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

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