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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. K band observation of GRB 020819
  2. GRB020819: optical observations
  3. GRB020819(=H2275): A Long Burst Localized by the HETE WXM and SXC
  4. IPN triangulation of GRB020819 (HETE 2275)
  5. HETE 2275: Optical observations
  6. GRB020813: optical and NIR observations
  7. GRB020813: Fading X-ray Afterglow Observed with Chandra
  8. GRB020813, UBVRI field calibration
  9. GRB 020813: addendum to GCN 1498
  10. GRB020813: optical observations at Bisei
  11. GRB020813: V-band decay slope
  12. GRB020812: NIR observations
  13. Polarimetry of GRB020813: evidence for variability
  14. GRB020813 IRAM millimeter observations
  15. GRB020812: optical observations
  16. GRB020813: High-Resolution Optical Observations
  17. GRB020813(=H2262): Revised Localization with HETE SXC
  18. GRB 020812: optical observation at Bisei
  19. GRB020813: Early Time Magnitude
  20. GRB020813: optical observations; possible host galaxy
  21. GRB 020813, radio detection
  22. GRB 020812 : optical afterglow candidate
  23. GRB020813, optical observations
  24. Millimeter observation of GRB 020813
  25. GRB020812: optical observations
  26. GRB 020813 : KISO multiband optical observations
  27. GRB020813, optical observations
  28. IPN error box for GRB020813
  29. IPN triangulation of GRB020813
  30. GRB020812: possible afterglow candidate
  31. Early Time Limits for GRB020813
  32. GRB020812: possible afterglow candidate
  33. GRB020813, astrometric position
  34. Spectropolarimetry of GRB 020813
  35. GRB 020813 Afterglow Observations; Possible break
  36. GRB 020813: Absorption redshift
  37. GRB 020813 multiband optical observations
  38. GRB020813: optical afterglow
  39. GRB020813: Fading of Candidate OT
  40. GRB020813(=H2262): A Long, Bright Burst Localized by HETE in Near-Real Time
  41. GRB020813: Candidate Optical Afterglow
  42. GRB 020812 optical observation
  43. GRB020812(=H2257): A Long Burst Localized by HETE in Near-Real Time
  44. GRB 020715, optical observations
  45. GRB 020714, optical observations
  46. GRB020801: Imaging of Suggested OT Counterpart at the Magellan
  47. GRB020801: Candidate OT present in DSS
  48. HST Imaging of the Host of GRB 011121
  49. GRB020801, optical afterglow candidate
  50. Further refinement to IPN error box for GRB020531
  51. GRB020331: Late-time Optical Light Curve (re-submission)
  52. GRB020331: Late-time Optical Light Curve
  53. GRB 020405: HST observations reveal red bump
  54. IPN triangulation of GRB020714
  55. IPN triangulation of GRB020715 (=GRB150702)
  56. IPN triangulation of GRB020714
  57. IPN triangulation of GRB150702
  58. GRB 020410: Discovery of Probable OT by HST
  59. GRB 020124, HST observations of the fading afterglow
  60. IPN triangulation of GRB020708
  61. IPN triangulation of GRB020708
  62. IPN error box for GRB020706
  63. Correction to IPN error box for GRB020706
  64. IPN triangulation of GRB020706
  65. GRB 020705: Optical observations
  66. GRB 020625, optical observations
  67. GRB 020625: Optical observations
  68. GRB 020531: optical photometry of Chandra sources
  69. GRB020625 (=H2081): A Long Burst Localized by HETE
  70. HETE #2081: Optical observations
  71. The Probable Host Galaxy of GRB/XRF 020427
  72. GRB/XRF 020427, detection of an underlying system with the VLT
  73. Gemini IR Detection of AXP 1E 2259+586 Post-Burst
  74. SGR-like X-ray Bursts from AXP 1E 2259+586: follow-up
  75. AXP 1E2259+586: quasi-simultaneous optical observation
  76. AXP 1E2259+586 optical observations
  77. Fading Optical Source in the Field of GRB020531
  78. GRB 020531, INT+WFC deep optical upper limits
  79. SGR-like Bursts from the AXP 1E 2259+586
  80. GRB020405: polarimetric observations
  81. GRB 020531, simultaneous optical observations
  82. GRB 020604, optical observations
  83. GRB 020531/Candidate Redshift
  84. GRB020531: Detection of Candidate Host Galaxy
  85. GRB020531: Second epoch Chandra observations
  86. GRB020604, optical observations
  87. GRB020604, BVRcIc field photometry
  88. GRB020603, BVRcIc field observations
  89. GRB020531, BVRcIc field photometry
  90. GRB020531 Optical observations with TAROT
  91. GRB020531 Optical observations with TAROT
  92. GRB 020418, optical/near-IR observations
  93. GRB 020531, Radio Observations
  94. IPN triangulation of GRB020604
  95. GRB020531 Optical Observations
  96. GRB020531: Observations with the Chandra X-ray Observatory
  97. GRB 020603: Optical Observations
  98. GRB 020603, R-band observation
  99. Correction to IPN triangulation of GRB020603 (possible short/hard burst)
  100. GRB020531: Upper Limit for Detection of Two TAROT Sources

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