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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"

42578 results found.

  1. IPN triangulation of GRB030115B (annulus)
  2. ANNOUNCEMENT ON INTEGRAL GRB ALERTS
  3. Distribution of INTEGRAL SPI-ACS triggers
  4. GRB030115: R-band observations at Asiago
  5. GRB030115: TAROT optical observations
  6. GRB 021211: VLT spectrum
  7. GRB 030115, no optical candidate
  8. GRB 030115, optical observations
  9. GRB 030115, optical candidate
  10. Possible GRB030113 seen by SPI ACS
  11. Probable GRB030112B seen by SPI ACS
  12. Probable GRB030112 seen by SPI ACS
  13. Information about where HETE will be pointing
  14. Possible GRB030111 seen by SPI ACS
  15. Possible GRB030110b seen by SPI ACS
  16. Possible GRB 030110 seen by SPI ACS
  17. IPN triangulation of GRB030109 (annulus)
  18. IPN triangulation of GRB030105 (large error box)
  19. IPN triangulation of GRB030102B (refined localization - portion of annulus)
  20. Possible GRB 20030109 seen by SPI ACS
  21. IPN triangulation of GRB030102B (portion of annulus)
  22. IPN triangulation of GRB030102A (large error box)
  23. Coronas-F -Wind triangulation of GRB030102
  24. Possible GRB20030107 seen by SPI-ACS
  25. Possible GRB 20030105 seen by SPI ACS
  26. IPN triangulation of GRB030102 (annulus)
  27. GRB on 20030102 seen by SPI-ACS
  28. VLT spectroscopy of the probable host of GRB 021211
  29. GRB on 20030101 seen by SPI-ACS
  30. IPN triangulation of GRB030101 (two large error boxes)
  31. GRB021226
  32. GRB 021211: Probable Host and Underlying Supernova
  33. GRB 021226 registration by Helicon/Coronas-F
  34. Probable GRB in INTEGRAL SPI-ACS
  35. IPN triangulation of GRB021223 (two large error boxes)
  36. GRB021211, radio observations
  37. GRB 021112: Evidence for Another Dark Optical Afterglow
  38. GRB 021219: OSN optical observations
  39. GRB021219: Radio Observations
  40. GRB021219, optical observations
  41. IPN triangulation of GRB021219 - CORRECTION
  42. IPN triangulation of GRB021219
  43. GRB021219, optical observation by MASTER
  44. GRB021219: Correction to GCN 1766
  45. GRB021219 refined position with INTEGRAL
  46. VLT spectra of GRB 021211 revisited
  47. GRB021219: a long GRB localized by INTEGRAL
  48. GRB021211: APO optical observations
  49. IPN detection of continued activity from SGR1806-20
  50. IPN triangulation of GRB021215 (large error box)
  51. IPN triangulation of GRB021214 (annulus)
  52. XRF 020903 : HST observations
  53. GRB 021201: Optical Observations
  54. GRB 021211, optical observations
  55. GRB 021211: CTIO observations
  56. GRB021211: Measurement of Early Time Afterglow
  57. VLT spectrum of GRB 021211
  58. IPN triangulation of GRB021211B (two large error boxes)
  59. GRB 021211: early break in light curve
  60. GRB021211, BVRI field photometry
  61. GRB 021211, IR observations
  62. GRB 021211, optical observations
  63. GRB 021211: Optical Observations
  64. GRB021211: Kiso Observations
  65. GRB 021201, optical observations
  66. GRB 021211: Radio Observations
  67. GRB 021201 (short/hard), NOT observations
  68. SUB-MM SEARCH FOR GRB 021211
  69. Chandra observation of the IPN error box of GRB021201 (short/hard)
  70. GRB 021211 Milagro GeV/TeV Observations
  71. GRB 021211, R- and I-band observations
  72. GRB021211 - Upper limits from recent and historical observations
  73. GRB021211, OT at 108 s
  74. GRB021211 (HETE2493), OT at 143 sec
  75. GRB 021204: I-band Observations
  76. GRB021211 (=H2493): A Bright, Long GRB Localized by HETE-2 in Near-Real Time
  77. HETE 2493: Optical observations
  78. HETE 2493: Optical candidate
  79. GRB 021204: Optical Observations at RIKEN
  80. GRB 021125: Radio Observations
  81. IPN triangulation of GRB021206 (small error box)
  82. IPN triangulation of GRB021206 (exceptionally bright; annulus only)
  83. IPN detection of renewed activity from SGR1806-20
  84. IPN triangulation of GRB021205 (large error box)
  85. GRB 021104, GRB 021112 and GRB 021113 - Milagro GeV/TeV Observations
  86. GRB021201, BVRcIc field photometry
  87. GRB 021201, Radio Observations
  88. GRB 021201: BOOTES simultaneous optical observations
  89. IPN triangulation of GRB021201 (short/hard burst, small error box)
  90. Radio Catalog of GRB Afterglows
  91. GRB021004, late time optical observations
  92. GRB021004 Chandra Observation
  93. IPN detection of continued SGR1900+14 activity
  94. GRB021125 refined position
  95. IPN triangulation of GRB021115 (annulus)
  96. IPN triangulation of GRB021125B (two large error boxes)
  97. IPN triangulation of GRB021119 (large error box)
  98. IPN triangulation of GRB021125B (annulus)
  99. Improved IPN error box for GRB021125
  100. IPN BURST POSITION

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