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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. GRB021219 refined position with INTEGRAL
  2. VLT spectra of GRB 021211 revisited
  3. GRB021219: a long GRB localized by INTEGRAL
  4. GRB021211: APO optical observations
  5. IPN detection of continued activity from SGR1806-20
  6. IPN triangulation of GRB021215 (large error box)
  7. IPN triangulation of GRB021214 (annulus)
  8. XRF 020903 : HST observations
  9. GRB 021201: Optical Observations
  10. GRB 021211, optical observations
  11. GRB 021211: CTIO observations
  12. GRB021211: Measurement of Early Time Afterglow
  13. VLT spectrum of GRB 021211
  14. IPN triangulation of GRB021211B (two large error boxes)
  15. GRB 021211: early break in light curve
  16. GRB021211, BVRI field photometry
  17. GRB021211: Optical observations in CrAO
  18. GRB 021211, IR observations
  19. GRB 021211, optical observations
  20. GRB 021211: Optical Observations
  21. GRB021211: Kiso Observations
  22. GRB021204: Kiso Observations
  23. GRB 021201, optical observations
  24. GRB 021211: Radio Observations
  25. GRB021211: Optical observations
  26. GRB 021201 (short/hard), NOT observations
  27. SUB-MM SEARCH FOR GRB 021211
  28. Chandra observation of the IPN error box of GRB021201 (short/hard)
  29. GRB 021211 Milagro GeV/TeV Observations
  30. GRB 021211, R- and I-band observations
  31. GRB021211 - Upper limits from recent and historical observations
  32. GRB021211, OT at 108 s
  33. GRB021211 (HETE2493), OT at 143 sec
  34. GRB 021204: I-band Observations
  35. GRB021211 (=H2493): A Bright, Long GRB Localized by HETE-2 in Near-Real Time
  36. HETE 2493: Optical observations
  37. HETE 2493: Optical observations
  38. HETE 2493: Optical candidate
  39. GRB 021204: Optical Observations at RIKEN
  40. GRB 021125: Radio Observations
  41. IPN triangulation of GRB021206 (small error box)
  42. IPN triangulation of GRB021206 (exceptionally bright; annulus only)
  43. IPN detection of renewed activity from SGR1806-20
  44. IPN triangulation of GRB021205 (large error box)
  45. GRB 021104, GRB 021112 and GRB 021113 - Milagro GeV/TeV Observations
  46. GRB021201, BVRcIc field photometry
  47. GRB 021201, Radio Observations
  48. GRB 021201: Optical Observations
  49. GRB 021201: BOOTES simultaneous optical observations
  50. IPN triangulation of GRB021201 (short/hard burst, small error box)
  51. Radio Catalog of GRB Afterglows
  52. GRB021004, late time optical observations
  53. GRB021004 Chandra Observation
  54. IPN detection of continued SGR1900+14 activity
  55. GRB021125 refined position
  56. IPN triangulation of GRB021115 (annulus)
  57. IPN triangulation of GRB021125B (two large error boxes)
  58. IPN triangulation of GRB021119 (large error box)
  59. IPN triangulation of GRB021125B (annulus)
  60. Improved IPN error box for GRB021125
  61. IPN BURST POSITION
  62. IPN triangulation of GRB021125 (INTEGRAL BURST)
  63. GRB021125 : A long GRB localized by INTEGRAL
  64. IPN confirmation of the reactivation of SGR1900+14
  65. IPN detection of possible reactivation of SGR1900+14
  66. GRB021113, SPI ACS observation
  67. IPN triangulation of GRB021119 (annulus)
  68. GRB 021112: Afterglow or Variable Star?
  69. GRB021113: optical observations at Bisei
  70. GRB 021113: Evidence for a Dark Optical Afterglow
  71. GRB 021112, Radio Observations
  72. GRB021112, BVRI field photometry
  73. GRB 021112: Variable Source in R-band search
  74. GRB021112: Optical Observations
  75. GRB021113: Kiso Observations
  76. IPN triangulation of GRB021109 (portion of annulus)
  77. IPN triangulation of GRB021113 (=H2449; annulus)
  78. IPN triangulation of GRB021108 (CORRECTION; TWO LARGE ERROR BOXES)
  79. GRB 021113: Optical observations
  80. GRB 021112: RAPTOR Observations
  81. GRB 021113: Optical Observations
  82. GRB 021113: Optical Observations
  83. GRB021113 (=H2449): A Long GRB Localized by HETE
  84. GRB 021112: Optical Observations
  85. GRB 021112: R-band search
  86. IPN triangulation of GRB021108 (large error box)
  87. GRB021112 (=H2448): A Long GRB Localized by HETE
  88. GRB 021016: Optical Observations
  89. IPN triangulation of GRB021109 (annulus)
  90. IPN triangulation of GRB021108 (annulus)
  91. GRB021004: Near infrared spectroscopy
  92. GRB021104: Optical Observations
  93. IPN triangulation of GRB021104 (annulus)
  94. GRB021104(=H2434): A Long, X-Ray-Rich GRB Localized by HETE
  95. IPN triangulation of bursts from SGR1900+14, November 1-2, 2002
  96. SGR1900+14 activity, November 2-4, 2002
  97. Spectropolarimetry of GRB021004
  98. GRB021104: Optical observations
  99. GRB021104: optical observations
  100. GRB021104: Candidate present in DSS

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