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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"

28275 results found.

  1. EP240804a: GSP detects optical candidate counterpart
  2. GRB 240805B: Swift detection of a burst
  3. GRB 240805A: INTEGRAL spectral analysis
  4. EP240801a: Continued optical observations at ZTSh (CraO)
  5. EP240804a: LCOGT optical counterpart detection
  6. EP240804a: NOT optical counterpart detection
  7. EP240804a: EP-WXT detection and EP-FXT follow-up observation of a fast X-ray transient
  8. EP240802a: Montarrenti Observatory optical upper limit
  9. EP240801a: Osservatorio Astronomico Nastro Verde upper limit
  10. EP240802A: Bassano Bresciano Observatory upper limit
  11. GRB 240802A: SVOM/GRM observation
  12. EP240802a: Time coincidence with GRB 240802A and optical upper limits with Kinder observations
  13. Fermi trigger No 744278264: Global MASTER-Net observations report
  14. EP240802a: EP-WXT detection and EP-FXT follow-up observation of a fast X-ray transient
  15. GRB 240802A: AstroSat CZTI detection of a long burst
  16. EP240801a: further SAO RAS optical observations
  17. EP240801a: optical observations at CrAO and AbAO
  18. EP240801a: Leavitt Observatory optical observations
  19. EP240801a: SAO RAS optical observations
  20. EP240801a: JinShan optical observations
  21. GRB 240727C: SVOM/GRM observation
  22. EP240801a: follow-up observation with LCOGT
  23. Fermi GBM trigger 744179961 / 240801194 can not be confirmed as a GRB
  24. GRB 240730A: Swift-BAT refined analysis
  25. EP240801a: GSP follow-up observations of the candidate counterpart
  26. EP240801a: Kinder follow-up observations of the candidate counterpart
  27. EP240801a: GMG observation
  28. EP240801a: TRT optical counterpart detection
  29. EP240801a: EP-WXT detection and EP-FXT follow-up observation of a fast X-ray transient
  30. GRB 240801B: AstroSat CZTI detection of a bright long burst
  31. GRB 240801A: Fermi GBM Final Real-time Localization
  32. GRB 240730C: AstroSat CZTI detection of a long burst
  33. GRB 240730A: Osservatorio Astronomico Nastro Verde upper limit
  34. GRB240730A: BOOTES-5/JGT early optical upper limit
  35. Swift GRB 240730A: Global MASTER-Net observations report
  36. GRB 240730A: Swift-XRT refined Analysis
  37. GRB 240715A: Swift-XRT afterglow detection
  38. GRB 240730A: Swift/UVOT Upper Limits
  39. GRB 240730A: Enhanced Swift-XRT position
  40. GRB 240730A: Swift detection of a burst
  41. GRB 240727A: Swift-BAT refined analysis
  42. LIGO/Virgo/KAGRA S240615dg: GRAWITA wide-field optical observations
  43. GRB 240727A: observations of optical counterpart.
  44. GRB 240727B: Swift-XRT observations
  45. Fermi GRB 240727A: Global MASTER-Net observations report
  46. GRB 240727A: Swift/UVOT detection
  47. GRB 240727A: Osservatorio Astronomico Nastro Verde upper limit
  48. GRB 240727A: NOT optical observation
  49. GRB 240727A: JinShan optical upper limits
  50. GRB 240727A Bassano Bresciano Observatory upper limit
  51. GRB 240727C: AstroSat CZTI detection of a long burst
  52. GRB 240727A: Swift-XRT refined Analysis
  53. Fermi GRB 240726A: Global MASTER-Net observations report
  54. GRB 240727A: Enhanced Swift-XRT position
  55. GRB 240727B: Fermi GBM Observation
  56. GRB240529A: VIRT optical transient detection
  57. GRB 240727B: Swift/BAT-GUANO arcminute localization of a long burst
  58. GRB 240726A: SVOM/GRM observation
  59. GRB 240726B: AstroSat CZTI detection of a short burst
  60. GRB240727A: Skynet Optical Afterglow Observations
  61. GRB 240727A: TRT optical afterglow detection
  62. GRB 240727A: Swift detection of a burst
  63. IceCube-240725A: Upper limits from a search for additional neutrino events in IceCube
  64. Fermi-LAT gamma-ray observations of IceCube-240725A
  65. Swift Trigger 1244778 is not a GRB
  66. IceCube-240721A: Two candidates from the Zwicky Transient Facility
  67. GRB 240720A: Swift-BAT refined analysis
  68. IceCube-240721A: Upper limits from a search for additional neutrino events in IceCube
  69. LIGO/Virgo/KAGRA S240716b: Upper limits from Swift/BAT-GUANO
  70. LIGO/Virgo/KAGRA S240703ad: Upper limits from Swift/BAT-GUANO
  71. Fermi-LAT gamma-ray observations of IceCube-240721A
  72. GRB 240720B: SVOM/GRM observation
  73. GRB 240720B: AstroSat CZTI detection of a short burst
  74. GRB 240718A: Fermi GBM Observation
  75. GRB 240718A: SVOM/GRM observation
  76. GRB 240718A: BALROG localization (Fermi Trigger 742976945 / GRB 240718270)
  77. GRB 240712A: Swift-BAT refined analysis
  78. GRB 240716A: GECAM-B detection of a long burst
  79. IceCube-Cascade 240714A: X-ray follow-up observation with EP-FXT
  80. Fermi-LAT gamma-ray observations of IceCube-cascade-240714A
  81. GRB 240715A: Swift/UVOT observations of the XRT sources.
  82. GRB 240715A: Swift-XRT observations
  83. GRB240713A: Swift/UVOT Upper LImits
  84. EP240708a: X-ray follow-up observations with Swift/XRT
  85. LIGO/Virgo/KAGRA S240716b: Updated Sky localization
  86. GRB 240713A: Swift-XRT observations
  87. GRB 240715A: TRT optical upper limit on one Swift/XRT candidate
  88. GRB 240712A: Swift-XRT refined Analysis
  89. GRB 240713A: LAST optical upper limit
  90. LIGO/Virgo/KAGRA S240716b: Identification of a GW compact binary merger candidate
  91. Fermi GRB 240715A: Global MASTER-Net observations report
  92. GRB 240713A: optical upper limits from the INAF Asiago Observatory
  93. GRB240715A: GRANDMA Optical Upper Limits
  94. GW s240422ed: Swift UVOT follow-up
  95. GRB 240712A: Swift/UVOT Upper Limits
  96. JinShan confirmation of the EP-WXT source triggered on July 14th due to a flaring star
  97. The EP-WXT source triggered on July 14th is likely a flaring star
  98. GRB 240713A: J-band upper limit from WINTER
  99. GRB 240713A: NOT optical upper limits on three EP/FXT candidates
  100. GRB 240713A: JinShan optical upper limits

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