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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"

14803 results found.

  1. GRB990123, is the "radio flare" due to an inhomogeneous medium?
  2. GRB 990123: New Constraints on Possible Foreground Galaxies
  3. GRB990123 Optical Observations
  4. GRB990123, Probability of gravitational lensing
  5. GRB 990123: Detection of the IR Transient, and the Light Curve Fits
  6. GRB 990123: Continued Radio Observations
  7. GRB990123, Preliminary Lens Search Results
  8. On the Lensing Interpretation of GRB 990123
  9. GRB990123, Optical BVRI Observations
  10. GRB990123, OSSE observations
  11. GRB 990123: Strong MeV CGRO-COMPTEL detection now posted on WWW
  12. GRB 990123; Addendum to GCN 223
  13. GRB 990123 Keck Spectrum update
  14. GRB 990123 : Multiple and Distorted Images of the Host Galaxy?
  15. GRB990123 Optical Observations
  16. GRB 990123 Spectroscopic Redshifts
  17. GRB 990123: New Optical Observations, Decay Measure
  18. GRB 990123: Possible Gravitationally Lensed Burst?
  19. GRB 990123: Optical Decay Slope
  20. GRB 990123 r-band photometry
  21. GRB 990123 Optical Follow-up
  22. GRB990123, early optical counterpart detection
  23. GRB 990123: Bright New Source, Possible Optical Transient
  24. Optical Observations of GRB 981220
  25. GRB981220
  26. GRB 981220 Optical observations
  27. GRB 981226 Optical Observations
  28. GRB 980613: Spectroscopy of the host galaxy
  29. GRB 981220 and GRB 981226, optical observations
  30. GRB 981226
  31. GRB 981226 optical observations
  32. GRB981220 B, R and I band observations
  33. Optical Observations of GRB981226
  34. GRB 981226 - Infrared Observations
  35. GRB 981220
  36. GRB 981220, radio observations
  37. GRB 981220: BeppoSAX/GRBM results
  38. GRB981220 I-band Observations
  39. GRB 981220
  40. GRB 981220: RXTE/ASM and BeppoSAX/GRBM results
  41. BeppoSAX NFI Observation of GRB980425
  42. GRB 980923 BATSE Observations
  43. SGR1900+14, BeppoSAX-GRBM observations
  44. GRB980703 Very Long Baseline Interferometry
  45. GRB970508 optical observations
  46. GRB980703, Host galaxy multicolor photometry
  47. GRB980703 - BeppoSAX/GRBM detection
  48. GRB980703 optical photometry
  49. GRB980703 optical observations
  50. GRB980703: Radio transient
  51. GRB980703 H-band Observations
  52. GRB980703 Transient Optical Follow-Up
  53. GRB980703: LOTIS observation at early times
  54. GRB 980703: ASM Position & Intensity
  55. SGR1627-41
  56. GRB 980613 Near-IR observations
  57. GRB980613, optical observations
  58. SGR1627-41, RXTE/ASM observations
  59. GRB 980613: Detection of the probable host galaxy
  60. Reduced error box of SGR 1627-41
  61. SGR1627-41, BeppoSAX-GRBM detections
  62. GRB 980613 Optical Observations
  63. GRB 980613 optical observations
  64. Discovery of a new SGR source, SGR1627-41
  65. GRB980613 observations from Palomar
  66. GRB 980613 new optical/IR observations
  67. SGR 1900+14
  68. BATSE on-board GRB trigger change
  69. GRB 980519 Optical Observations
  70. GRB980519 optical observations
  71. GRB980519 I-band observations
  72. GRB970519, optical follow-up at Schmidt Calern
  73. GRB980519 optical observations
  74. GRB980519 Optical Observations
  75. GRB980519 IPN POSITION
  76. GRB980515, BeppoSAX IAUC to be submitted
  77. BATSE on-board GRB trigger change
  78. GRB 980425 Brightness Temperature
  79. BSAX Observations of GRB980425 field
  80. GRB980425 BATSE observations
  81. GRB980425: optical obs.
  82. GRB980326, optical observations
  83. GRB980329, Fading IR counterpart to radio source
  84. GRB980329 Keck K-band observations
  85. GRB980329 optical observations
  86. GRB980329 near-IR observations
  87. GRB980329 infrared observations
  88. GRB980329 optical observations
  89. GRB980329 near IR observations
  90. GRB980326 optical observations
  91. Optical Observations of GRB 970508
  92. GRB 971214: Redshift from Keck Observations
  93. GRB971227: Plaskett R-band observations
  94. GRB 971227: Optical clarifications
  95. GRB971214: Optical Observations and Calibrations
  96. GRB 971214: Apache Point Observatory Optical Observations
  97. GRB 971214: KPNO Optical Observations
  98. Optical Observations of GRB 971214 at Keck
  99. GRB 971214: Optical Observations
  100. Radio Observations of GRB 971214 at the VLA

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