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"

45653 results found.

  1. GRB050803: CrAO optical observations, possible OT candidate
  2. GRB050803: Optical/UV Upper Limits from Swift-UVOT
  3. GRB 050803: Keck Observations
  4. GRB 050803: Swift-BAT refined analysis
  5. GRB 050802.422: Fading of the afterglow and detection of the host
  6. GRB050803: MASTER further analys
  7. GRB 050803, optical observations
  8. GRB 050803: Magellan Observations
  9. GRB 050803: early Swift XRT analysis results
  10. GRB 050803: TAROT optical limits
  11. GRB050803: MASTER optical observations
  12. GRB050802: Tentative absorption redshift
  13. GRB050803: Swift-BAT detection of a very long burst
  14. GCN GRB observation 050713A
  15. GRB050730: FORS1 and UVES/VLT low- and high-resolution spectroscopy
  16. GRB 050802: Swift/UVOT optical and UV detections
  17. GRB050802: CrAO optical observations
  18. GRB050801: Unchanged decay slope
  19. GRB050802 radio non-detection
  20. GRB 050730: OHP optical observations
  21. GRB 050802: early Swift XRT analysis results
  22. GRB 050802: Swift/UVOT observations
  23. GRB 050802 : Lulin Optical follow-up observation
  24. GRB 050802: Swift-BAT refined analysis
  25. GRB050801: Optical photometry and decay index
  26. GRB 050802: XRT position
  27. GRB 050802: Swift Gamma-ray Burst
  28. GRB050801: Swift/UVOT Optical and UV detections
  29. GRB 050730: Preliminary Analysis of MIKE Spectrum
  30. GCN 050801: early Swift XRT analysis results
  31. GRB 050801: Swift-BAT refined analysis
  32. GRB 050801, SMARTS optical/IR afterglow observations
  33. GRB 050801, afterglow observations
  34. GRB 050730, corrected photometry and break?
  35. GRB 050801: ROTSE-III Early Afterglow Break
  36. GRB050801: Swift-BAT detection of a burst
  37. GRB050801: GCN XRT position is incorrect
  38. GRB 050801: ROTSE-III Detection of Possible Counterpart
  39. GRB 050730: XRT refined analysis
  40. Correction to GCN Circ 3476 on GRB050525A
  41. GRB 050730: early TAROT optical observations
  42. GRB 050726: PROMPT Rc Observations
  43. GRB 050730: RTT150 optical observations
  44. Swift/UVOT photometry of GRB050730
  45. GRB 050730, spectra and optical photometry
  46. GRB050730: Refined BAT analysis of the Swift-BAT burst
  47. GRB 050730: Swift XRT afterglow observations
  48. GRB 050730 XMM-Newton observation
  49. GRB 050730: PROMPT VRcIc Observations
  50. GRB050730, afterglow observations
  51. GRB050730: confirmation of redshift
  52. GRB 050730: Redshift Measurement based on Magellan/MIKE Observations
  53. GRB 050730, SMARTS optical/IR afterglow observations
  54. GRB 050730 : Planned XMM-Newton observation
  55. GRB050730: Liverpool Telescope optical observations
  56. GRB 050730, optical candidate
  57. GRB050730: Swift-BAT detection of a weak burst
  58. GRB 050713A: Swift XRT extended light curve
  59. GRB 050709: PROMPT Rc Observations
  60. GRB050713b: Maidanak optical observations
  61. GRB 050724: Secure Host Redshift from Keck
  62. GRB 050724: WHT optical observations
  63. GRB050726: Swift UVOT observations
  64. GRB 050724: Chandra Observations of the X-ray Afterglow
  65. GRB050724: Refined Radio Position
  66. GRB050713: analysis of the XMM-Newton observation
  67. GRB 050724, SMARTS optical/IR afterglow observations
  68. GRB 050726, SMARTS optical/IR observations
  69. Swift-BAT trigger 147918 is not a real GRB
  70. GRB 050727: RTT150 optical observations
  71. GRB050724: VLT observations of the variable source
  72. GRB050727: KAIT optical limit
  73. GRB050709: Second Epoch Chandra Observation
  74. GRB 050726: PROMPT Rc Observations
  75. GRB050709: Second Epoch Chandra Observation
  76. GRB 050724: dust-scattered X-ray halo detected in SWIFT/XRT observation
  77. GRB050724: Further Radio Observations
  78. GRB 050726: early Swift XRT analysis results
  79. GRB050726: Swift-BAT detection of a weak burst
  80. GRB 050724: Optical Variability in Nearby Galaxy
  81. GRB 050724: J-band observations
  82. GRB 050724: GMOS Imaging and Spectroscopy
  83. GRB 050724: SWIFT XRT refined position
  84. RXTE ASM Detection of GRB050724
  85. GRB050724: Radio Observation
  86. GRB 050724: spectroscopy of object in the XRT error circle
  87. GRB 050724: Optical limit
  88. GRB 050724: optical and near-IR observations
  89. GRB 050724: Optical imaging/astrometry
  90. GRB 050724: RTT150 optical observations
  91. GRB 050724: Swift/UVOT Upper Limit
  92. GRB 050724: early Swift XRT analysis results
  93. GRB 050724 : Lulin early R-band monitoring observations
  94. GRB050724: Refined analysis of the Swift-BAT possible short burst
  95. GRB 050724: possible host galaxy in DSS
  96. GRB050724: a short-burst detected by Swift
  97. Swift-BAT trigger 147325 is not due to a real GRB
  98. GRB050723: XRT distributed coordinates are not related to the burst
  99. GRB 050721: early afterglow light curve
  100. GRB 050721A: Swift-BAT refined analysis

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