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

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