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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"

21793 results found.

  1. GRB 021004: Optical Observations
  2. GRB 021004: Optical Photometry at 1.5 Days
  3. GRB021004, Optical Observations
  4. GRB 021004: Optical observations
  5. GRB 021004, optical observations
  6. GRB021004: Optical Spectroscopy
  7. GRB 021004: Optical Observations
  8. GRB 021004, SPM optical observations
  9. GRB 021004, optical observations
  10. GRB 021004: radio observations
  11. GRB 021004: steepening of the optical decay slope
  12. GRB021004: Upper limits from recent and historical observations
  13. GRB021004: optical observations at Nyrola
  14. GRB021004: optical observations at Bisei
  15. GRB021004: Optical Afterglow
  16. XRF020903: TNG and Asiago photometry
  17. GRB 020903: Optical observations at RIKEN
  18. XRF 020903: Correction to GCN 1560
  19. XRF 020903: VRI observations
  20. GRB 020903: correction to GCN 1557
  21. XRF 020903: R band observations
  22. XRF 020903: Archival Optical Images
  23. Radio Observations of XRF 020903: The Missing Link
  24. XRF 020903: Supernova
  25. GRB 020305: HST/STIS observations
  26. GRB020322 : HST/STIS observations
  27. XRF 020903: Optical observations
  28. XRF 020903: Optical observations
  29. XRF 020903, optical observations
  30. GRB020813: High-resolution optical spectroscopy
  31. GRB020819: optical observations at Bisei
  32. GRB020812: negative optical observations
  33. GRB 020813 : HST observations
  34. Confirming no variability for GRB02081
  35. GRB020819 : Optical observations at KISO
  36. GRB 020819: Optical observations
  37. K band observation of GRB 020819
  38. GRB020819: optical observations
  39. HETE 2275: Optical observations
  40. GRB020813: optical and NIR observations
  41. GRB020813: Fading X-ray Afterglow Observed with Chandra
  42. GRB020813: optical observations at Bisei
  43. GRB020812: NIR observations
  44. Polarimetry of GRB020813: evidence for variability
  45. GRB020813 IRAM millimeter observations
  46. GRB020812: optical observations
  47. GRB020813: High-Resolution Optical Observations
  48. GRB 020812: optical observation at Bisei
  49. GRB020813: optical observations; possible host galaxy
  50. GRB 020813, radio detection
  51. GRB 020812 : optical afterglow candidate
  52. GRB020813, optical observations
  53. Millimeter observation of GRB 020813
  54. GRB020812: optical observations
  55. GRB 020813 : KISO multiband optical observations
  56. GRB020813, optical observations
  57. GRB 020813 Afterglow Observations; Possible break
  58. GRB 020813 multiband optical observations
  59. GRB 020715, optical observations
  60. GRB 020714, optical observations
  61. GRB020801: Candidate OT present in DSS
  62. HST Imaging of the Host of GRB 011121
  63. GRB020331: Late-time Optical Light Curve (re-submission)
  64. GRB020331: Late-time Optical Light Curve
  65. GRB 020405: HST observations reveal red bump
  66. GRB 020410: Discovery of Probable OT by HST
  67. GRB 020124, HST observations of the fading afterglow
  68. GRB 020705: Optical observations
  69. GRB 020625, optical observations
  70. GRB 020625: Optical observations
  71. GRB 020531: optical photometry of Chandra sources
  72. HETE #2081: Optical observations
  73. The Probable Host Galaxy of GRB/XRF 020427
  74. GRB/XRF 020427, detection of an underlying system with the VLT
  75. Gemini IR Detection of AXP 1E 2259+586 Post-Burst
  76. SGR-like X-ray Bursts from AXP 1E 2259+586: follow-up
  77. AXP 1E2259+586 optical observations
  78. Fading Optical Source in the Field of GRB020531
  79. GRB 020531, INT+WFC deep optical upper limits
  80. SGR-like Bursts from the AXP 1E 2259+586
  81. GRB020405: polarimetric observations
  82. GRB 020531, simultaneous optical observations
  83. GRB 020604, optical observations
  84. GRB 020531/Candidate Redshift
  85. GRB020531: Detection of Candidate Host Galaxy
  86. GRB020531: Second epoch Chandra observations
  87. GRB020604, optical observations
  88. GRB020603, BVRcIc field observations
  89. GRB020531 Optical observations with TAROT
  90. GRB020531 Optical observations with TAROT
  91. GRB 020418, optical/near-IR observations
  92. GRB 020531, Radio Observations
  93. GRB020531 Optical Observations
  94. GRB020531: Observations with the Chandra X-ray Observatory
  95. GRB 020603: Optical Observations
  96. GRB020531: Upper Limit for Detection of Two TAROT Sources
  97. GRB 020603: Optical observations
  98. GRB 020531 optical observations with TAROT
  99. GRB020531, optical observations
  100. GRB020531: optical observations

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