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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"
  1. Possible GRB20030107 seen by SPI-ACS
  2. Possible GRB 20030105 seen by SPI ACS
  3. IPN triangulation of GRB030102 (annulus)
  4. GRB on 20030102 seen by SPI-ACS
  5. VLT spectroscopy of the probable host of GRB 021211
  6. GRB on 20030101 seen by SPI-ACS
  7. IPN triangulation of GRB030101 (two large error boxes)
  8. GRB021226
  9. GRB 021211: Probable Host and Underlying Supernova
  10. GRB 021226 registration by Helicon/Coronas-F
  11. Probable GRB in INTEGRAL SPI-ACS
  12. IPN triangulation of GRB021223 (two large error boxes)
  13. GRB021211, radio observations
  14. GRB 021112: Evidence for Another Dark Optical Afterglow
  15. GRB 021219: OSN optical observations
  16. GRB021219: Radio Observations
  17. GRB021219, optical observations
  18. IPN triangulation of GRB021219 - CORRECTION
  19. IPN triangulation of GRB021219
  20. GRB021219, optical observation by MASTER
  21. GRB021219: Correction to GCN 1766
  22. GRB021219 refined position with INTEGRAL
  23. VLT spectra of GRB 021211 revisited
  24. GRB021219: a long GRB localized by INTEGRAL
  25. GRB021211: APO optical observations
  26. IPN detection of continued activity from SGR1806-20
  27. IPN triangulation of GRB021215 (large error box)
  28. IPN triangulation of GRB021214 (annulus)
  29. XRF 020903 : HST observations
  30. GRB 021201: Optical Observations
  31. GRB 021211, optical observations
  32. GRB 021211: CTIO observations
  33. GRB021211: Measurement of Early Time Afterglow
  34. VLT spectrum of GRB 021211
  35. IPN triangulation of GRB021211B (two large error boxes)
  36. GRB 021211: early break in light curve
  37. GRB021211, BVRI field photometry
  38. GRB021211: Optical observations in CrAO
  39. GRB 021211, IR observations
  40. GRB 021211, optical observations
  41. GRB 021211: Optical Observations
  42. GRB021211: Kiso Observations
  43. GRB021204: Kiso Observations
  44. GRB 021201, optical observations
  45. GRB 021211: Radio Observations
  46. GRB021211: Optical observations
  47. GRB 021201 (short/hard), NOT observations
  48. SUB-MM SEARCH FOR GRB 021211
  49. Chandra observation of the IPN error box of GRB021201 (short/hard)
  50. GRB 021211 Milagro GeV/TeV Observations
  51. GRB 021211, R- and I-band observations
  52. GRB021211 - Upper limits from recent and historical observations
  53. GRB021211, OT at 108 s
  54. GRB021211 (HETE2493), OT at 143 sec
  55. GRB 021204: I-band Observations
  56. GRB021211 (=H2493): A Bright, Long GRB Localized by HETE-2 in Near-Real Time
  57. HETE 2493: Optical observations
  58. HETE 2493: Optical observations
  59. HETE 2493: Optical candidate
  60. GRB 021204: Optical Observations at RIKEN
  61. GRB 021125: Radio Observations
  62. IPN triangulation of GRB021206 (small error box)
  63. IPN triangulation of GRB021206 (exceptionally bright; annulus only)
  64. IPN detection of renewed activity from SGR1806-20
  65. IPN triangulation of GRB021205 (large error box)
  66. GRB 021104, GRB 021112 and GRB 021113 - Milagro GeV/TeV Observations
  67. GRB021201, BVRcIc field photometry
  68. GRB 021201, Radio Observations
  69. GRB 021201: Optical Observations
  70. GRB 021201: BOOTES simultaneous optical observations
  71. IPN triangulation of GRB021201 (short/hard burst, small error box)
  72. Radio Catalog of GRB Afterglows
  73. GRB021004, late time optical observations
  74. GRB021004 Chandra Observation
  75. IPN detection of continued SGR1900+14 activity
  76. GRB021125 refined position
  77. IPN triangulation of GRB021115 (annulus)
  78. IPN triangulation of GRB021125B (two large error boxes)
  79. IPN triangulation of GRB021119 (large error box)
  80. IPN triangulation of GRB021125B (annulus)
  81. Improved IPN error box for GRB021125
  82. IPN BURST POSITION
  83. IPN triangulation of GRB021125 (INTEGRAL BURST)
  84. GRB021125 : A long GRB localized by INTEGRAL
  85. IPN confirmation of the reactivation of SGR1900+14
  86. IPN detection of possible reactivation of SGR1900+14
  87. GRB021113, SPI ACS observation
  88. IPN triangulation of GRB021119 (annulus)
  89. GRB 021112: Afterglow or Variable Star?
  90. GRB021113: optical observations at Bisei
  91. GRB 021113: Evidence for a Dark Optical Afterglow
  92. GRB 021112, Radio Observations
  93. GRB021112, BVRI field photometry
  94. GRB 021112: Variable Source in R-band search
  95. GRB021112: Optical Observations
  96. GRB021113: Kiso Observations
  97. IPN triangulation of GRB021109 (portion of annulus)
  98. IPN triangulation of GRB021113 (=H2449; annulus)
  99. IPN triangulation of GRB021108 (CORRECTION; TWO LARGE ERROR BOXES)
  100. GRB 021113: Optical observations

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