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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').
Advanced Search

To narrow the search results, use advanced search syntax. This allows for specifying which circular field to search (submitter, subject, and/or body). For additional information, refer to the advanced search documentation.

Advanced Search Examples (click to copy):

subject:"Swift"
body:"GRB"
submitter:"Judith Racusin"

20512 results found.

  1. XRF 020903, optical observations
  2. GRB020813: High-resolution optical spectroscopy
  3. GRB020819: optical observations at Bisei
  4. GRB020812: negative optical observations
  5. GRB020813, Baade 6.5m data now available
  6. GRB 020813 : HST observations
  7. Confirming no variability for GRB02081
  8. GRB020819 : Optical observations at KISO
  9. GRB020813: VRI Decay Slopes
  10. GRB020813: Magellan BVRI Photometry
  11. GRB 020819: Optical observations
  12. K band observation of GRB 020819
  13. GRB020819: optical observations
  14. HETE 2275: Optical observations
  15. GRB020813: optical and NIR observations
  16. GRB020813: Fading X-ray Afterglow Observed with Chandra
  17. GRB020813: optical observations at Bisei
  18. GRB020812: NIR observations
  19. Polarimetry of GRB020813: evidence for variability
  20. GRB020813 IRAM millimeter observations
  21. GRB020812: optical observations
  22. GRB020813: High-Resolution Optical Observations
  23. GRB 020812: optical observation at Bisei
  24. GRB020813: optical observations; possible host galaxy
  25. GRB 020813, radio detection
  26. GRB 020812 : optical afterglow candidate
  27. GRB020813, optical observations
  28. Millimeter observation of GRB 020813
  29. GRB020812: optical observations
  30. GRB 020813 : KISO multiband optical observations
  31. GRB020813, optical observations
  32. GRB 020813 Afterglow Observations; Possible break
  33. GRB 020813 multiband optical observations
  34. GRB020813: Fading of Candidate OT
  35. GRB 020715, optical observations
  36. GRB 020714, optical observations
  37. GRB020801: Imaging of Suggested OT Counterpart at the Magellan
  38. GRB020801: Candidate OT present in DSS
  39. GRB020801, optical afterglow candidate
  40. GRB020331: Late-time Optical Light Curve (re-submission)
  41. GRB020331: Late-time Optical Light Curve
  42. GRB 020405: HST observations reveal red bump
  43. GRB 020410: Discovery of Probable OT by HST
  44. GRB 020124, HST observations of the fading afterglow
  45. GRB 020705: Optical observations
  46. GRB 020625, optical observations
  47. GRB 020625: Optical observations
  48. GRB 020531: optical photometry of Chandra sources
  49. HETE #2081: Optical observations
  50. The Probable Host Galaxy of GRB/XRF 020427
  51. Gemini IR Detection of AXP 1E 2259+586 Post-Burst
  52. SGR-like X-ray Bursts from AXP 1E 2259+586: follow-up
  53. AXP 1E2259+586 optical observations
  54. Fading Optical Source in the Field of GRB020531
  55. GRB 020531, INT+WFC deep optical upper limits
  56. SGR-like Bursts from the AXP 1E 2259+586
  57. GRB020405: polarimetric observations
  58. GRB 020531, simultaneous optical observations
  59. GRB 020604, optical observations
  60. GRB 020531/Candidate Redshift
  61. GRB020531: Second epoch Chandra observations
  62. GRB020604, optical observations
  63. GRB020603, BVRcIc field observations
  64. GRB020531 Optical observations with TAROT
  65. GRB020531 Optical observations with TAROT
  66. GRB 020418, optical/near-IR observations
  67. GRB 020531, Radio Observations
  68. GRB020531 Optical Observations
  69. GRB020531: Observations with the Chandra X-ray Observatory
  70. GRB 020603: Optical Observations
  71. GRB020531: Upper Limit for Detection of Two TAROT Sources
  72. GRB 020603: Optical observations
  73. GRB 020531 optical observations with TAROT
  74. GRB020531, optical observations
  75. GRB020531: optical observations
  76. GRB020531(=H2042): Optical Observations
  77. GRB020531(=H2042): Optical Observations
  78. GRB020531: Optical observations
  79. GRB 020525: Optical Observations
  80. GRB020525, optical observations
  81. HETE Observations of GX354-0 (= MXB1728-34, so-called "Slow
  82. XRF020427: Chandra Identification of a Likely X-ray Counterpart
  83. GRB/XRF 020427, Radio Observations
  84. XRF020427: Chandra Observations and Candidate X-ray Counterparts
  85. GRB020321 : Optical observations.
  86. GRB020427 BeppoSAX NFI Observation
  87. XRF 020427
  88. GRB020331: Third Epoch and Revised Second Epoch Optical
  89. The end of BSAX GRB activities
  90. GRB 020410, Radio Observations
  91. GRB 020418: Optical observations
  92. GRB 020124: Optical observations
  93. GRB 020418: Optical observations
  94. GRB020405: VLT observations of the OT environment
  95. GRB020410: BeppoSAX NFI observations refined analysis
  96. GRB 020409: Optical Observations
  97. GRB 020409, 2-nd epoch optical observations at Terskol.
  98. GRB020405: predicted break
  99. GRB 020409: Optical observations
  100. GRB 020409, 2nd epoch optical observations

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