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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"

37500 results found.

  1. IPN triangulation of GRB030220 (annulus)
  2. GRB: Non-Referencing of GCN Circulars.
  3. IPN triangulation of GRB030218 (annulus)
  4. IPN triangulation of GRB030217 (small error box)
  5. IPN triangulation of GRB030215C (annulus)
  6. IPN triangulation of GRB030217 (annulus)
  7. IPN triangulation of GRB030216 (annulus)
  8. IPN triangulation of GRB030215A and GRB030215B (annuli)
  9. GRB030115, WSRT radio observations - correction to GCN 1864
  10. GRB 030131: marginal optical detection
  11. GRB030115, WSRT radio observations
  12. IPN triangulation of GRB030206 (annulus)
  13. IPN triangulation of GRB030208 (annulus)
  14. GRB 030204: Optical Observations
  15. GRB030204 field photometry
  16. GRB020819: Kiso R and I band observations
  17. GRB 030204: Correction to GCN 1856
  18. GRB 030115: Optical Observations
  19. GRB 030204, optical observations
  20. IPN triangulation of GRB030204 (small error box)
  21. IPN triangulation of GRB030202 (annulus)
  22. GRB 030131, optical observations
  23. GRB030131: Kiso optical limit for corrected position
  24. GRB030131: Optical limits for corrected position
  25. GRB 030131: afterglow candidate
  26. GRB 030115, late-time optical observations
  27. GRB030131: corrected INTEGRAL position
  28. Type Ic SN2003L (SN/GRB?), optical spectrum
  29. GRB030131: Kiso Observations
  30. GRB 020819: Host galaxy at Radio Position
  31. IPN triangulation of GRB030131 - CORRECTION
  32. GRB 020819: afterglow candidate
  33. IPN triangulation of GRB030131
  34. GRB 030131 optical observations
  35. GRB 030131 optical observations
  36. A long GRB detected by INTEGRAL
  37. GRB030115: 1.2 mm upper limits with MAMBO @ IRAM 30m
  38. Type Ic SN2003L (SN/GRB?) Radio Observations
  39. IPN triangulation of GRB030127 (annulus)
  40. GRB030115 submm upper limit
  41. IPN triangulation of GRB030119 (two large error boxes)
  42. GRB 030115: Further IR observations with IRSF/SIRIUS
  43. IPN triangulation of GRB030117 (two large error boxes)
  44. Publicizing GRB Discoveries - A Message from NASA HQ
  45. GRB 030115: Radio detection of IR candidate
  46. GRB 030115, simultaneous observations by BOOTES-1
  47. GRB 030115: IR observations with IRSF/SIRIUS
  48. IPN triangulation of GRB030115C (large error box)
  49. GRB030115: R-band counterpart of IR candidate
  50. GRB030115, afterglow candidate
  51. GRB 021211: R-band observations at late-time
  52. GRB030115: Optical Observations, Swiss Telescope at La Silla (ESO, Chile)
  53. IPN triangulation of GRB030115B (small error box)
  54. GRB 030115 : Possible IR counterpart
  55. GRB 030115: Radio Observations
  56. GRB030115 (=H2533): A Long GRB Localized by the HETE WXM and SXC
  57. Distribution of INTEGRAL SPI-ACS triggers for GRB bursts
  58. IPN triangulation of GRB030115B (annulus)
  59. ANNOUNCEMENT ON INTEGRAL GRB ALERTS
  60. Distribution of INTEGRAL SPI-ACS triggers
  61. GRB030115: R-band observations at Asiago
  62. GRB030115: TAROT optical observations
  63. GRB 021211: VLT spectrum
  64. GRB 030115: APO Optical Observations
  65. GRB 030115, no optical candidate
  66. GRB 030115, optical observations
  67. GRB 030115, optical candidate
  68. Possible GRB030113 seen by SPI ACS
  69. Probable GRB030112B seen by SPI ACS
  70. Probable GRB030112 seen by SPI ACS
  71. Possible GRB030111 seen by SPI ACS
  72. Possible GRB030110b seen by SPI ACS
  73. Possible GRB 030110 seen by SPI ACS
  74. IPN triangulation of GRB030109 (annulus)
  75. IPN triangulation of GRB030105 (large error box)
  76. IPN triangulation of GRB030102B (refined localization - portion of annulus)
  77. Possible GRB 20030109 seen by SPI ACS
  78. IPN triangulation of GRB030102B (portion of annulus)
  79. IPN triangulation of GRB030102A (large error box)
  80. Possible GRB20030107 seen by SPI-ACS
  81. Possible GRB 20030105 seen by SPI ACS
  82. IPN triangulation of GRB030102 (annulus)
  83. GRB on 20030102 seen by SPI-ACS
  84. VLT spectroscopy of the probable host of GRB 021211
  85. GRB on 20030101 seen by SPI-ACS
  86. IPN triangulation of GRB030101 (two large error boxes)
  87. GRB021226
  88. GRB 021211: Probable Host and Underlying Supernova
  89. GRB 021226 registration by Helicon/Coronas-F
  90. Probable GRB in INTEGRAL SPI-ACS
  91. IPN triangulation of GRB021223 (two large error boxes)
  92. GRB021211, radio observations
  93. GRB 021112: Evidence for Another Dark Optical Afterglow
  94. GRB 021219: OSN optical observations
  95. GRB021219: Radio Observations
  96. IPN triangulation of GRB021219 - CORRECTION
  97. IPN triangulation of GRB021219
  98. GRB021219, optical observation by MASTER
  99. GRB021219: Correction to GCN 1766
  100. VLT spectra of GRB 021211 revisited

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