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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"

20346 results found.

  1. GRB 990506, optical observations
  2. GRB 990506, Optical Observations
  3. GRB 990506 optical observations
  4. GRB 990506, optical observations
  5. GRB 990506, optical observations from +1 to +3 hours
  6. GRB 990506, optical observations
  7. GRB990506 observation plan
  8. IPN localization for GRB990506
  9. GRB 990316 Optical Observations
  10. GRB990316, Optical observations
  11. GRB 990316 optical observations
  12. GRB990316: simultaneous optical observation
  13. ASM/IPN error box for GRB 990308 (BATSE #7457)
  14. GRB990308, Possible new SGR~0209+70
  15. GRB 990123, Field Photometry
  16. GRB 990217 Optical Observations
  17. BATSE Flight Anomaly
  18. GRB990123 observations
  19. GRB990123, Optical Observation
  20. GRB 990123: Discovery of the Probable Host Galaxy
  21. GRB19990123 observations
  22. GRB 990123: BVRI standards in the field
  23. GRB 990123: Updated Keck Spectroscopy Results
  24. GRB981220, field photometry
  25. GRB990123, Optical observation
  26. GRB990123, 15-GHz limits
  27. GRB 990123: New Constraints on Possible Foreground Galaxies
  28. GRB990123 Optical Observations
  29. GRB990123, Probability of gravitational lensing
  30. GRB 990123: Detection of the IR Transient, and the Light Curve Fits
  31. GRB990123, Preliminary Lens Search Results
  32. Search for Potential Images of GRB 990123
  33. GRB990123, Optical BVRI Observations
  34. GRB 990123: near-infrared observations.
  35. GRB990123, OSSE observations
  36. GRB990123: NIR Observation
  37. "GRB 990123: New BV Observations"
  38. GRB 990123: BATSE Observations
  39. GRB 990123: New Optical Observations, Decay Measure
  40. GRB 990123 Optical Follow-Up
  41. GRB 990123: Possible Gravitationally Lensed Burst?
  42. GRB990123, optical observation
  43. GRB 990123 optical observations
  44. GRB 990123: Pre-Burst Detection of an Apparent Host Galaxy
  45. GRB990123 optical observations
  46. GRB 990123 r-band photometry
  47. GRB 990123 Optical Follow-up
  48. GRB990123 Optical Observation
  49. Possible identification of SN1999E with GRB980910
  50. Optical Observations of GRB 981220
  51. GRB 981226: radio variable
  52. GRB 981226 Optical Observations
  53. GRB981226 Optical Observations
  54. GRB981226 BeppoSAX follow up
  55. GRB 981226 radio observations
  56. GRB 981226
  57. GRB 981226 optical observations
  58. radio observations of GRB 981226
  59. GRB981220 B, R and I band observations
  60. GRB 981220:Optical Observations
  61. GRB 981226 optical observations
  62. GRB 981220, radio observations
  63. GRB 981220, radio observations
  64. GRB 981220
  65. GRB 980326/Host Galaxy
  66. GRB981220 IPN error box
  67. BeppoSAX NFI Observation of GRB980425
  68. GRB980329 R,I flux calibration and R,I,K upper limits
  69. GRB980425 Optical Follow-up
  70. GRB 980923 BATSE Observations
  71. GRB980703 Very Long Baseline Interferometry
  72. GRB970508 optical observations
  73. GRB971214, association with a Galactic star?
  74. GRB980519, Optical Observations
  75. GRB980703, Host galaxy multicolor photometry
  76. GRB980703 - BeppoSAX/GRBM detection
  77. GRB 980703 (NFI observations)
  78. GRB980703 optical photometry
  79. GRB980703 optical observations
  80. GRB980703 Transient Optical Follow-Up
  81. GRB980703: LOTIS observation at early times
  82. GRB980613 Optical Observations
  83. GRB980703 (optical R observations)
  84. BeppoSAX NFI observations of GRB 980703
  85. GRB 980703: ASM Position & Intensity
  86. GRB980703 optical followup
  87. Radio observations of SGRs
  88. SGR1900+14 field optical observations
  89. GRB 980613: Optical transient and its host galaxy
  90. SGR1627-41, RXTE/ASM observations
  91. GRB 980613: Detection of the probable host galaxy
  92. GRB 980613 Optical Observations
  93. GRB 980613 optical observations
  94. Discovery of a new SGR source, SGR1627-41
  95. GRB980613 Optical Observations
  96. GRB980613 observations from Palomar
  97. GRB 980613 optical/IR obs.
  98. GRB980613 Near Infra-Red Observations
  99. GRB980613, BeppoSAX WFC positions
  100. GRB971214 Secondary Standards

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