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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"

20602 results found.

  1. GRB 021004 continued IR fading
  2. GRB 021004, spectroscopic observations
  3. GRB021004: not fading anymore?
  4. GRB 021004: Optical Photometry at 2.5 Days
  5. GRB 021004: polarimetric observations
  6. GRB 021004: V-band Polarimetric Observations
  7. GRB021004: Update Bisei photometric data
  8. GRB021004, Optical Observations
  9. GRB 021004: Optical observations at RIKEN
  10. GRB 021004: Optical Observations
  11. GRB 021004: Optical Photometry at 1.5 Days
  12. GRB021004, Optical Observations
  13. GRB 021004: Optical observations
  14. GRB 021004, optical observations
  15. GRB021004: Optical Spectroscopy
  16. GRB 021004: Optical Observations
  17. GRB 021004, SPM optical observations
  18. GRB 021004, optical observations
  19. GRB 021004: radio observations
  20. GRB 021004: steepening of the optical decay slope
  21. GRB021004: Upper limits from recent and historical observations
  22. GRB021004: optical observations at Nyrola
  23. GRB021004: optical observations at Bisei
  24. GRB021004: Optical Afterglow
  25. XRF020903: TNG and Asiago photometry
  26. GRB 020903: Optical observations at RIKEN
  27. XRF 020903: Correction to GCN 1560
  28. XRF 020903: VRI observations
  29. GRB 020903: correction to GCN 1557
  30. XRF 020903: R band observations
  31. XRF 020903: Archival Optical Images
  32. Radio Observations of XRF 020903: The Missing Link
  33. XRF 020903: Supernova
  34. GRB 020305: HST/STIS observations
  35. GRB020322 : HST/STIS observations
  36. XRF 020903: Optical observations
  37. XRF 020903: Optical observations
  38. XRF 020903, optical observations
  39. GRB020813: High-resolution optical spectroscopy
  40. GRB020819: optical observations at Bisei
  41. GRB020812: negative optical observations
  42. GRB 020813 : HST observations
  43. Confirming no variability for GRB02081
  44. GRB020819 : Optical observations at KISO
  45. GRB 020819: Optical observations
  46. K band observation of GRB 020819
  47. GRB020819: optical observations
  48. HETE 2275: Optical observations
  49. GRB020813: optical and NIR observations
  50. GRB020813: Fading X-ray Afterglow Observed with Chandra
  51. GRB020813: optical observations at Bisei
  52. GRB020812: NIR observations
  53. Polarimetry of GRB020813: evidence for variability
  54. GRB020813 IRAM millimeter observations
  55. GRB020812: optical observations
  56. GRB020813: High-Resolution Optical Observations
  57. GRB 020812: optical observation at Bisei
  58. GRB020813: optical observations; possible host galaxy
  59. GRB 020813, radio detection
  60. GRB 020812 : optical afterglow candidate
  61. GRB020813, optical observations
  62. Millimeter observation of GRB 020813
  63. GRB020812: optical observations
  64. GRB 020813 : KISO multiband optical observations
  65. GRB020813, optical observations
  66. GRB 020813 Afterglow Observations; Possible break
  67. GRB 020813 multiband optical observations
  68. GRB 020715, optical observations
  69. GRB 020714, optical observations
  70. GRB020801: Candidate OT present in DSS
  71. HST Imaging of the Host of GRB 011121
  72. GRB020331: Late-time Optical Light Curve (re-submission)
  73. GRB020331: Late-time Optical Light Curve
  74. GRB 020405: HST observations reveal red bump
  75. GRB 020410: Discovery of Probable OT by HST
  76. GRB 020124, HST observations of the fading afterglow
  77. GRB 020705: Optical observations
  78. GRB 020625, optical observations
  79. GRB 020625: Optical observations
  80. GRB 020531: optical photometry of Chandra sources
  81. HETE #2081: Optical observations
  82. The Probable Host Galaxy of GRB/XRF 020427
  83. GRB/XRF 020427, detection of an underlying system with the VLT
  84. Gemini IR Detection of AXP 1E 2259+586 Post-Burst
  85. SGR-like X-ray Bursts from AXP 1E 2259+586: follow-up
  86. AXP 1E2259+586 optical observations
  87. Fading Optical Source in the Field of GRB020531
  88. GRB 020531, INT+WFC deep optical upper limits
  89. SGR-like Bursts from the AXP 1E 2259+586
  90. GRB020405: polarimetric observations
  91. GRB 020531, simultaneous optical observations
  92. GRB 020604, optical observations
  93. GRB 020531/Candidate Redshift
  94. GRB020531: Detection of Candidate Host Galaxy
  95. GRB020531: Second epoch Chandra observations
  96. GRB020604, optical observations
  97. GRB020603, BVRcIc field observations
  98. GRB020531 Optical observations with TAROT
  99. GRB020531 Optical observations with TAROT
  100. GRB 020418, optical/near-IR observations

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