Skip to main content
Updates to LVK & CHIME Notices, Schema v7.2.3! See news and announcements

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"

20960 results found.

  1. XRF050509c: Radio Detection
  2. GRB 050416(a): Host Galaxy Redshift Determination
  3. GRB 050607: RTT150 optical observations
  4. GRB050607: refined analysis of prompt REM observations
  5. Swift/UVOT observations of GRB050607
  6. GRB 050607 : Lulin R-band observation
  7. GRB 050607: PROMPT VRcIc Observations
  8. GRB 050607: RAPTOR-S Early Optical Limits
  9. GRB 050525a, Mid-Infrared Observations
  10. GRB 050607: Optical decay and spectral slope
  11. GRB 050607: MDM Observations
  12. GRB 050607 - XRT refined data analysis
  13. Optical Afterglow of GRB 050607
  14. GRB050607: P60 Observations
  15. GRB050607: prompt REM observations
  16. GRB 050603: prediction of t_break
  17. GRB 050603: Redshift
  18. GRB 050603 - XRT data analysis of the first day
  19. GRB 050603: Analysis of UVOT data
  20. GRB050603: Fading Afterglow observed by Swift UVOT
  21. GRB050603, submillimetre observations
  22. GRB 050603: Swift XRT Position
  23. GRB 050603: Swift-BAT refined analysis of a long three-spiked burst
  24. Swift/BAT Detection of GRB050603
  25. GRB 050408: jet break in the XRT light curve
  26. GRB 050525a, infrared observations
  27. GRB 050525a, SMARTS optical/IR afterglow observations
  28. GRB050528, XRT observations
  29. GRB050528: updated Liverpool Telescope limits
  30. Possible GRB050528: no candidate from Liverpool Telescope
  31. GRB050525a: Radio Observations
  32. GRB 050525: RTT150, Optical observations
  33. GRB 050525a: SARA Observations
  34. GRB 050525B: Swift-BAT observations
  35. GRB 050525a: MDM Observations
  36. GRB 050525 : Lulin optical afterglow observations
  37. GRB050525: Super-LOTIS observations
  38. GRB050306: optical afterglow not confirmed
  39. GRB 050525A: BOOTES simultaneous optical observations
  40. GRB050525: Optical observations
  41. GRB 050525: TAROT observations of the early afterglow
  42. GRB 050525, infrared observations
  43. GRB 050525: observatons of the optical afterglow
  44. GRB 050525: Swift Detection of a Bright, Possibly Short Burst
  45. GRB 050525A: ROTSE-III Detection of Possible Counterpart
  46. XRF050522: NIR observations of XRT candidate
  47. XRF 050522: Swift XRT refined analysis
  48. XRF050522: Radio Observations
  49. XRF 050522: Continued NIR P200 Monitoring
  50. RBO Observations of GRB050522
  51. GRB050509b: optical observations
  52. GRB050520: Radio Observations
  53. XRF 050522: Swift XRT observation
  54. XRF050522, BVRcIc field photometry
  55. XRF 050522 : Lulin observations
  56. XRF050522: Optical Observations
  57. XRF050522: Near-infrared Observations
  58. XRF 050522: KAIT observations
  59. GRB 050520: VLT/ULTRACAM observations
  60. Swift UVOT Observations of GRB 050520
  61. XRF 050509c: Swift XRT Upper Limit
  62. XRF050509c: Radio Observations
  63. RBO Observations of GRB050520
  64. GRB 050520: P200 Observations
  65. RBO Observations of GRB050520
  66. GRB 050520: TAROT optical limit
  67. GRB 050520: Swift XRT position
  68. GRB 050520: VLT/ULTRACAM observations
  69. GRB 050520: OSN optical observations
  70. GRB 050504: Swift XRT afterglow candidate has faded
  71. XRF 050509c optical afterglow
  72. GRB 050509B: Subaru Optical Observations
  73. GRB050509b, SDSS pre-burst observations
  74. GRB 050509b: Keck/Chandra Cross-Correlation
  75. Chandra observation of GRB 050509b
  76. GRB050509B: Optical/Infared observations
  77. GRB 050509b Milagro GeV/TeV Observations
  78. GRB050509B: Optical observations at the Very Large Telescope
  79. GRB 050509b: No Optical Variability in XRT Error Circle
  80. GRB 050509B: WSRT Radio Observations
  81. GRB050509c: REM NIR and Optical observations (errata corrige to GCN 3400)
  82. GRB 050505, early TAROT observation
  83. GRB050509c: REM NIR and Optical observations
  84. GRB 050505: SARA Observations
  85. Swift UVOT Follow-up Observations of GRB 050509B
  86. GRB 050509B, Optical Observations
  87. GRB050509a: Swift UVOT observations
  88. GRB 050509b: Optical observations
  89. GRB 050509b: Possible Optical Counterpart
  90. GRB 050509A: Optical observations
  91. GRB 050509b: Optical Counterpart Candidate
  92. GRB050509b: Radio Observations
  93. GRB 050509b: PAIRITEL and WIYN Observations
  94. GRB 050509b: optical observations
  95. GRB 050509b: Swift XRT Position
  96. Swift Detection of GRB050509b: A short duration burst
  97. Swift Detection of the Burst GRB050509
  98. GRB 050505: early time observations
  99. GRB 050505 - Faulkes Telescope North observations
  100. GRB 050502a: Swift XRT Upper Limit

Advanced

Download all Circulars as a .tar.gz archive (updated once a day):
Questions or comments?
Contact GCN directly.
Have you found a bug in GCN?
Open an issue.
Want to contribute code to GCN?
Get involved on GitHub.

gcn.nasa.gov

A service of the Astrophysics Science Division at NASA Goddard Space Flight Center

Looking for U.S. government information and services? Visit USA.gov