Skip to main content
JSON Notices via Email, Kafka Cron Jobs, Submitter Profile, GCN is Hiring. See news and announcements

GCN Circulars

GCN Circulars are rapid bulletins submitted by and distributed to the community. 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"

6828 results found.

  1. Update of alert from the HAWC Burst Monitor HAWC-200709A
  2. GRB 200709B/HAWC-200907A: Swift-XRT further observations
  3. GRB 200709B: Swift-XRT observations
  4. GRB 200630A: Swift-XRT refined Analysis
  5. GRB 200623A: Swift XRT further observations
  6. GRB 200630A: Fermi GBM detection
  7. GRB 200625A: Fermi-LAT detection is likely a flare from PKS 1127-14
  8. GRB 200623A: Swift-XRT observations
  9. GRB 200623A: Fermi GBM observation
  10. IceCube-200620A: No significant detection in HAWC
  11. Fermi-LAT Gamma-ray Observations of IceCube-200620A
  12. GRB 200613A: R-band observations from HCT
  13. GRB 200619A: Fermi GBM observation
  14. GRB 200613A: SAO RAS optical observations
  15. Swift-XRT observations of IceCube 200615A
  16. IceCube-200615A: No significant detection in HAWC
  17. Fermi-LAT Gamma-ray Observations of IceCube-200615A
  18. IceCube-200614A: No significant detection in HAWC
  19. Fermi-LAT Gamma-ray Observations of IceCube-200614A and detection of a new gamma-ray source, Fermi J0202.8+3132
  20. IceCube-200615A: No counterpart candidates in INTEGRAL SPI-ACS prompt observation
  21. IceCube-200614A: No counterpart candidates in INTEGRAL SPI-ACS prompt observation
  22. GRB 200613A: Swift-XRT afterglow detection
  23. GRB 200613A: Candidate afterglow from OAJ
  24. GRB 200612A: Fermi GBM detection
  25. GRB 200613A: Fermi-LAT detection
  26. GRB 200613A: Fermi GBM observation
  27. GRB 200612A: Swift-XRT refined Analysis
  28. GRB 200530A: Fermi GBM detection
  29. GRB 200530A: Fermi-LAT detection
  30. Fermi-LAT Gamma-ray Observations of IceCube-200530A
  31. IceCube-200530A: No significant detection in HAWC
  32. IceCube-200530A: Candidate Counterparts from the Zwicky Transient Facility
  33. IceCube-200530A: No counterpart candidates in INTEGRAL SPI-ACS prompt observation
  34. GRB 200529A: Swift-XRT refined Analysis
  35. GRB 200529A: Fermi GBM Detection
  36. GRB 200528A: Swift-XRT refined Analysis
  37. GRB 200529A: NOT optical afterglow
  38. GRB 200528A: Fermi GBM Observation
  39. Fermi-LAT Gamma-ray Observations of IceCube-190523A
  40. GRB200521A: ASIM observation
  41. GRB 200524A: Swift-XRT afterglow detection
  42. GRB 200524A: OAJ multicolor afterglow detection
  43. GRB 200524A: Fermi GBM detection
  44. GRB 200524A: 1.3m DFOT Optical Observation of ZTF20abbiixp
  45. GRB 200524A: 3.6m DOT observations of the afterglow candidate ZTF20abbiixp
  46. GRB 200524A: Fermi-LAT detection
  47. GRB 200522A: Swift-XRT refined Analysis
  48. GRB 200517A: Swift-XRT Confirmation of afterglow
  49. GRB 200514B: Fermi GBM observation
  50. GRB 200519A: 1.3m DFOT Optical Afterglow Detection
  51. GRB 200519A: Swift-XRT refined Analysis
  52. GRB 200519A: iTelescope optical afterglow detection
  53. GRB 200517A: Swift-XRT afterglow detection
  54. GRB 200512A: Swift-XRT refined Analysis
  55. Fermi-LAT Gamma-ray Observations of IceCube-200512A
  56. IceCube-200512A: No counterpart candidates in INTEGRAL SPI-ACS prompt observation
  57. GRB 200509A: Swift-XRT refined Analysis
  58. GRB 200424A: Swift-XRT afterglow detection
  59. SGR 1935+2154 the Insight-HXMT observation plan
  60. IceCube-200425A: No significant detection in HAWC
  61. Fermi-LAT Gamma-ray Observations of IceCube-200425A
  62. IceCube-200425A: No counterpart candidates in INTEGRAL SPI-ACS prompt observation
  63. GRB 200424A: Swift/UVOT Upper Limits
  64. GRB 200425A: Swift-XRT refined Analysis
  65. GRB 200424A: Swift-XRT observations
  66. GRB 200415A (possible magnetar Giant Flare in Sculptor Galaxy): INTEGRAL observations
  67. Fermi-LAT Gamma-ray Observations of IceCube-200421A
  68. IceCube-200421A: No significant detection in HAWC
  69. IceCube-200421A: No counterpart candidates in INTEGRAL SPI-ACS and IBIS prompt observation
  70. GRB 200410A: Optical upper limit
  71. GRB 200412B: Swift XRT confirmation of afterglow and UVOT upper limits
  72. GRB 200415A: Fermi-LAT localization update
  73. GRB 200416A: Fermi GBM observation
  74. GRB 200415A: Fermi GBM observation
  75. GRB 200415A: Fermi-LAT detection
  76. GRB 200412B: Xinglong TNT optical observations
  77. GRB 200412B: SAO RAS observations of OT
  78. IceCube-200410A: No significant detection in HAWC
  79. GRB 200405B: Further Swift-XRT observations
  80. GRB 200412B: Swift-XRT afterglow detection
  81. GRB 200412B: Fermi GBM detection
  82. GRB 200412B: Fermi-LAT detection
  83. GRB 200412A: Fermi GBM detection
  84. Fermi-LAT Gamma-ray Observations of IceCube-200410A
  85. GRB 200411A: Fermi GBM observation
  86. GRB 200411A: Swift-XRT refined Analysis
  87. IceCube-200410A: Possible associated excess in INTEGRAL SPI-ACS prompt observation
  88. SGR 1935+2154: Fermi GBM observation
  89. LIGO/Virgo S200225q: Swift XRT observations, 1 X-ray sources
  90. LIGO/Virgo S200224ca: Swift XRT observations, 8 X-ray sources
  91. GRB 200410A: Swift-XRT refined Analysis
  92. GRB 200409A: Swift-XRT refined Analysis
  93. GRB 200405B: Swift-XRT observations
  94. LIGO/Virgo S200316bj: Upper limits from Konus-Wind observations
  95. LIGO/Virgo S200311bg: Upper limits from Konus-Wind observations
  96. LIGO/Virgo S200302c: Upper limits from Konus-Wind observations
  97. LIGO/Virgo S200225q: Upper limits from Konus-Wind observations
  98. LIGO/Virgo S200224ca: Upper limits from Konus-Wind observations
  99. GRB 200325B: Optical upper limit
  100. GRB 200325B: further Swift-XRT observations

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