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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"

17798 results found.

  1. GRB19990123 observations
  2. GRB 990123: BVRI standards in the field
  3. GRB981220, field photometry
  4. GRB990123, Optical observation
  5. GRB990123, Upcoming HST Service Observations
  6. GRB990123, 15-GHz limits
  7. GRB 990123: New Constraints on Possible Foreground Galaxies
  8. GRB990123 Optical Observations
  9. GRB990123, Probability of gravitational lensing
  10. GRB 990123: Detection of the IR Transient, and the Light Curve Fits
  11. GRB990123, Preliminary Lens Search Results
  12. GRB990123, Optical BVRI Observations
  13. GRB 990123: near-infrared observations.
  14. GRB990123, OSSE observations
  15. GRB990123: NIR Observation
  16. "GRB 990123: New BV Observations"
  17. GRB 990123: New Optical Observations, Decay Measure
  18. GRB 990123 Optical Follow-Up
  19. GRB 990123: Possible Gravitationally Lensed Burst?
  20. GRB990123, optical observation
  21. GRB 990123: Pre-Burst Detection of an Apparent Host Galaxy
  22. GRB 990123 r-band photometry
  23. GRB 990123 Optical Follow-up
  24. GRB990123, early optical counterpart detection
  25. GRB990123, BeppoSAX WFC detection and NFI planned follow-up
  26. Optical Observations of GRB 981220
  27. GRB 981226: radio variable
  28. GRB 981226 Optical Observations
  29. GRB981226 BeppoSAX follow up
  30. GRB 981226
  31. GRB 981226 optical observations
  32. GRB 981220:Optical Observations
  33. GRB981226, BeppoSAX Christmas GRB
  34. GRB 981226 optical observations
  35. GRB 981220, radio observations
  36. GRB 981220
  37. GRB 980326/Host Galaxy
  38. BeppoSAX NFI Observation of GRB980425
  39. GRB980329 R,I flux calibration and R,I,K upper limits
  40. GRB980425 Optical Follow-up
  41. GRB970508 optical observations
  42. GRB980519, Optical Observations
  43. GRB980703 optical photometry
  44. GRB980703 optical observations
  45. GRB980703 Transient Optical Follow-Up
  46. GRB980703: LOTIS observation at early times
  47. BeppoSAX NFI observations of GRB 980703
  48. GRB 980703: ASM Position & Intensity
  49. GRB980703 optical followup
  50. Radio observations of SGRs
  51. SGR1900+14 field optical observations
  52. GRB 980613: Optical transient and its host galaxy
  53. GRB 980613: Detection of the probable host galaxy
  54. GRB 980613 Optical Observations
  55. GRB 980613 optical observations
  56. Discovery of a new SGR source, SGR1627-41
  57. GRB980613 Optical Observations
  58. GRB980613 observations from Palomar
  59. GRB980613 BeppoSAX-NFI follow up
  60. GRB980613 Near Infra-Red Observations
  61. GRB971214 Secondary Standards
  62. GRB980519 Secondary Standards
  63. GRB 980519 Optical Observations
  64. GRB 980519
  65. GRB980519 optical observations
  66. GRB 980519 Optical Observations
  67. GRB970519, optical follow-up at Schmidt Calern
  68. GRB980519 Optical Observations
  69. GRB 980519 Optical Observations
  70. GRB980515, BeppoSAX IAUC to be submitted
  71. BSAX Observations of GRB980425 field
  72. SAX J0840.7+2248 Optical Observations
  73. GRB980425: optical obs.
  74. GRB980425: Radio Observations
  75. report on BSAX observations of GRB980425
  76. GRB 980329 ROSAT observation
  77. GRB980326 X-ray Observations
  78. GRB980326, optical observations
  79. GRB980326, optical observations
  80. GRB980329 Keck K-band observations
  81. GRB980326 optical observations
  82. GRB980329 optical observations
  83. GRB980329 VLA observations
  84. GRB980329 optical observations
  85. GRB980326 optical observations
  86. Optical Observations of GRB 970508
  87. Near-IR follow-up on GRB 971227
  88. Optical Observations of the GRB 971227 field
  89. Optical Observations on GRB 971227
  90. GRB971227: Plaskett R-band observations
  91. GRB 971227: Optical clarifications
  92. GRB971227: Further CAHA R-band images
  93. GRB971227: LOTIS observations
  94. GRB971214: Optical Observations and Calibrations
  95. GRB 971214: Optical Observations
  96. Radio Observations of GRB 971214 at the VLA
  97. GRB 971024: KPNO Optical Observations
  98. GRB 970828: Palomar Observations

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