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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"

25905 results found.

  1. GRB 010921: The afterglow of HETE #1761
  2. GRB010921, negative optical observations
  3. GRB010921 field photometry
  4. GRB 010222 - WHT BVRI images
  5. GRB 010629 Optical Observations
  6. GRB 010222 /corrections to VBT data
  7. GRB010412, field photometry
  8. GRB 980326: Late-time HST/STIS observations
  9. Further Optical Observations of GRB 010324
  10. GRB010222, late-time optical observation
  11. Congratulate Scott on the 1000th GRB Coordinates Network Circular!
  12. GRB010222: Chandra X-ray Observatory Observation
  13. GRB 010222, Optical Observations
  14. GRB 010214, I-band data
  15. Sub-millimeter Excess/GRB 010222
  16. GRB 010222 HST/Chandra TOO
  17. GRB010222: R-band data
  18. GRB010222, possible increase of optical decay slope
  19. GRB010222: fading behavior
  20. GRB 010220: Near-IR Observations
  21. GRB010214 follow-up from Hanle
  22. GRB010222: Another absorption line system
  23. GRB010222: Optical decay slope
  24. GRB010222: R-band fading behavior
  25. GRB010222: possible optical counterpart
  26. GRB010214, candidate optical afterglow
  27. GRB 010214: X-Ray afterglow
  28. GRB010213, Radio Observations
  29. J-Band Observation of GRB 010214.
  30. GRB010214 Optical Observation
  31. GRB010214: BeppoSAX/NFI Observations
  32. GRB 010214, optical observations
  33. Optical observations of GRB 001018 with JCAM
  34. GRB 001212 Optical Observation
  35. GRB001120: Gunn-i observations
  36. Optical/NIR observations of GRB001109
  37. GRB 001109: deep JHK upper limits
  38. GRB 001109 X-ray afterglow with BeppoSAX
  39. GRB001007: Optical observations
  40. GRB001007, Radio observations
  41. GRB 001018, Possible Radio Afterglow
  42. GRB 000926: Improved Absorber Redshift
  43. The Likely Optical/Infrared Afterglow of GRB 001011
  44. HETE positions added to GCN
  45. GRB001007: Optical observations
  46. GRB 000926 Chandra Observation
  47. Public availability of BeppoSAX data of GRB000926
  48. GRB000926: X-ray afterglow by BeppoSAX: revised fluxes (fwd)
  49. GRB000926: X-ray afterglow by BeppoSAX. Refined analysis
  50. GRB000926 : increasing optical decay slope
  51. GRB 000926: Lightcurve Update and Predictions
  52. GRB 000926, optical observation by Oksanen (vsnet-grb)
  53. GRB000926: X-ray afterglow by BeppoSAX & plan of BSAX & Chandra obs.
  54. GRB 000926: Preliminary R-band Lightcurve
  55. GRB 000926 HST/Chandra TOO Status
  56. Spectroscopic Redshift of GRB 000926
  57. GRB000911: Optical observations
  58. GRB000830, BVRI field photometry
  59. GRB000830: Optical observations
  60. "Snapshot" afterglow IDs and GRB 000830
  61. GRB000830: Optical observations
  62. HST/STIS observations of the chaotic environment of GRB 980613
  63. GRB000812, Radio observations
  64. GRB 991208 Host Galaxy Imaging
  65. GRB 991216, HST/STIS observations
  66. GRB000620, Radio Observations
  67. GRB981226, HST/STIS observations of the host galaxy
  68. GRB000630, optical observations
  69. GRB 000630: Detection of the Optical Afterglow
  70. GRB000630, BVRI Field Photometry
  71. GRB 990506, HST/STIS Observations of the Host Galaxy
  72. GRB990308, HST/STIS observations of the host galaxy
  73. GRB990123, HST/STIS observations of the host galaxy
  74. GRB000615, further R-band photometry
  75. GRB000528: follow-up X-ray measurements and update of IPN annulus
  76. Optical Follow-up of GRB000529 Error Box
  77. X-ray Afterglow of GRB 000529
  78. GRB000519, BVRI field photometry
  79. GRB 000418, Optical observation
  80. GRB000508B, BVR field photometry
  81. Possible GRB-related phenomenon
  82. GRB000424, UBVRI field photometry
  83. GRB 000429, UBVRI field photometry
  84. GRB000418, K'-band photometry
  85. GRB 000418, Optical Observation
  86. GRB 000418, optical observation
  87. GRB 000418, Optical Observation
  88. RE: Budget cuts in BeppoSAX operations: impact on GRB observation
  89. Budget cuts in BeppoSAX operations: impact on GRB observations
  90. GRB000408: Optical CCD Observations from MIRO
  91. GRB000326 Optical Observations
  92. GRB 000313 - optical transient in the BATSE error box
  93. GRB 000301C: K' Observations
  94. GRB 000301c near-IR observations
  95. GRB 000301C, Optical Color
  96. GRB000301C 250 GHz detection
  97. GRB000301C, near-infrared observations (JHK' photometry)
  98. GRB000301C, optical observations
  99. GRB000301c, near-infrared observations
  100. GRB 000214 near-IR observations

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