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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"

19426 results found.

  1. GRB 021004: Optical Observations
  2. GRB 021004, SPM optical observations
  3. GRB 021004, optical observations
  4. GRB 021004 radio search
  5. GRB021004: Upper limits from recent and historical observations
  6. XRF020903, BVRI field photometry
  7. XRF020903: TNG and Asiago photometry
  8. XRF 020903: Correction to GCN 1560
  9. XRF 020903: VRI observations
  10. XRF 020903: R band observations
  11. IPN triangulation of GRB020923 (two error boxes)
  12. IPN triangulation of GRB020914B
  13. IPN annulus for GRB020914B
  14. IPN triangulation of GRB020911 (2 large error boxes)
  15. GRB 020305: HST/STIS observations
  16. Single IPN error box for GRB020904
  17. XRF 020903: optical observation at Kyoto
  18. GRB020322 : HST/STIS observations
  19. XRF 020903: Optical observations
  20. IPN triangulation of GRB020904
  21. IPN detection of a burst from SGR1900+14
  22. INTEGRAL GRBs added to GCN
  23. GRB020812: negative optical observations
  24. GRB 020812: optical observation at Kyoto University
  25. Second epoch K band imaging of GRB 020819
  26. GRB020813, Baade 6.5m data now available
  27. GRB 020813 : HST observations
  28. GRB 020812: early time optical observation at Ouda Station
  29. GRB020813: Magellan BVRI Photometry
  30. GRB 020819: Optical observations
  31. GRB020813: optical and NIR observations
  32. GRB020813: Fading X-ray Afterglow Observed with Chandra
  33. GRB020813, UBVRI field calibration
  34. Polarimetry of GRB020813: evidence for variability
  35. GRB020812: optical observations
  36. GRB020813: High-Resolution Optical Observations
  37. GRB 020812: optical observation at Bisei
  38. GRB020812: optical observations
  39. GRB020813, optical observations
  40. GRB020813, astrometric position
  41. GRB 020812 optical observation
  42. GRB 020714, optical observations
  43. GRB020801: Imaging of Suggested OT Counterpart at the Magellan
  44. HST Imaging of the Host of GRB 011121
  45. GRB020801, optical afterglow candidate
  46. GRB020331: Late-time Optical Light Curve (re-submission)
  47. GRB020331: Late-time Optical Light Curve
  48. IPN triangulation of GRB020714
  49. IPN triangulation of GRB150702
  50. GRB 020410: Discovery of Probable OT by HST
  51. IPN triangulation of GRB020708
  52. IPN triangulation of GRB020708
  53. Correction to IPN error box for GRB020706
  54. IPN triangulation of GRB020706
  55. GRB 020705: Optical observations
  56. GRB 020625: Optical observations
  57. GRB 020531: optical photometry of Chandra sources
  58. The Probable Host Galaxy of GRB/XRF 020427
  59. GRB/XRF 020427, detection of an underlying system with the VLT
  60. Gemini IR Detection of AXP 1E 2259+586 Post-Burst
  61. AXP 1E2259+586 optical observations
  62. Fading Optical Source in the Field of GRB020531
  63. GRB 020531, INT+WFC deep optical upper limits
  64. GRB020405: polarimetric observations
  65. GRB 020531, simultaneous optical observations
  66. GRB020531: Second epoch Chandra observations
  67. GRB020604, optical observations
  68. GRB020604, BVRcIc field photometry
  69. GRB020603, BVRcIc field observations
  70. GRB020531, BVRcIc field photometry
  71. GRB 020531, Radio Observations
  72. IPN triangulation of GRB020604
  73. GRB020531 Optical Observations
  74. GRB020531: Observations with the Chandra X-ray Observatory
  75. GRB020531, optical observations
  76. GRB020531: optical observations
  77. GRB020531(=H2042): Optical Observations
  78. GRB020531(=H2042): Optical Observations
  79. GRB020525, optical observations
  80. IPN triangulation of GRB020525
  81. GRB020405 field photometry at ESO
  82. GRB(XRF) 020427: X-ray afterglow with BeppoSAX
  83. XRF 020427
  84. GRB 020124: Optical observations
  85. IPN triangulation of GRB020418
  86. GRB020405: VLT observations of the OT environment
  87. GRB020405: predicted break
  88. GRB 020409: No Evidence for an Optical Afterglow
  89. GRB 020331 Kyoto observation on March 31
  90. GRB 020409
  91. BeppoSAX ALERT: possible GRB020411
  92. X-ray afterglow of GRB020321
  93. GRB020331 optical observations with RIMOTS
  94. GRB020124 optical observations with RIBOTS/RIMOTS
  95. GRB 020321: Candidate X-ray Counterparts
  96. ASM GRB candidate 020406 refined error box
  97. GRB020406(?), optical observations
  98. Short RXTE/ASM transient 020406; may be a GRB
  99. GRB020405, Radio Observations
  100. GRB 020405, U-band observations

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