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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"

35277 results found.

  1. optical observation of the X-ray/GRB transient SAX J0835.9+5118
  2. Optical report on X-ray/GRB transient
  3. radio detection of X-ray/GRB transient
  4. BeppoSAX: A new fast X-ray transient
  5. GRB 990510: optical observations
  6. GRB990510: photometric and spectroscopic observations with the VLT
  7. GRB 990510: optical linear polarization
  8. GRB 990510: optical observations
  9. GRB990510, VI observations
  10. GRB 990506 R band observations
  11. GRB990510: X-ray afterglow
  12. GRB 990510: optical observation
  13. VLT spectrum of GRB990510
  14. GRB 990510: Broad Band Break
  15. GRB 990510: BATSE Observations
  16. GRB 990510 Optical Observations
  17. GRB 990510, BVI photometry
  18. GRB 990510 optical observations
  19. GRB 990510: BeppoSAX/GRBM observations
  20. GRB990510 optical observations
  21. GRB 990510 optical observations
  22. GRB 990510 optical observations
  23. Galactic extinction towards GRB 990510
  24. GRB 990510 optical observations
  25. IPN localization of GRB990510
  26. GRB 990506 Radio Observations
  27. GRB 990123, optical monitoring
  28. GRB 990506: BATSE Observations
  29. GRB 990506, optical observations
  30. GRB 990510: Final BeppoSAX-WFC Coordinates
  31. GRB 990506, Optical Observations
  32. GRB 990506 optical observations
  33. GRB 990506 optical observations
  34. GRB 990506, optical observations
  35. GRB990506 observation plan
  36. Refined IPN error box for GRB990506
  37. GRB 990506: Limits on the possible optical transient
  38. GRB 990506, armchair astronomy
  39. GRB 990506, optical observations from +1 to +3 hours
  40. GRB 990506, optical observations
  41. GRB990506 observation plan
  42. New IPN/RXTE error box for GRB990506
  43. IPN localization for GRB990506
  44. GRB 970228: Redshift and properties of the host galaxy
  45. IPN localization of GRB990427
  46. GRB981220 VLBA observations
  47. GRB990321 REFINED IPN ANNULUS
  48. GRB990323 PRECISE IPN POSITION
  49. GRB990321 IPN TRIANGULATION
  50. GRB 990316 Optical Observations
  51. GRB 990316, Radio observations
  52. GRB 990316, Optical observations
  53. GRB990316, Optical observations
  54. GRB 990316 optical observations
  55. GRB990316: simultaneous optical observation
  56. ASM/IPN error box for GRB 990308 (BATSE #7457)
  57. GRB990308 not a new SGR
  58. GRB 990308a and GRB 990308b
  59. GRB990308 (Trig. 7457), optical observations
  60. GRB981220, IPN localization
  61. GRB 981220, radio observations
  62. GRB 990123, Field Photometry
  63. GRB 990217 Optical Observations
  64. GRB 990217, radio observations
  65. Optical Observations of GRB990217
  66. GRB990123: Caltech STIS Photometry and Images
  67. GRB990123 observations
  68. GRB990123, Optical Observation
  69. GRB 990123: Discovery of the Probable Host Galaxy
  70. GRB 990123: Reduced HST Images
  71. For Immediate Posting to GCN - HST Data GRB 990123 Available
  72. GRB19990123 observations
  73. GRB 990123: BVRI standards in the field
  74. GRB 990123: Updated Keck Spectroscopy Results
  75. GRB981220, field photometry
  76. GRB 990123 NOT Spectrum Update
  77. GRB990123, Optical observation
  78. GRB990123, is the "radio flare" due to an inhomogeneous medium?
  79. GRB 990123: Publicly available reduced HST images
  80. GRB990123, Upcoming HST Service Observations
  81. GRB 990123: New Constraints on Possible Foreground Galaxies
  82. GRB990123 Optical Observations
  83. GRB990123, Probability of gravitational lensing
  84. GRB 990123: Detection of the IR Transient, and the Light Curve Fits
  85. GRB 990123: Continued Radio Observations
  86. GRB990123, Preliminary Lens Search Results
  87. GRB 990123: Correction to GCN 230 - C.A. Young added to author list
  88. On the Lensing Interpretation of GRB 990123
  89. Search for Potential Images of GRB 990123
  90. Search for Potential Images of GRB 990123
  91. GRB990123, Optical BVRI Observations
  92. GRB 990123: near-infrared observations.
  93. GRB990123, OSSE observations
  94. GRB 990123: Strong MeV CGRO-COMPTEL detection now posted on WWW
  95. "GRB 990123: New BV Observations"
  96. GRB 990123 Optical Follow-Up
  97. GRB 990123; Addendum to GCN 223
  98. GRB 990123: BATSE Observations
  99. GRB 990123 Keck Spectrum update
  100. GRB 990123 : Multiple and Distorted Images of the Host Galaxy?

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