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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"

41637 results found.

  1. GRB021004: Upper limits from recent and historical observations
  2. XRF020903, BVRI field photometry
  3. GRB021004: optical observations at Nyrola
  4. GRB021004: Absorption redshift
  5. GRB021004(=H2380): Revised Localization with HETE Soft X-ray
  6. GRB021004: optical observations at Bisei
  7. GRB 021004: Kyoto observation
  8. GRB021004: Optical Afterglow
  9. XRF020903: TNG and Asiago photometry
  10. GRB 020903: Optical observations at RIKEN
  11. XRF 020903: Correction to GCN 1560
  12. XRF 020903: VRI observations
  13. IPN triangulation of GRB020926 (single large error box)
  14. GRB 020903: correction to GCN 1557
  15. XRF 020903: R band observations
  16. XRF 020903: Archival Optical Images
  17. Radio Observations of XRF 020903: The Missing Link
  18. XRF 020903: Supernova
  19. IPN triangulation of GRB020926 (two large error boxes)
  20. GRB020924 (ecliptic latitude-only localization)
  21. IPN triangulation of GRB020914B
  22. Improved IPN position for GRB020918 (two large error boxes)
  23. IPN triangulation of GRB020914 - clarification and additional information
  24. IPN triangulation of GRB020914
  25. GRB 020305: HST/STIS observations
  26. IPN GCN Circulars now to be issued without restriction
  27. XRF 020903: optical observation at Kyoto
  28. GRB020322 : HST/STIS observations
  29. XRF 020903: Optical observations
  30. IPN triangulation of GRB020904
  31. XRF 020903: Optical observations
  32. XRF 020903, optical observations
  33. GRB020903(=H2314): An X-Ray Flash Localized by HETE
  34. INTEGRAL GRBs added to GCN
  35. GRB020813: optical observation
  36. GRB020812: optical observation
  37. GRB020819(=H2275): Revised Localization with HETE Soft X-ray
  38. GRB020813: High-resolution optical spectroscopy
  39. GRB020819: optical observations at Bisei
  40. GRB020812: negative optical observations
  41. GRB 020812: optical observation at Kyoto University
  42. Second epoch K band imaging of GRB 020819
  43. GRB020813, Baade 6.5m data now available
  44. GRB 020813 : HST observations
  45. Confirming no variability for GRB02081
  46. GRB020819 : Optical observations at KISO
  47. GRB 020812: early time optical observation at Ouda Station
  48. GRB020813: VRI Decay Slopes
  49. GRB020813: Magellan BVRI Photometry
  50. GRB 020819 : OT candidate - confirmation of non variability
  51. GRB 020819: Optical observations
  52. K band observation of GRB 020819
  53. GRB020819: optical observations
  54. IPN triangulation of GRB020819 (HETE 2275)
  55. HETE 2275: Optical observations
  56. GRB020813: optical and NIR observations
  57. GRB020813: Fading X-ray Afterglow Observed with Chandra
  58. GRB020813, UBVRI field calibration
  59. GRB020813: optical observations at Bisei
  60. GRB020813: V-band decay slope
  61. GRB020812: NIR observations
  62. Polarimetry of GRB020813: evidence for variability
  63. GRB020813 IRAM millimeter observations
  64. GRB020812: optical observations
  65. GRB020813: High-Resolution Optical Observations
  66. GRB020813(=H2262): Revised Localization with HETE SXC
  67. GRB 020812: optical observation at Bisei
  68. GRB020813: Early Time Magnitude
  69. GRB020813: optical observations; possible host galaxy
  70. GRB 020813, radio detection
  71. GRB 020812 : optical afterglow candidate
  72. GRB020813, optical observations
  73. Millimeter observation of GRB 020813
  74. GRB020812: optical observations
  75. GRB 020813 : KISO multiband optical observations
  76. GRB020813, optical observations
  77. IPN error box for GRB020813
  78. IPN triangulation of GRB020813
  79. GRB020812: possible afterglow candidate
  80. GRB020812: possible afterglow candidate
  81. GRB020813, astrometric position
  82. Spectropolarimetry of GRB 020813
  83. GRB 020813 Afterglow Observations; Possible break
  84. GRB 020813: Absorption redshift
  85. GRB 020813 multiband optical observations
  86. GRB020813: optical afterglow
  87. GRB020813: Fading of Candidate OT
  88. GRB020813: Candidate Optical Afterglow
  89. GRB 020812 optical observation
  90. GRB 020715, optical observations
  91. GRB 020714, optical observations
  92. GRB020801: Imaging of Suggested OT Counterpart at the Magellan
  93. GRB020801: Candidate OT present in DSS
  94. HST Imaging of the Host of GRB 011121
  95. GRB020801, optical afterglow candidate
  96. GRB020331: Late-time Optical Light Curve (re-submission)
  97. GRB020331: Late-time Optical Light Curve
  98. GRB 020405: HST observations reveal red bump
  99. GRB 020410: Discovery of Probable OT by HST
  100. GRB 020124, HST observations of the fading afterglow

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