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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. GRB021201, BVRcIc field photometry
  2. GRB 021201, Radio Observations
  3. GRB 021201: Optical Observations
  4. GRB 021201: BOOTES simultaneous optical observations
  5. IPN triangulation of GRB021201 (short/hard burst, small error box)
  6. Radio Catalog of GRB Afterglows
  7. GRB021004, late time optical observations
  8. GRB021004 Chandra Observation
  9. IPN detection of continued SGR1900+14 activity
  10. GRB021125 refined position
  11. IPN triangulation of GRB021115 (annulus)
  12. IPN triangulation of GRB021125B (two large error boxes)
  13. IPN triangulation of GRB021119 (large error box)
  14. IPN triangulation of GRB021125B (annulus)
  15. Improved IPN error box for GRB021125
  16. IPN BURST POSITION
  17. IPN triangulation of GRB021125 (INTEGRAL BURST)
  18. GRB021125 : A long GRB localized by INTEGRAL
  19. IPN confirmation of the reactivation of SGR1900+14
  20. IPN detection of possible reactivation of SGR1900+14
  21. GRB021113, SPI ACS observation
  22. IPN triangulation of GRB021119 (annulus)
  23. GRB 021112: Afterglow or Variable Star?
  24. GRB021113: optical observations at Bisei
  25. GRB 021113: Evidence for a Dark Optical Afterglow
  26. GRB 021112, Radio Observations
  27. GRB021112, BVRI field photometry
  28. GRB 021112: Variable Source in R-band search
  29. GRB021112: Optical Observations
  30. GRB021113: Kiso Observations
  31. IPN triangulation of GRB021109 (portion of annulus)
  32. IPN triangulation of GRB021113 (=H2449; annulus)
  33. IPN triangulation of GRB021108 (CORRECTION; TWO LARGE ERROR BOXES)
  34. GRB 021113: Optical observations
  35. GRB 021112: RAPTOR Observations
  36. GRB 021113: Optical Observations
  37. GRB 021113: Optical Observations
  38. GRB021113 (=H2449): A Long GRB Localized by HETE
  39. GRB 021112: Optical Observations
  40. GRB 021112: R-band search
  41. IPN triangulation of GRB021108 (large error box)
  42. GRB021112 (=H2448): A Long GRB Localized by HETE
  43. GRB 021016: Optical Observations
  44. IPN triangulation of GRB021109 (annulus)
  45. IPN triangulation of GRB021108 (annulus)
  46. GRB021004: Near infrared spectroscopy
  47. GRB021104: Optical Observations
  48. IPN triangulation of GRB021104 (annulus)
  49. GRB021104(=H2434): A Long, X-Ray-Rich GRB Localized by HETE
  50. IPN triangulation of bursts from SGR1900+14, November 1-2, 2002
  51. SGR1900+14 activity, November 2-4, 2002
  52. Spectropolarimetry of GRB021004
  53. GRB021104: Optical observations
  54. GRB021104: optical observations
  55. GRB021104: Candidate present in DSS
  56. GRB021104: possible optical afterglow
  57. IPN triangulation of GRB021102 (annulus)
  58. Detection of activity from SGR 1900+14 with the RXTE/PCA
  59. IPN triangulation of a burst from SGR1900+14 on November 01, 2002
  60. IPN triangulation of a burst from SGR1900+14 on October 29 2002
  61. IPN triangulation of GRB021025 (portion of annulus)
  62. IPN triangulation of GRB021027 (single large error box)
  63. GRB021004, late-time optical observations
  64. IPN triangulation of GRB021027 (two large error boxes)
  65. GRB 021023: Infrared Imaging
  66. IPN triangulation of GRB021027 (annulus)
  67. GRB 021023: Curious K-band Source(s) Just Outside of IPN Localization
  68. IPN triangulation of GRB021025 (annulus)
  69. IPN triangulation of SGR1900+14, October 22 2002
  70. GRB 021004: optical observations
  71. IPN triangulation of GRB021023 (small error boc)
  72. GRB021004: Optical Observations
  73. GRB 020813; likely host galaxy.
  74. IPN triangulation of GRB021020 (smaller error box)
  75. GRB021021(=XRF 021021): An X-ray Flash Localized by HETE
  76. IPN triangulation of GRB021020
  77. GRB 021008, radio observations
  78. GRB 021016, optical observations
  79. GRB 021004: VRI observations at TNG: possible break
  80. GRB021016, optical observations
  81. SGR1900+14: burst on October 10 2002
  82. GRB 021008, optical observations
  83. GRB021016(=H2397): A Long GRB Localized by HETE
  84. IPN triangulation of GRB021016 (area corrected)
  85. IPN triangulation of GRB021016 (small error box)
  86. GRB021004: Optical Observations
  87. IPN triangulation of GRB021014 (large error box)
  88. IPN triangulation of GRB021013 (single error box)
  89. GRB 021004: optical spectroscopy on Oct 11
  90. IPN triangulation of GRB021013 (two small error boxes)
  91. GRB021004: High-resolution optical spectroscopy
  92. IPN triangulation of GRB021013 (annulus)
  93. XRF 020903: flattening of the optical light curve.
  94. GRB021004, UBVRcIc field photometry update
  95. IPN triangulation of GRB021008 (single error box)
  96. GRB021004: Optical Observations
  97. GRB 021004 submm observations
  98. IPN triangulation of GRB021008B (annulus)
  99. IPN triangulation of GRB021008 (two small error boxes)
  100. GRB021004 Chandra HETG Observations

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