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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"

41630 results found.

  1. GRB021004: Optical Afterglow
  2. XRF020903: TNG and Asiago photometry
  3. GRB 020903: Optical observations at RIKEN
  4. XRF 020903: Correction to GCN 1560
  5. XRF 020903: VRI observations
  6. IPN triangulation of GRB020926 (single large error box)
  7. GRB 020903: correction to GCN 1557
  8. XRF 020903: R band observations
  9. XRF 020903: Archival Optical Images
  10. Radio Observations of XRF 020903: The Missing Link
  11. XRF 020903: Supernova
  12. IPN triangulation of GRB020926 (two large error boxes)
  13. GRB020924 (ecliptic latitude-only localization)
  14. IPN triangulation of GRB020914B
  15. Improved IPN position for GRB020918 (two large error boxes)
  16. IPN triangulation of GRB020914 - clarification and additional information
  17. IPN triangulation of GRB020914
  18. GRB 020305: HST/STIS observations
  19. IPN GCN Circulars now to be issued without restriction
  20. XRF 020903: optical observation at Kyoto
  21. GRB020322 : HST/STIS observations
  22. XRF 020903: Optical observations
  23. IPN triangulation of GRB020904
  24. XRF 020903: Optical observations
  25. XRF 020903, optical observations
  26. GRB020903(=H2314): An X-Ray Flash Localized by HETE
  27. INTEGRAL GRBs added to GCN
  28. GRB020813: optical observation
  29. GRB020812: optical observation
  30. GRB020819(=H2275): Revised Localization with HETE Soft X-ray
  31. GRB020813: High-resolution optical spectroscopy
  32. GRB020819: optical observations at Bisei
  33. GRB020812: negative optical observations
  34. GRB 020812: optical observation at Kyoto University
  35. Second epoch K band imaging of GRB 020819
  36. GRB020813, Baade 6.5m data now available
  37. GRB 020813 : HST observations
  38. Confirming no variability for GRB02081
  39. GRB020819 : Optical observations at KISO
  40. GRB 020812: early time optical observation at Ouda Station
  41. GRB020813: VRI Decay Slopes
  42. GRB020813: Magellan BVRI Photometry
  43. GRB 020819 : OT candidate - confirmation of non variability
  44. GRB 020819: Optical observations
  45. K band observation of GRB 020819
  46. GRB020819: optical observations
  47. IPN triangulation of GRB020819 (HETE 2275)
  48. HETE 2275: Optical observations
  49. GRB020813: optical and NIR observations
  50. GRB020813: Fading X-ray Afterglow Observed with Chandra
  51. GRB020813, UBVRI field calibration
  52. GRB020813: optical observations at Bisei
  53. GRB020813: V-band decay slope
  54. GRB020812: NIR observations
  55. Polarimetry of GRB020813: evidence for variability
  56. GRB020813 IRAM millimeter observations
  57. GRB020812: optical observations
  58. GRB020813: High-Resolution Optical Observations
  59. GRB020813(=H2262): Revised Localization with HETE SXC
  60. GRB 020812: optical observation at Bisei
  61. GRB020813: Early Time Magnitude
  62. GRB020813: optical observations; possible host galaxy
  63. GRB 020813, radio detection
  64. GRB 020812 : optical afterglow candidate
  65. GRB020813, optical observations
  66. Millimeter observation of GRB 020813
  67. GRB020812: optical observations
  68. GRB 020813 : KISO multiband optical observations
  69. GRB020813, optical observations
  70. IPN error box for GRB020813
  71. IPN triangulation of GRB020813
  72. GRB020812: possible afterglow candidate
  73. GRB020812: possible afterglow candidate
  74. GRB020813, astrometric position
  75. Spectropolarimetry of GRB 020813
  76. GRB 020813 Afterglow Observations; Possible break
  77. GRB 020813: Absorption redshift
  78. GRB 020813 multiband optical observations
  79. GRB020813: optical afterglow
  80. GRB020813: Fading of Candidate OT
  81. GRB020813: Candidate Optical Afterglow
  82. GRB 020812 optical observation
  83. GRB 020715, optical observations
  84. GRB 020714, optical observations
  85. GRB020801: Imaging of Suggested OT Counterpart at the Magellan
  86. GRB020801: Candidate OT present in DSS
  87. HST Imaging of the Host of GRB 011121
  88. GRB020801, optical afterglow candidate
  89. GRB020331: Late-time Optical Light Curve (re-submission)
  90. GRB020331: Late-time Optical Light Curve
  91. GRB 020405: HST observations reveal red bump
  92. GRB 020410: Discovery of Probable OT by HST
  93. GRB 020124, HST observations of the fading afterglow
  94. IPN triangulation of GRB020708
  95. GRB 020705: Optical observations
  96. GRB 020625, optical observations
  97. GRB 020625: Optical observations
  98. GRB 020531: optical photometry of Chandra sources
  99. GRB020625 (=H2081): A Long Burst Localized by HETE
  100. HETE #2081: Optical observations

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