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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"

6094 results found.

  1. SGR-like Bursts from the AXP 1E 2259+586
  2. GRB 020531/Candidate Redshift
  3. GRB 020418, optical/near-IR observations
  4. GRB 020603, R-band observation
  5. GRB020531, optical observations
  6. HST detection of the likely host galaxy of GRB 020124
  7. XRF020427: Chandra Observations and Candidate X-ray Counterparts
  8. GRB 020418: Optical observations
  9. GRB 020321: Candidate X-ray Counterparts
  10. GRB 020331: Candidate Optical Afterglow
  11. GRB 020331: NIR Observations
  12. GRB 020322: Optical Sources and Improved Astrometry
  13. GRB 020317: Optical observations
  14. GRB020127: Comparison of Chandra Epochs and Identification of Possible Counterparts
  15. GRB 020127, I-band observations starting 3.14-hr after the event
  16. VLT observations of GRB 020124: The fading optical/near-infrared afterglow
  17. GRB optical counterpart candidate in GCN 1217 is M dwarf
  18. GRB 011121: NIR observations, host galaxy?
  19. GRB 011121: Detection of Bright IR Counterpart
  20. Optical observation of SGR 1806-20 at the 6-m SAO telescope
  21. GRB001109, Host Galaxy Spectroscopic Observations
  22. SGR1806-20: Localization by HETE
  23. SGR 1900+14 : RXTE observations
  24. GRB 010222: Keck Spectroscopy
  25. GRB 010222, Decay Slope Confirmed
  26. Redshift of the Optical Transient of GRB010222
  27. GRB010220, Radio and Optical Observations
  28. GRB010214 Optical Observation
  29. GRB 001204: Ks observations
  30. GRB 001212 Optical Observation
  31. GRB 001212 possible OA in 2MASS
  32. GRB 001212 possible OA
  33. GRB 001105, further optical observations
  34. GRB001120, optical observations
  35. Optical/NIR observations of GRB001109
  36. GRB 001109: deep JHK upper limits
  37. GRB 001105, R-band observation
  38. V,R,I band observations of GRB000926
  39. The Likely Optical/Infrared Afterglow of GRB 001011
  40. GRB000911, Radio and Optical observations
  41. SGR 1806-20 burst activity
  42. GRB000630: Optical observations
  43. GRB000615, R-band photometry
  44. GRB 000418: Detection of the Host Galaxy
  45. X-ray Afterglow of GRB 000529
  46. GRB 000528 Optical Observations
  47. BATSE observations of FXT/GRB 000416 = 1SAXJ1715.0-7134
  48. GRB000301C, Radio observations
  49. GRB000301C, Radio observations
  50. GRB 000210: BATSE Observations
  51. BATSE GRB trigger criteria changed
  52. BATSE Observations of GRB000115
  53. GRB 991216: Updated BATSE parameters
  54. IR observations of GRB991216
  55. GRB 991216 Radio Observations
  56. GRB 991208 SAO-RAS Spectroscopy
  57. GRB 991208 Keck Spectroscopy
  58. GRB 991216: Extremely bright BATSE burst
  59. GRB991208, optical observations
  60. GRB991106: BeppoSAX/BATSE results
  61. BeppoSAX NFI Observation of GRB991106
  62. GRB 991105: BATSE Observations
  63. GRB 991106 Optical Observations
  64. GRB991014 BATSE Observations
  65. BATSE GRB trigger criteria
  66. GRB990806: BATSE Observations
  67. Late-time HST/STIS Observations of GRB 990510
  68. X-ray/GRB 1SAX J0835.9+5118, BATSE Observation
  69. GRB 990510: BATSE Observations
  70. GRB 990510 Optical Observations
  71. GRB 990506: BATSE Observations
  72. GRB 990506, Optical Observations
  73. GRB 990506 optical observations
  74. GRB 990506 optical observations
  75. GRB 990316 optical observations
  76. GRB990123, 15-GHz limits
  77. GRB 990123: BATSE Observations
  78. GRB 990123 Optical Follow-up
  79. GRB981220, Optical Observations
  80. GRB 981220:Optical Observations
  81. GRB 981226 - Infrared Observations
  82. GRB 980326/Host Galaxy
  83. GRB 980923 BATSE Observations
  84. GRB980703, Host galaxy multicolor photometry
  85. GRB 980703: BATSE Observations
  86. GRB 980613: BATSE Observations
  87. SGR1900+14
  88. SGR1900+14
  89. GRB980519 BATSE Observations
  90. BATSE on-board GRB trigger change
  91. GRB980425 BATSE observations
  92. GRB980329
  93. GRB 971214: KPNO Optical Observations
  94. GRB 970228: Keck/LRIS Optical Observations

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