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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"

20484 results found.

  1. GRB981220, field photometry
  2. GRB 990123 NOT Spectrum Update
  3. GRB990123, is the "radio flare" due to an inhomogeneous medium?
  4. GRB 990123: Publicly available reduced HST images
  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. GRB 990123: Continued Radio Observations
  12. GRB990123, Preliminary Lens Search Results
  13. GRB990123, Optical BVRI Observations
  14. GRB 990123: near-infrared observations.
  15. GRB990123, OSSE observations
  16. GRB990123: NIR Observation
  17. "GRB 990123: New BV Observations"
  18. GRB 990123 Optical Follow-Up
  19. GRB 990123; Addendum to GCN 223
  20. GRB 990123: BATSE Observations
  21. GRB990123 Optical Observations
  22. GRB 990123 Spectroscopic Redshifts
  23. GRB 990123: New Optical Observations, Decay Measure
  24. GRB 990123 optical observations
  25. GRB 990123: Pre-Burst Detection of an Apparent Host Galaxy
  26. GRB 990123 radio observations
  27. GRB 990123, new radio source
  28. GRB990123 optical observations
  29. GRB 990123: Optical Decay Slope
  30. GRB 990123, Radio observations
  31. SN 1999E & GRB 980919
  32. Possible identification of SN1999E with GRB980910
  33. Optical Observations of GRB 981220
  34. GRB981220
  35. GRB981220, Correction to GCN 179
  36. GRB981220, Optical Observations
  37. GRB 981220 Optical observations
  38. GRB 981226 Optical Observations
  39. GRB 980613: Spectroscopy of the host galaxy
  40. GRB981226, sub-millimeter observations
  41. GRB981220, sub-millimeter observations
  42. GRB 981220 and GRB 981226, optical observations
  43. GRB981226 Optical Observations
  44. GRB 981226 radio observations
  45. GRB 981226
  46. GRB 981226 optical observations
  47. radio observations of GRB 981226
  48. GRB981220 B, R and I band observations
  49. Optical Observations of GRB981226
  50. GRB 981220:Optical Observations
  51. GRB 981220 optical R and I observations
  52. GRB981226, BeppoSAX Christmas GRB
  53. GRB 981226 - Infrared Observations
  54. GRB 981226 optical observations
  55. GRB 981220
  56. GRB 981220, radio observations
  57. GRB 981220, radio observations
  58. GRB981220 I-band Observations
  59. GRB981220 Optical Observations
  60. GRB 981220
  61. GRB 981220 Optical Observations
  62. GRB 981220, optical observations
  63. GRB 980326/Host Galaxy
  64. GRB980329 R,I flux calibration and R,I,K upper limits
  65. GRB980425 Optical Follow-up
  66. GRB980425: X-ray revised positions
  67. GRB 980923 BATSE Observations
  68. SGR1900+14, BeppoSAX-GRBM observations
  69. GRB980703 Very Long Baseline Interferometry
  70. GRB970508 optical observations
  71. Optical Observations of the Host Galaxy of GRB 980519
  72. GRB980519, Optical Observations
  73. GRB 980703 (NFI observations)
  74. GRB980703 optical photometry
  75. GRB 980703: BATSE Observations
  76. GRB980703 optical observations
  77. GRB980703 H-band Observations
  78. GRB 980703: Spectrum of the proposed optical counterpart
  79. GRB980703: Spectrum of the proposed optical counterpart
  80. GRB980613 Optical Observations
  81. GRB980703 (I band observations)
  82. GRB 980703 H-band Observations
  83. GRB980703 (optical R observations)
  84. GRB980703: radio source/optical transient
  85. BeppoSAX NFI observations of GRB 980703
  86. Radio observations of SGRs
  87. SGR1900+14 field optical observations
  88. GRB 980613 Near-IR observations
  89. GRB980613, optical observations
  90. SGR1627-41, RXTE/ASM observations
  91. GRB 980613: Detection of the probable host galaxy
  92. Reduced error box of SGR 1627-41
  93. GRB 980613: BATSE Observations
  94. GRB 980613 Optical Observations
  95. GRB 980613 optical observations
  96. Discovery of a new SGR source, SGR1627-41
  97. GRB980613 Optical Observations
  98. GRB980613 observations from Palomar
  99. GRB 980613 new optical/IR observations
  100. GRB 980613 optical/IR obs.

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