1806-20
  31. GRB020427 BeppoSAX NFI Observation
  32. GRB020405: VLT observations of the OT environment
  33. GRB020405: predicted break
  34. April 11 BeppoSAX event (GRB020411) is likely not a GRB
  35. BeppoSAX ALERT: possible GRB020411
  36. GRB020406(?), optical observations
  37. GRB020410, optical observations
  38. BeppoSAX ALERT: possible GRB020410
  39. Fading Optical Afterglow and Possible Host Galaxy of GRB 020405
  40. GRB 020321, Radio Observations
  41. GRB020321: BeppoSAX/NFI Observations
  42. GRB 020317: Optical observations
  43. GRB 011121: HST Observations reveal an intermediate-time multicolor
  44. GRB011121, possible supernova association
  45. GRB020127: Further VLA Observations of Possible Counterparts
  46. GRB020127: Palomar and VLA Observations of Possible Counterparts
  47. GRB020127: Comparison of Chandra Epochs and Identification of Possible Counterparts
  48. SN 2002ap (SN/GRB?)
  49. Type Ib/c SN2002ap (SN/GRB?) Radio Observations
  50. VLT observations of GRB 020124: The fading optical/near-infrared afterglow
  51. GRB 020124 Optical Observations
  52. GRB optical counterpart candidate in GCN 1217 is M dwarf
  53. Possible optical counterpart to a GRB
  54. GRB011130 (=XRF011130): Scheduled Target of Opportunity
  55. GRB 011130: Magellan spectroscopy
  56. GRB011130, optical observations
  57. GRB 011121: J-band observations
  58. GRB 011121: HST Scheduled
  59. GRB011121: fainter still
  60. GRB011121: continued decay
  61. GRB011121: possible redshift, continued decay
  62. GRB011121: fading behavior
  63. GRB011121: possible optical counterpart
  64. GRB 011030 I-band Observation
  65. GRB 011030, WSRT radio observations
  66. BeppoSAX ALERT: Possible X-ray rich GRB011030
  67. GRB 010921: Possible supernova component
  68. GRB010921: Spectroscopy of the Host Galaxy
  69. GRB010923(=H1764): A Short Duration GRB Detected by HETE
  70. IPN triangulation of GRB010921 (=H1761)
  71. GCN and HETE status
  72. GRB010629: Optical Observations
  73. Possible burst from SGR1806-20
  74. IPN triangulation of GRB010613
  75. HETE Fully-Automated GCN Notices
  76. GRB010214, optical observations
  77. SGR1900+14
  78. Possible precursor to the SGR1900+14 giant burst
  79. Further Optical Observations of GRB 010324
  80. GRB 010222, Optical Observations
  81. Sub-millimeter Excess/GRB 010222
  82. GRB010222: R-band data
  83. GRB010222, possible increase of optical decay slope
  84. GRB010222: Optical Observations
  85. GRB010222: possible optical counterpart
  86. GRB010222
  87. GRB 010214, Optical Observations
  88. GRB010214, Radio Observations
  89. GRB010214, optical observations
  90. Possible InfraRed Transient of GRB 010214.
  91. GRB010126 optical observations
  92. IPN TRIANGULATION OF GRB010126
  93. GRB 001212 Optical Observation
  94. GRB 001212 possible OA in 2MASS
  95. GRB 001212 possible OA
  96. Confirmation of IPN position for GRB001204
  97. Optical/NIR observations of GRB001109
  98. GRB 001018, Possible Radio Afterglow
  99. HETE positions added to GCN
  100. GRB000926 - Optical observations

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