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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. GRB030115: R-band observations at Asiago
  2. GRB030115: TAROT optical observations
  3. GRB 021211: VLT spectrum
  4. GRB 030115: APO Optical Observations
  5. GRB 030115, no optical candidate
  6. GRB 030115, optical observations
  7. GRB 030115, optical candidate
  8. Possible GRB030113 seen by SPI ACS
  9. Probable GRB030112B seen by SPI ACS
  10. Probable GRB030112 seen by SPI ACS
  11. Information about where HETE will be pointing
  12. Possible GRB030111 seen by SPI ACS
  13. Possible GRB030110b seen by SPI ACS
  14. Possible GRB 030110 seen by SPI ACS
  15. IPN triangulation of GRB030109 (annulus)
  16. IPN triangulation of GRB030105 (large error box)
  17. IPN triangulation of GRB030102B (refined localization - portion of annulus)
  18. Possible GRB 20030109 seen by SPI ACS
  19. IPN triangulation of GRB030102A - correction to peak flux
  20. IPN triangulation of GRB030102B (portion of annulus)
  21. IPN triangulation of GRB030102A (large error box)
  22. Coronas-F -Wind triangulation of GRB030102
  23. Possible GRB20030107 seen by SPI-ACS
  24. Possible GRB 20030105 seen by SPI ACS
  25. IPN triangulation of GRB030102 (annulus)
  26. GRB on 20030102 seen by SPI-ACS
  27. VLT spectroscopy of the probable host of GRB 021211
  28. GRB on 20030101 seen by SPI-ACS
  29. IPN triangulation of GRB030101 (two large error boxes)
  30. GRB021226
  31. GRB 021211: Probable Host and Underlying Supernova
  32. GRB 021226 registration by Helicon/Coronas-F
  33. Probable GRB in INTEGRAL SPI-ACS
  34. IPN triangulation of GRB021223 (two large error boxes)
  35. GRB021211, radio observations
  36. GRB 021112: Evidence for Another Dark Optical Afterglow
  37. GRB 021219: OSN optical observations
  38. GRB021219: Radio Observations
  39. GRB021219, optical observations
  40. IPN triangulation of GRB021219 - CORRECTION
  41. IPN triangulation of GRB021219
  42. GRB021219, optical observation by MASTER
  43. GRB021219: Correction to GCN 1766
  44. GRB021219 refined position with INTEGRAL
  45. VLT spectra of GRB 021211 revisited
  46. GRB021219: a long GRB localized by INTEGRAL
  47. GRB021211: APO optical observations
  48. IPN detection of continued activity from SGR1806-20
  49. IPN triangulation of GRB021215 (large error box)
  50. IPN triangulation of GRB021214 (annulus)
  51. XRF 020903 : HST observations
  52. GRB 021201: Optical Observations
  53. GRB 021211, optical observations
  54. GRB 021211: CTIO observations
  55. GRB021211: Measurement of Early Time Afterglow
  56. VLT spectrum of GRB 021211
  57. IPN triangulation of GRB021211B (two large error boxes)
  58. GRB 021211: early break in light curve
  59. GRB021211, BVRI field photometry
  60. GRB021211: Optical observations in CrAO
  61. GRB 021211, IR observations
  62. GRB 021211, optical observations
  63. GRB 021211: Optical Observations
  64. GRB021211: Kiso Observations
  65. GRB021204: Kiso Observations
  66. GRB 021201, optical observations
  67. GRB 021211: Radio Observations
  68. GRB021211: Optical observations
  69. GRB 021201 (short/hard), NOT observations
  70. SUB-MM SEARCH FOR GRB 021211
  71. Chandra observation of the IPN error box of GRB021201 (short/hard)
  72. GRB 021211 Milagro GeV/TeV Observations
  73. GRB 021211, R- and I-band observations
  74. GRB021211 - Upper limits from recent and historical observations
  75. GRB021211, OT at 108 s
  76. GRB021211 (HETE2493), OT at 143 sec
  77. GRB 021204: I-band Observations
  78. GRB021211 (=H2493): A Bright, Long GRB Localized by HETE-2 in Near-Real Time
  79. HETE 2493: Optical observations
  80. HETE 2493: Optical observations
  81. HETE 2493: Optical candidate
  82. GRB 021204: Optical Observations at RIKEN
  83. GRB 021125: Radio Observations
  84. IPN triangulation of GRB021206 (small error box)
  85. IPN triangulation of GRB021206 (exceptionally bright; annulus only)
  86. IPN detection of renewed activity from SGR1806-20
  87. IPN triangulation of GRB021205 (large error box)
  88. GRB 021104, GRB 021112 and GRB 021113 - Milagro GeV/TeV Observations
  89. GRB021201, BVRcIc field photometry
  90. GRB 021201, Radio Observations
  91. GRB 021201: Optical Observations
  92. GRB 021201: BOOTES simultaneous optical observations
  93. IPN triangulation of GRB021201 (short/hard burst, small error box)
  94. Radio Catalog of GRB Afterglows
  95. GRB021004, late time optical observations
  96. GRB021004 Chandra Observation
  97. IPN detection of continued SGR1900+14 activity
  98. GRB021125 refined position
  99. IPN triangulation of GRB021115 (annulus)
  100. IPN triangulation of GRB021125B (two large error boxes)

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