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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"

14824 results found.

  1. WSRT 4.8 GHz observations of GRB001109
  2. IPN TRIANGULATION OF GRB001025B (SHORT/HARD)
  3. GRB001007: Optical observations
  4. GRB000926 - Amateur Optical Observations
  5. CONCAM null result on GRB001005
  6. CONCAM crude optical limits before and after GRB000926
  7. GRB 990510: Possible detection of a host galaxy
  8. GRB 000630: Detection of the Optical Afterglow
  9. GRB000620: BeppoSAX WFC and GRBM detection
  10. GRB000615, R-band photometry
  11. GRB980425, HST/STIS observations of the host galaxy
  12. GRB000604 optical non-detection
  13. GRB000604, optical observations
  14. GRB 000418: Detection of the Host Galaxy
  15. X-ray Afterglow of GRB 000529
  16. Possible GRB-related phenomenon
  17. GRB000424, optical observations
  18. GRB000418, Radio detection
  19. GRB000418, K'-band photometry
  20. GRB 000418, Optical Observation
  21. GRB000424, optical observations
  22. RE: Budget cuts in BeppoSAX operations: impact on GRB observation
  23. X-ray burst or X-ray rich GRB 000416 observed by BeppoSAX
  24. GRB 000301C: A Precise Redshift Determination
  25. GRB 000301C: HST/STIS CCD Imaging of the field
  26. GRB000301C - Host galaxy not detected in R (?)
  27. GRB000301C 250 GHz detection
  28. Correction to GCN 557 (GRB000214: BeppoSAX GRBM and WFC Detection)
  29. GRB000214: BeppoSAX GRBM and WFC Detection
  30. Optical observations of the Chandra X-ray source for GRB000210
  31. GRB000210: possible afterglow detection with BeppoSAX NFI
  32. GRB000210: BeppoSAX GRBM and WFC Detection
  33. GRB 000131 Optical Observations
  34. GRB000126, optical observations
  35. Second RXTE Observation of GRB 000115
  36. GRB 991216 VLBA Observations
  37. GRB 991216: Detection of the Host and/or Absorber Galaxy
  38. GRB 991216 RXTE ASM Observations
  39. GRB 991216 Optical spectroscopy/imaging
  40. GRB 991208 Infrared Detection
  41. GRB 991216--Summary of RXTE Observations
  42. GRB991216 Optical Observations
  43. GRB991208 - millimeter detection
  44. GRB 991208 - OVRO detection
  45. GRB 991208 optical observations
  46. GRB991106: BeppoSAX/BATSE results
  47. GRB 991106, optical observations
  48. GRB991106: the first BeppoSAX short GRB detection?
  49. GRB991105: SAX-GRBM/-WFC detection
  50. GRB 990915 optical observations
  51. GRB990908, another BeppoSAX-GRBM/WFC burst detection
  52. GRB 990806 Optical observations
  53. BeppoSAX NFI Observation of GRB990705
  54. BeppoSAX NFI Observation of GRB990705
  55. Updated Astrometry for the IR Counterpart of GRB990705
  56. Infrared and Optical Observations of GRB990705
  57. GRB990704, optical observations
  58. GRB990704: BeppoSAX detection
  59. GRB 990506 - clarification to GCN 352
  60. GRB 990506 Radio Transient
  61. X-ray/GRB 1SAX J0835.9+5118, Optical Observations
  62. X-ray/GRB 1SAX J0835.9+5118, Optical Observation
  63. radio detection of X-ray/GRB transient
  64. GRB 990506 R band observations
  65. GRB 990506: BATSE Observations
  66. GRB 990506, optical observations
  67. GRB 990506, optical observations from +1 to +3 hours
  68. GRB990321 IPN TRIANGULATION
  69. GRB 990316 Optical Observations
  70. ASM/IPN error box for GRB 990308 (BATSE #7457)
  71. GRB 990123: Discovery of the Probable Host Galaxy
  72. GRB19990123 observations
  73. GRB 990123 NOT Spectrum Update
  74. GRB990123, 15-GHz limits
  75. GRB 990123: New Constraints on Possible Foreground Galaxies
  76. GRB990123 Optical Observations
  77. GRB990123, Probability of gravitational lensing
  78. GRB 990123: Detection of the IR Transient, and the Light Curve Fits
  79. GRB 990123: Continued Radio Observations
  80. GRB 990123: Strong MeV CGRO-COMPTEL detection now posted on WWW
  81. GRB 990123 Optical Follow-Up
  82. GRB 990123; Addendum to GCN 223
  83. GRB 990123 : Multiple and Distorted Images of the Host Galaxy?
  84. GRB 990123 Optical Follow-Up
  85. GRB 990123: Possible Gravitationally Lensed Burst?
  86. GRB 990123: Pre-Burst Detection of an Apparent Host Galaxy
  87. GRB 990123 radio observations
  88. GRB990123, early optical counterpart detection
  89. GRB990123, BeppoSAX-NFI X-ray afterglow detection
  90. GRB990123, BeppoSAX WFC detection and NFI planned follow-up
  91. GRB981220
  92. GRB 981220 Optical observations
  93. GRB 981226 Optical Observations
  94. GRB 981226
  95. GRB 981226 optical observations
  96. GRB981220 B, R and I band observations
  97. Optical Observations of GRB981226
  98. GRB 981220
  99. GRB 980326/Host Galaxy
  100. GRB 980923 BATSE Observations

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