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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"

26011 results found.

  1. XRF 020903: Supernova
  2. IPN triangulation of GRB020923 (two error boxes)
  3. IPN triangulation of GRB020914B
  4. IPN triangulation of GRB020911 (2 large error boxes)
  5. GRB 020305: HST/STIS observations
  6. Confirmation of IPN error box for GRB020910
  7. IPN triangulation of GRB020910
  8. IPN GCN Circulars now to be issued without restriction
  9. Single IPN error box for GRB020904
  10. XRF 020903: optical observation at Kyoto
  11. GRB020322 : HST/STIS observations
  12. XRF 020903: Optical observations
  13. IPN triangulation of GRB020904
  14. INTEGRAL GRBs added to GCN
  15. SGR1900+14 burst localized by HETE
  16. GRB020813: High-resolution optical spectroscopy
  17. GRB020812: negative optical observations
  18. GRB 020812: optical observation at Kyoto University
  19. Second epoch K band imaging of GRB 020819
  20. GRB 020813 : HST observations
  21. GRB 020812: early time optical observation at Ouda Station
  22. GRB020813: Magellan BVRI Photometry
  23. GRB 020819: Optical observations
  24. K band observation of GRB 020819
  25. GRB020813: optical and NIR observations
  26. GRB020813: Fading X-ray Afterglow Observed with Chandra
  27. GRB020813, UBVRI field calibration
  28. GRB020812: NIR observations
  29. Polarimetry of GRB020813: evidence for variability
  30. GRB020813 IRAM millimeter observations
  31. GRB020812: optical observations
  32. GRB020813: High-Resolution Optical Observations
  33. GRB 020812: optical observation at Bisei
  34. GRB020813: Early Time Magnitude
  35. Millimeter observation of GRB 020813
  36. GRB020812: optical observations
  37. GRB 020813 : KISO multiband optical observations
  38. GRB020813, optical observations
  39. IPN error box for GRB020813
  40. GRB020813, astrometric position
  41. Spectropolarimetry of GRB 020813
  42. GRB 020812 optical observation
  43. GRB020812(=H2257): A Long Burst Localized by HETE in Near-Real Time
  44. GRB020801: Imaging of Suggested OT Counterpart at the Magellan
  45. HST Imaging of the Host of GRB 011121
  46. GRB020801, optical afterglow candidate
  47. GRB020331: Late-time Optical Light Curve (re-submission)
  48. GRB020331: Late-time Optical Light Curve
  49. IPN triangulation of GRB020714
  50. IPN triangulation of GRB020715 (=GRB150702)
  51. IPN triangulation of GRB020714
  52. IPN triangulation of GRB150702
  53. GRB 020410: Discovery of Probable OT by HST
  54. GRB 020124, HST observations of the fading afterglow
  55. IPN triangulation of GRB020708
  56. IPN triangulation of GRB020708
  57. Correction to IPN error box for GRB020706
  58. IPN triangulation of GRB020706
  59. GRB 020705: Optical observations
  60. GRB 020625, optical observations
  61. GRB 020625: Optical observations
  62. GRB 020531: optical photometry of Chandra sources
  63. GRB020625 (=H2081): A Long Burst Localized by HETE
  64. The Probable Host Galaxy of GRB/XRF 020427
  65. GRB/XRF 020427, detection of an underlying system with the VLT
  66. Gemini IR Detection of AXP 1E 2259+586 Post-Burst
  67. AXP 1E2259+586 optical observations
  68. Fading Optical Source in the Field of GRB020531
  69. GRB 020531, INT+WFC deep optical upper limits
  70. SGR-like Bursts from the AXP 1E 2259+586
  71. GRB020405: polarimetric observations
  72. GRB 020531, simultaneous optical observations
  73. GRB 020531/Candidate Redshift
  74. GRB020531: Detection of Candidate Host Galaxy
  75. GRB020531: Second epoch Chandra observations
  76. GRB020604, optical observations
  77. GRB020604, BVRcIc field photometry
  78. GRB020603, BVRcIc field observations
  79. GRB020531, BVRcIc field photometry
  80. GRB020531 Optical Observations
  81. GRB020531: Observations with the Chandra X-ray Observatory
  82. GRB020531, optical observations
  83. GRB020531: optical observations
  84. GRB020531(=H2042): Optical Observations
  85. GRB020531(=H2042): Optical Observations
  86. GRB020531: Optical observations
  87. GRB020531(=H2042): A Short, Hard Burst Localized by HETE
  88. GRB020525, optical observations
  89. HETE Observations of GX354-0 (= MXB1728-34, so-called "Slow
  90. XRF020427: Chandra Identification of a Likely X-ray Counterpart
  91. HST detection of the likely host galaxy of GRB 020124
  92. GRB020405 field photometry at ESO
  93. XRF020427: Chandra Observations and Candidate X-ray Counterparts
  94. GRB(XRF) 020427: X-ray afterglow with BeppoSAX
  95. GRB020321 : Optical observations.
  96. XRF 020427
  97. GRB 020124: Optical observations
  98. IPN triangulation of GRB020418
  99. GRB020405: VLT observations of the OT environment
  100. IPN triangulation of GRB020413

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