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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"

27549 results found.

  1. The Likely Optical/Infrared Afterglow of GRB 001011
  2. HETE positions added to GCN
  3. GRB000926 - Amateur Optical Observations
  4. GRB001007: Optical observations
  5. CONCAM null result on GRB001005
  6. GRB 000926 Chandra Observation
  7. Public availability of BeppoSAX data of GRB000926
  8. GRB000926: X-ray afterglow by BeppoSAX: revised fluxes (fwd)
  9. GRB000926: X-ray afterglow by BeppoSAX. Refined analysis
  10. GRB000926 : increasing optical decay slope
  11. GRB 000926: Lightcurve Update and Predictions
  12. GRB 000926, optical observation by Oksanen (vsnet-grb)
  13. GRB000926: X-ray afterglow by BeppoSAX & plan of BSAX & Chandra obs.
  14. CONCAM crude optical limits before and after GRB000926
  15. GRB 000926: Preliminary R-band Lightcurve
  16. GRB 000926 HST/Chandra TOO Status
  17. Spectroscopic Redshift of GRB 000926
  18. GRB000911: Optical observations
  19. GRB000830, BVRI field photometry
  20. GRB000830: Optical observations
  21. "Snapshot" afterglow IDs and GRB 000830
  22. GRB000830: Optical observations
  23. HST/STIS observations of the chaotic environment of GRB 980613
  24. GRB000812, Radio observations
  25. GRB 991208 Host Galaxy Imaging
  26. GRB 990510: Possible detection of a host galaxy
  27. GRB 991216, HST/STIS observations
  28. GRB000620, Radio Observations
  29. GRB981226, HST/STIS observations of the host galaxy
  30. GRB000630, optical observations
  31. GRB 000630: Detection of the Optical Afterglow
  32. GRB000630, BVRI Field Photometry
  33. GRB 990506, HST/STIS Observations of the Host Galaxy
  34. GRB990308, HST/STIS observations of the host galaxy
  35. GRB000620: BeppoSAX WFC and GRBM detection
  36. GRB990123, HST/STIS observations of the host galaxy
  37. GRB000615, further R-band photometry
  38. GRB000615, R-band photometry
  39. GRB980425, HST/STIS observations of the host galaxy
  40. GRB000528: follow-up X-ray measurements and update of IPN annulus
  41. Optical Follow-up of GRB000529 Error Box
  42. GRB000604 optical non-detection
  43. GRB000604, optical observations
  44. GRB 000418: Detection of the Host Galaxy
  45. X-ray Afterglow of GRB 000529
  46. GRB000519, BVRI field photometry
  47. GRB 000418, Optical observation
  48. GRB000508B, BVR field photometry
  49. Possible GRB-related phenomenon
  50. GRB000424, UBVRI field photometry
  51. GRB000424, optical observations
  52. GRB 000429, UBVRI field photometry
  53. GRB000418, Radio detection
  54. GRB000418, K'-band photometry
  55. GRB 000418, Optical Observation
  56. GRB 000418, optical observation
  57. GRB 000418, Optical Observation
  58. GRB000424, optical observations
  59. RE: Budget cuts in BeppoSAX operations: impact on GRB observation
  60. X-ray burst or X-ray rich GRB 000416 observed by BeppoSAX
  61. Budget cuts in BeppoSAX operations: impact on GRB observations
  62. GRB000408: Optical CCD Observations from MIRO
  63. GRB000326 Optical Observations
  64. GRB 000313 - optical transient in the BATSE error box
  65. GRB 000301C: A Precise Redshift Determination
  66. GRB 000301C: HST/STIS CCD Imaging of the field
  67. GRB 000301C: K' Observations
  68. GRB000301C - Host galaxy not detected in R (?)
  69. GRB 000301c near-IR observations
  70. GRB 000301C, Optical Color
  71. GRB000301C 250 GHz detection
  72. GRB000301C, near-infrared observations (JHK' photometry)
  73. GRB000301C, optical observations
  74. GRB000301c, near-infrared observations
  75. GRB 000214 near-IR observations
  76. GRB 000214 ``Valentine's Day Burst'': BeppoSAX NFI Observation
  77. GRB000210, Radio Observations
  78. Correction to GCN 557 (GRB000214: BeppoSAX GRBM and WFC Detection)
  79. GRB000214: BeppoSAX GRBM and WFC Detection
  80. GRB000210 X-ray afterglow
  81. GRB000214: X-ray afterglow candidate
  82. Correction to Chandra Position of GRB000210 afterglow
  83. Optical observations of the Chandra X-ray source for GRB000210
  84. Chandra Observations of GRB000210 X-ray Afterglow
  85. GRB000210: possible afterglow detection with BeppoSAX NFI
  86. GRB000210: BeppoSAX GRBM and WFC Detection
  87. GRB 000131 Optical Observations
  88. GRB 991208, radio observations
  89. GRB000126, optical observations
  90. GRB 000115 Optical observations
  91. BATSE Observations of GRB000115
  92. Second RXTE Observation of GRB 000115
  93. GRB991216 late optical observation
  94. GRB 991216 VLBA Observations
  95. GRB 991216: J band spectrophotometry
  96. GRB 991216: Detection of the Host and/or Absorber Galaxy
  97. GRB 991216 RXTE ASM Observations
  98. Chandra observation of the X-ray afterglow of GRB991216
  99. GRB 991216 Optical spectroscopy/imaging
  100. GRB991216 Optical and IR observations

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