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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"

35272 results found.

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

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