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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"

32813 results found.

  1. GRB030226 (=U10893): A Long GRB Localized by the HETE WXM and SXC
  2. GRB 030226 simultaneous optical observations
  3. Two absorption systems in GRB 030226
  4. GRB 030226, optical observations
  5. GRB 030226 Optical Spectra and R,I,z' Imaging
  6. GRB 030226, optical observations
  7. GRB 030226: Optical afterglow
  8. GRB 030217: Optical Observations at 4, 5, and 6 Days
  9. IPN triangulation of GRB030223 (annulus)
  10. IPN triangulation of GRB030220 (annulus)
  11. GRB: Non-Referencing of GCN Circulars.
  12. IPN triangulation of GRB030218 (annulus)
  13. IPN triangulation of GRB030217 (small error box)
  14. IPN triangulation of GRB030215C (annulus)
  15. IPN triangulation of GRB030217 (annulus)
  16. IPN triangulation of GRB030216 (annulus)
  17. IPN triangulation of GRB030215A and GRB030215B (annuli)
  18. GRB030115, WSRT radio observations - correction to GCN 1864
  19. GRB 030131: marginal optical detection
  20. GRB030115, WSRT radio observations
  21. IPN triangulation of GRB030206 (annulus)
  22. IPN triangulation of GRB030208 (annulus)
  23. GRB 030204: Optical Observations
  24. GRB030204 field photometry
  25. GRB020819: Kiso R and I band observations
  26. GRB 030204: Correction to GCN 1856
  27. GRB 030115: Optical Observations
  28. GRB 030204, optical observations
  29. IPN triangulation of GRB030204 (small error box)
  30. IPN triangulation of GRB030202 (annulus)
  31. GRB 030131, optical observations
  32. GRB030131: Kiso optical limit for corrected position
  33. GRB030131: Optical limits for corrected position
  34. GRB 030131: afterglow candidate
  35. GRB 030115, late-time optical observations
  36. GRB030131: corrected INTEGRAL position
  37. Type Ic SN2003L (SN/GRB?), optical spectrum
  38. GRB030131: Kiso Observations
  39. GRB 020819: Host galaxy at Radio Position
  40. IPN triangulation of GRB030131 - CORRECTION
  41. GRB 020819: afterglow candidate
  42. IPN triangulation of GRB030131
  43. GRB 030131 optical observations
  44. GRB 030131 optical observations
  45. A long GRB detected by INTEGRAL
  46. GRB030115: 1.2 mm upper limits with MAMBO @ IRAM 30m
  47. Type Ic SN2003L (SN/GRB?) Radio Observations
  48. IPN triangulation of GRB030127 (annulus)
  49. GRB030115 submm upper limit
  50. IPN triangulation of GRB030119 (two large error boxes)
  51. GRB 030115: Further IR observations with IRSF/SIRIUS
  52. IPN triangulation of GRB030117 (two large error boxes)
  53. Publicizing GRB Discoveries - A Message from NASA HQ
  54. GRB 030115: Radio detection of IR candidate
  55. GRB 030115, simultaneous observations by BOOTES-1
  56. GRB 030115: IR observations with IRSF/SIRIUS
  57. IPN triangulation of GRB030115C (large error box)
  58. GRB030115: R-band counterpart of IR candidate
  59. GRB030115, afterglow candidate
  60. GRB 021211: R-band observations at late-time
  61. GRB030115: Optical Observations, Swiss Telescope at La Silla (ESO, Chile)
  62. IPN triangulation of GRB030115B (small error box)
  63. GRB 030115 : Possible IR counterpart
  64. GRB 030115: Radio Observations
  65. GRB030115 (=H2533): A Long GRB Localized by the HETE WXM and SXC
  66. Distribution of INTEGRAL SPI-ACS triggers for GRB bursts
  67. IPN triangulation of GRB030115B (annulus)
  68. ANNOUNCEMENT ON INTEGRAL GRB ALERTS
  69. Distribution of INTEGRAL SPI-ACS triggers
  70. GRB030115: R-band observations at Asiago
  71. GRB030115: TAROT optical observations
  72. GRB 021211: VLT spectrum
  73. GRB 030115: APO Optical Observations
  74. GRB 030115, no optical candidate
  75. GRB 030115, optical observations
  76. GRB 030115, optical candidate
  77. Possible GRB030113 seen by SPI ACS
  78. Probable GRB030112B seen by SPI ACS
  79. Probable GRB030112 seen by SPI ACS
  80. Possible GRB030111 seen by SPI ACS
  81. Possible GRB030110b seen by SPI ACS
  82. Possible GRB 030110 seen by SPI ACS
  83. IPN triangulation of GRB030109 (annulus)
  84. IPN triangulation of GRB030105 (large error box)
  85. IPN triangulation of GRB030102B (refined localization - portion of annulus)
  86. Possible GRB 20030109 seen by SPI ACS
  87. IPN triangulation of GRB030102B (portion of annulus)
  88. IPN triangulation of GRB030102A (large error box)
  89. Possible GRB20030107 seen by SPI-ACS
  90. Possible GRB 20030105 seen by SPI ACS
  91. IPN triangulation of GRB030102 (annulus)
  92. GRB on 20030102 seen by SPI-ACS
  93. VLT spectroscopy of the probable host of GRB 021211
  94. GRB on 20030101 seen by SPI-ACS
  95. IPN triangulation of GRB030101 (two large error boxes)
  96. GRB021226
  97. GRB 021211: Probable Host and Underlying Supernova
  98. GRB 021226 registration by Helicon/Coronas-F
  99. Probable GRB in INTEGRAL SPI-ACS
  100. IPN triangulation of GRB021223 (two large error boxes)

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