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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"

6790 results found.

  1. GRB020531, optical observations
  2. HST detection of the likely host galaxy of GRB 020124
  3. XRF020427: Chandra Observations and Candidate X-ray Counterparts
  4. GRB 020418: Optical observations
  5. GRB 020321: Candidate X-ray Counterparts
  6. GRB 020331: Candidate Optical Afterglow
  7. GRB 020331: NIR Observations
  8. GRB 020322: Optical Sources and Improved Astrometry
  9. GRB 020317: Optical observations
  10. GRB020127: Comparison of Chandra Epochs and Identification of Possible Counterparts
  11. GRB 020127, I-band observations starting 3.14-hr after the event
  12. VLT observations of GRB 020124: The fading optical/near-infrared afterglow
  13. GRB optical counterpart candidate in GCN 1217 is M dwarf
  14. GRB 011121: NIR observations, host galaxy?
  15. GRB 011121: Detection of Bright IR Counterpart
  16. Optical observation of SGR 1806-20 at the 6-m SAO telescope
  17. GRB001109, Host Galaxy Spectroscopic Observations
  18. SGR1806-20: Localization by HETE
  19. SGR 1900+14 : RXTE observations
  20. GRB 010222: Keck Spectroscopy
  21. GRB 010222, Decay Slope Confirmed
  22. Redshift of the Optical Transient of GRB010222
  23. GRB010220, Radio and Optical Observations
  24. GRB010214 Optical Observation
  25. GRB 001204: Ks observations
  26. GRB 001212 Optical Observation
  27. GRB 001212 possible OA in 2MASS
  28. GRB 001212 possible OA
  29. GRB 001105, further optical observations
  30. GRB001120, optical observations
  31. Optical/NIR observations of GRB001109
  32. GRB 001109: deep JHK upper limits
  33. GRB 001105, R-band observation
  34. V,R,I band observations of GRB000926
  35. The Likely Optical/Infrared Afterglow of GRB 001011
  36. GRB000911, Radio and Optical observations
  37. SGR 1806-20 burst activity
  38. GRB000630: Optical observations
  39. GRB000615, R-band photometry
  40. GRB 000418: Detection of the Host Galaxy
  41. X-ray Afterglow of GRB 000529
  42. GRB 000528 Optical Observations
  43. BATSE observations of FXT/GRB 000416 = 1SAXJ1715.0-7134
  44. GRB000301C, Radio observations
  45. GRB000301C, Radio observations
  46. GRB 000210: BATSE Observations
  47. BATSE GRB trigger criteria changed
  48. BATSE Observations of GRB000115
  49. GRB 991216: Updated BATSE parameters
  50. IR observations of GRB991216
  51. GRB 991216 Radio Observations
  52. GRB 991208 SAO-RAS Spectroscopy
  53. GRB 991208 Keck Spectroscopy
  54. GRB 991216: Extremely bright BATSE burst
  55. GRB991208, optical observations
  56. GRB991106: BeppoSAX/BATSE results
  57. BeppoSAX NFI Observation of GRB991106
  58. GRB 991105: BATSE Observations
  59. GRB 991106 Optical Observations
  60. GRB991014 BATSE Observations
  61. BATSE GRB trigger criteria
  62. GRB990806: BATSE Observations
  63. Late-time HST/STIS Observations of GRB 990510
  64. X-ray/GRB 1SAX J0835.9+5118, BATSE Observation
  65. GRB 990510: BATSE Observations
  66. GRB 990510 Optical Observations
  67. GRB 990506: BATSE Observations
  68. GRB 990506, Optical Observations
  69. GRB 990506 optical observations
  70. GRB 990506 optical observations
  71. GRB 990316 optical observations
  72. GRB990123, 15-GHz limits
  73. GRB 990123: BATSE Observations
  74. GRB 990123 Optical Follow-up
  75. GRB981220, Optical Observations
  76. GRB 981220:Optical Observations
  77. GRB 981226 - Infrared Observations
  78. GRB 980326/Host Galaxy
  79. GRB 980923 BATSE Observations
  80. GRB980703, Host galaxy multicolor photometry
  81. GRB 980703: BATSE Observations
  82. GRB 980613: BATSE Observations
  83. SGR1900+14
  84. SGR1900+14
  85. GRB980519 BATSE Observations
  86. BATSE on-board GRB trigger change
  87. GRB980425 BATSE observations
  88. GRB980329
  89. GRB 971214: KPNO Optical Observations
  90. GRB 970228: Keck/LRIS Optical Observations

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