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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"

43595 results found.

  1. Possible GRB 20030105 seen by SPI ACS
  2. IPN triangulation of GRB030102 (annulus)
  3. GRB on 20030102 seen by SPI-ACS
  4. VLT spectroscopy of the probable host of GRB 021211
  5. GRB on 20030101 seen by SPI-ACS
  6. IPN triangulation of GRB030101 (two large error boxes)
  7. GRB021226
  8. GRB 021211: Probable Host and Underlying Supernova
  9. GRB 021226 registration by Helicon/Coronas-F
  10. Probable GRB in INTEGRAL SPI-ACS
  11. IPN triangulation of GRB021223 (two large error boxes)
  12. GRB021211, radio observations
  13. GRB 021112: Evidence for Another Dark Optical Afterglow
  14. GRB 021219: OSN optical observations
  15. GRB021219: Radio Observations
  16. GRB021219, optical observations
  17. IPN triangulation of GRB021219 - CORRECTION
  18. IPN triangulation of GRB021219
  19. GRB021219, optical observation by MASTER
  20. GRB021219: Correction to GCN 1766
  21. GRB021219 refined position with INTEGRAL
  22. VLT spectra of GRB 021211 revisited
  23. GRB021219: a long GRB localized by INTEGRAL
  24. GRB021211: APO optical observations
  25. IPN detection of continued activity from SGR1806-20
  26. IPN triangulation of GRB021215 (large error box)
  27. IPN triangulation of GRB021214 (annulus)
  28. XRF 020903 : HST observations
  29. GRB 021201: Optical Observations
  30. GRB 021211, optical observations
  31. GRB 021211: CTIO observations
  32. GRB021211: Measurement of Early Time Afterglow
  33. VLT spectrum of GRB 021211
  34. IPN triangulation of GRB021211B (two large error boxes)
  35. GRB 021211: early break in light curve
  36. GRB021211, BVRI field photometry
  37. GRB 021211, IR observations
  38. GRB 021211, optical observations
  39. GRB021211: Kiso Observations
  40. GRB 021201, optical observations
  41. GRB 021211: Radio Observations
  42. GRB021211: Optical observations
  43. GRB 021201 (short/hard), NOT observations
  44. SUB-MM SEARCH FOR GRB 021211
  45. Chandra observation of the IPN error box of GRB021201 (short/hard)
  46. GRB 021211 Milagro GeV/TeV Observations
  47. GRB 021211, R- and I-band observations
  48. GRB021211 - Upper limits from recent and historical observations
  49. GRB021211, OT at 108 s
  50. GRB021211 (HETE2493), OT at 143 sec
  51. GRB 021204: I-band Observations
  52. GRB021211 (=H2493): A Bright, Long GRB Localized by HETE-2 in Near-Real Time
  53. HETE 2493: Optical observations
  54. HETE 2493: Optical candidate
  55. GRB 021204: Optical Observations at RIKEN
  56. GRB 021125: Radio Observations
  57. IPN triangulation of GRB021206 (small error box)
  58. IPN triangulation of GRB021206 (exceptionally bright; annulus only)
  59. IPN detection of renewed activity from SGR1806-20
  60. IPN triangulation of GRB021205 (large error box)
  61. GRB 021104, GRB 021112 and GRB 021113 - Milagro GeV/TeV Observations
  62. GRB021201, BVRcIc field photometry
  63. GRB 021201, Radio Observations
  64. GRB 021201: BOOTES simultaneous optical observations
  65. IPN triangulation of GRB021201 (short/hard burst, small error box)
  66. Radio Catalog of GRB Afterglows
  67. GRB021004, late time optical observations
  68. GRB021004 Chandra Observation
  69. IPN detection of continued SGR1900+14 activity
  70. GRB021125 refined position
  71. IPN triangulation of GRB021115 (annulus)
  72. IPN triangulation of GRB021125B (two large error boxes)
  73. IPN triangulation of GRB021119 (large error box)
  74. IPN triangulation of GRB021125B (annulus)
  75. Improved IPN error box for GRB021125
  76. IPN BURST POSITION
  77. IPN triangulation of GRB021125 (INTEGRAL BURST)
  78. GRB021125 : A long GRB localized by INTEGRAL
  79. IPN confirmation of the reactivation of SGR1900+14
  80. IPN detection of possible reactivation of SGR1900+14
  81. GRB021113, SPI ACS observation
  82. IPN triangulation of GRB021119 (annulus)
  83. GRB 021112: Afterglow or Variable Star?
  84. GRB021113: optical observations at Bisei
  85. GRB 021113: Evidence for a Dark Optical Afterglow
  86. GRB 021112, Radio Observations
  87. GRB021112, BVRI field photometry
  88. GRB 021112: Variable Source in R-band search
  89. GRB021112: Optical Observations
  90. GRB021113: Kiso Observations
  91. IPN triangulation of GRB021109 (portion of annulus)
  92. IPN triangulation of GRB021113 (=H2449; annulus)
  93. IPN triangulation of GRB021108 (CORRECTION; TWO LARGE ERROR BOXES)
  94. GRB 021113: Optical observations
  95. GRB 021112: RAPTOR Observations
  96. GRB 021113: Optical Observations
  97. GRB021113 (=H2449): A Long GRB Localized by HETE
  98. GRB 021112: R-band search
  99. IPN triangulation of GRB021108 (large error box)
  100. GRB021112 (=H2448): A Long GRB Localized by HETE

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