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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"

35441 results found.

  1. GRB 030115: APO Optical Observations
  2. GRB 030115, no optical candidate
  3. GRB 030115, optical observations
  4. GRB 030115, optical candidate
  5. Possible GRB030113 seen by SPI ACS
  6. Probable GRB030112B seen by SPI ACS
  7. Probable GRB030112 seen by SPI ACS
  8. Possible GRB030111 seen by SPI ACS
  9. Possible GRB030110b seen by SPI ACS
  10. Possible GRB 030110 seen by SPI ACS
  11. IPN triangulation of GRB030109 (annulus)
  12. IPN triangulation of GRB030105 (large error box)
  13. IPN triangulation of GRB030102B (refined localization - portion of annulus)
  14. Possible GRB 20030109 seen by SPI ACS
  15. IPN triangulation of GRB030102B (portion of annulus)
  16. IPN triangulation of GRB030102A (large error box)
  17. Possible GRB20030107 seen by SPI-ACS
  18. Possible GRB 20030105 seen by SPI ACS
  19. IPN triangulation of GRB030102 (annulus)
  20. GRB on 20030102 seen by SPI-ACS
  21. VLT spectroscopy of the probable host of GRB 021211
  22. GRB on 20030101 seen by SPI-ACS
  23. IPN triangulation of GRB030101 (two large error boxes)
  24. GRB021226
  25. GRB 021211: Probable Host and Underlying Supernova
  26. GRB 021226 registration by Helicon/Coronas-F
  27. Probable GRB in INTEGRAL SPI-ACS
  28. IPN triangulation of GRB021223 (two large error boxes)
  29. GRB021211, radio observations
  30. GRB 021112: Evidence for Another Dark Optical Afterglow
  31. GRB 021219: OSN optical observations
  32. GRB021219: Radio Observations
  33. IPN triangulation of GRB021219 - CORRECTION
  34. IPN triangulation of GRB021219
  35. GRB021219, optical observation by MASTER
  36. GRB021219: Correction to GCN 1766
  37. VLT spectra of GRB 021211 revisited
  38. GRB021219: a long GRB localized by INTEGRAL
  39. IPN detection of continued activity from SGR1806-20
  40. IPN triangulation of GRB021215 (large error box)
  41. IPN triangulation of GRB021214 (annulus)
  42. XRF 020903 : HST observations
  43. GRB 021201: Optical Observations
  44. GRB 021211, optical observations
  45. GRB 021211: CTIO observations
  46. GRB021211: Measurement of Early Time Afterglow
  47. VLT spectrum of GRB 021211
  48. IPN triangulation of GRB021211B (two large error boxes)
  49. GRB 021211: early break in light curve
  50. GRB021211, BVRI field photometry
  51. GRB 021211, IR observations
  52. GRB 021211, optical observations
  53. GRB 021211: Optical Observations
  54. GRB021211: Kiso Observations
  55. GRB021204: Kiso Observations
  56. GRB 021201, optical observations
  57. GRB 021211: Radio Observations
  58. GRB 021201 (short/hard), NOT observations
  59. SUB-MM SEARCH FOR GRB 021211
  60. GRB 021211 Milagro GeV/TeV Observations
  61. GRB 021211, R- and I-band observations
  62. GRB021211 - Upper limits from recent and historical observations
  63. GRB 021204: I-band Observations
  64. GRB021211 (=H2493): A Bright, Long GRB Localized by HETE-2 in Near-Real Time
  65. HETE 2493: Optical observations
  66. GRB 021204: Optical Observations at RIKEN
  67. GRB 021125: Radio Observations
  68. IPN triangulation of GRB021206 (small error box)
  69. IPN triangulation of GRB021206 (exceptionally bright; annulus only)
  70. IPN detection of renewed activity from SGR1806-20
  71. IPN triangulation of GRB021205 (large error box)
  72. GRB 021104, GRB 021112 and GRB 021113 - Milagro GeV/TeV Observations
  73. GRB021201, BVRcIc field photometry
  74. GRB 021201, Radio Observations
  75. GRB 021201: Optical Observations
  76. GRB 021201: BOOTES simultaneous optical observations
  77. IPN triangulation of GRB021201 (short/hard burst, small error box)
  78. Radio Catalog of GRB Afterglows
  79. GRB021004, late time optical observations
  80. GRB021004 Chandra Observation
  81. IPN detection of continued SGR1900+14 activity
  82. IPN triangulation of GRB021115 (annulus)
  83. IPN triangulation of GRB021125B (two large error boxes)
  84. IPN triangulation of GRB021119 (large error box)
  85. IPN triangulation of GRB021125B (annulus)
  86. Improved IPN error box for GRB021125
  87. IPN triangulation of GRB021125 (INTEGRAL BURST)
  88. GRB021125 : A long GRB localized by INTEGRAL
  89. IPN confirmation of the reactivation of SGR1900+14
  90. IPN detection of possible reactivation of SGR1900+14
  91. GRB021113, SPI ACS observation
  92. IPN triangulation of GRB021119 (annulus)
  93. GRB 021112: Afterglow or Variable Star?
  94. GRB021113: optical observations at Bisei
  95. GRB 021113: Evidence for a Dark Optical Afterglow
  96. GRB 021112, Radio Observations
  97. GRB021112, BVRI field photometry
  98. GRB 021112: Variable Source in R-band search
  99. GRB021112: Optical Observations
  100. GRB021113: Kiso Observations

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