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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').
  1. Possible GRB030113 seen by SPI ACS
  2. Probable GRB030112B seen by SPI ACS
  3. Probable GRB030112 seen by SPI ACS
  4. Information about where HETE will be pointing
  5. Possible GRB030111 seen by SPI ACS
  6. Possible GRB030110b seen by SPI ACS
  7. Possible GRB 030110 seen by SPI ACS
  8. IPN triangulation of GRB030109 (annulus)
  9. IPN triangulation of GRB030105 (large error box)
  10. IPN triangulation of GRB030102B (refined localization - portion of annulus)
  11. Possible GRB 20030109 seen by SPI ACS
  12. IPN triangulation of GRB030102A - correction to peak flux
  13. IPN triangulation of GRB030102B (portion of annulus)
  14. IPN triangulation of GRB030102A (large error box)
  15. Coronas-F -Wind triangulation of GRB030102
  16. Possible GRB20030107 seen by SPI-ACS
  17. Possible GRB 20030105 seen by SPI ACS
  18. IPN triangulation of GRB030102 (annulus)
  19. GRB on 20030102 seen by SPI-ACS
  20. VLT spectroscopy of the probable host of GRB 021211
  21. GRB on 20030101 seen by SPI-ACS
  22. IPN triangulation of GRB030101 (two large error boxes)
  23. GRB021226
  24. GRB 021211: Probable Host and Underlying Supernova
  25. GRB 021226 registration by Helicon/Coronas-F
  26. Probable GRB in INTEGRAL SPI-ACS
  27. IPN triangulation of GRB021223 (two large error boxes)
  28. GRB021211, radio observations
  29. GRB 021112: Evidence for Another Dark Optical Afterglow
  30. GRB 021219: OSN optical observations
  31. GRB021219: Radio Observations
  32. GRB021219, optical 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. GRB021219 refined position with INTEGRAL
  38. VLT spectra of GRB 021211 revisited
  39. GRB021219: a long GRB localized by INTEGRAL
  40. GRB021211: APO optical observations
  41. IPN detection of continued activity from SGR1806-20
  42. IPN triangulation of GRB021215 (large error box)
  43. IPN triangulation of GRB021214 (annulus)
  44. XRF 020903 : HST observations
  45. GRB 021201: Optical Observations
  46. GRB 021211, optical observations
  47. GRB 021211: CTIO observations
  48. GRB021211: Measurement of Early Time Afterglow
  49. VLT spectrum of GRB 021211
  50. IPN triangulation of GRB021211B (two large error boxes)
  51. GRB 021211: early break in light curve
  52. GRB021211, BVRI field photometry
  53. GRB021211: Optical observations in CrAO
  54. GRB 021211, IR observations
  55. GRB 021211, optical observations
  56. GRB 021211: Optical Observations
  57. GRB021211: Kiso Observations
  58. GRB021204: Kiso Observations
  59. GRB 021201, optical observations
  60. GRB 021211: Radio Observations
  61. GRB021211: Optical observations
  62. GRB 021201 (short/hard), NOT observations
  63. SUB-MM SEARCH FOR GRB 021211
  64. Chandra observation of the IPN error box of GRB021201 (short/hard)
  65. GRB 021211 Milagro GeV/TeV Observations
  66. GRB 021211, R- and I-band observations
  67. GRB021211 - Upper limits from recent and historical observations
  68. GRB021211, OT at 108 s
  69. GRB021211 (HETE2493), OT at 143 sec
  70. GRB 021204: I-band Observations
  71. GRB021211 (=H2493): A Bright, Long GRB Localized by HETE-2 in Near-Real Time
  72. HETE 2493: Optical observations
  73. HETE 2493: Optical observations
  74. HETE 2493: Optical candidate
  75. GRB 021204: Optical Observations at RIKEN
  76. GRB 021125: Radio Observations
  77. IPN triangulation of GRB021206 (small error box)
  78. IPN triangulation of GRB021206 (exceptionally bright; annulus only)
  79. IPN detection of renewed activity from SGR1806-20
  80. IPN triangulation of GRB021205 (large error box)
  81. GRB 021104, GRB 021112 and GRB 021113 - Milagro GeV/TeV Observations
  82. GRB021201, BVRcIc field photometry
  83. GRB 021201, Radio Observations
  84. GRB 021201: Optical Observations
  85. GRB 021201: BOOTES simultaneous optical observations
  86. IPN triangulation of GRB021201 (short/hard burst, small error box)
  87. Radio Catalog of GRB Afterglows
  88. GRB021004, late time optical observations
  89. GRB021004 Chandra Observation
  90. IPN detection of continued SGR1900+14 activity
  91. GRB021125 refined position
  92. IPN triangulation of GRB021115 (annulus)
  93. IPN triangulation of GRB021125B (two large error boxes)
  94. IPN triangulation of GRB021119 (large error box)
  95. IPN triangulation of GRB021125B (annulus)
  96. Improved IPN error box for GRB021125
  97. IPN BURST POSITION
  98. IPN triangulation of GRB021125 (INTEGRAL BURST)
  99. GRB021125 : A long GRB localized by INTEGRAL
  100. IPN confirmation of the reactivation of SGR1900+14

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