Target Naming Conventions

Target names are used to provide unique designations for the targets that will be used throughout the proposal. These names will generally also be used in Phase II, and ultimately to designate targets in the HST data archive. Prospective proposers and archival researchers will use these names to determine whether HST has observed a particular object. This facility will be most useful if consistent naming conventions are used.

The following conventions must be followed in naming targets:

A new target name must be defined for each (celestial) target. For example, for several pointings within a galaxy, one might define target names such as NGC4486-NUC, NGC4486-JET, NGC4486-POS1, and NGC4486-POS2.
The maximum allowable length of a target name is 30 characters.
No blanks are permitted in target names. Blanks between a letter and a numeral must be suppressed (e.g., HD140283, NGC4378), but a hyphen (and not an underscore) must replace blanks between two letters or two numerals (e.g., ALPHA-CEN, NGC224-0040+4058 ). Also, a hyphen should be used where required for clarity (e.g., NGC4486-POS1).
Only letters, numerals, hyphens, periods (.), and +or - are allowed in target names; other punctuation is not permitted (e.g., BARNARDS-STAR is valid, but BARNARD'S-STAR is not). Greek letters must be spelled out (e.g., ALPHA-ORI). Letters may be upper-case or lower-case, but will always be treated as if they are upper case (e.g. Alpha-Cen will be treated as if written ALPHA-CEN).
Degree signs must be represented by an upper-case "D" (e.g., CD-42° 14462 becomes CD-42D14462).
Some special target names are reserved for calibrations and other purposes and may not be used for external pointings; see Special Targets.

Catalog Name

The preferred order for catalogs to be used for the designation of various classes of objects is provided below. It is arranged in order of decreasing preference. If a target is not contained in these catalogs, other catalog designations may be used (e.g., 4U X-ray catalog designation, Villanova white-dwarf catalog number, etc.). The use of positional catalogs (SAO, Boss, GC, AGK3, FK4, etc.) is discouraged.

For uncataloged targets, see the section below on Uncataloged Targets.

Stars

Henry Draper Catalog number (e.g., HD140283)is preferred. HDE numbers are discouraged, except in the Magellanic Clouds.
Durchmusterung number (BD, CD, or CPD). In the southern hemisphere, adopt the convention of using CD north of -52 degrees and CPD south of there (e.g., BD+30D3639, CD-42D14462, CPD-65D7691).
General Catalog of Variable Stars designation, if one exists (e.g., RR-LYR, SS-CYG).
AFGL designation.
IRC designation.
IRAS designation.

Star Clusters and Nebulae

New General Catalog (NGC) number (e.g., NGC6397, NGC7027).
Index Catalog (IC) number (e.g., IC418).
For planetary nebulae for which you do not have an NGC or IC designation, the Perek-Kohoutek designation (e.g., PK208+33D1) may be used.
For H II regions for which you do not have an NGC or IC designation, the Sharpless catalog number (e.g., S106) may be used.
For IR nebulae, AFGL designation.

Galaxies and Clusters of Galaxies

NGC number (e.g., NGC4536).
IRAS designation.
IC number (e.g., IC724).
Uppsala Catalog number, only if an NGC or IC number is not available (e.g., UGC11810).
For clusters of galaxies, the Abell catalog number, but only if an NGC or IC number is not available (e.g., ABELL2029).

Quasars and Active Galaxies

The name defined in the compilation by Veron-Cetty and Veron must be used (e.g., 3C273).

Uncataloged Targets

Objects that have not been cataloged or named must be assigned one of the following designations:

Isolated objects must be designated by a code name (the allowed codes are STAR, NEB, GAL, STAR-CLUS, GAL-CLUS , QSO, SKY, FIELD, and OBJ ), followed by a hyphen and the object's J2000 equatorial coordinates, if possible, rounded to seconds of time and seconds of arc (e.g., for a star at J2000 coordinates RA = 1H 34M 28S, DEC = -15D 31' 38", the designation would be STAR-013428-153138).
Uncataloged objects within star clusters, nebulae, or galaxies must be designated by the name of the parent body followed by a hyphen and the rounded J2000 coordinates, if possible, of the object (e.g., for a target within NGC 224 with J2000 coordinates RA = 0H 40M 12S, DEC = +40D 58' 48", the designation would be NGC224-004012+405848).
Positions within nebulae or galaxies may also be designated by the name of the parent object followed by a hyphen and a qualifier. The qualifier should be brief, but informative (e.g., the jet in NGC 4486 could be designated NGC4486-JET). Other examples are: NGC5139-ROA24, LMC-R136A, ABELL30-CENTRAL-STAR, NGC205-NUC.

Special Targets

The names of certain types of targets must be designated by appending a code to the target name. For example, -CALIB should be appended to the name of a target that is being observed only as a calibration standard for other observations. These designations will assist in planning of the observing schedule. The three possible codes are listed in the following table.

Designations of Special Targets

Target Type	Code	Description
External calibration target	-CALIB	An astronomical target used for calibration (e.g., BD+28D4211-CALIB).
Astrometric reference star	-REF	Stars used to determine astrometric positions of other targets (e.g., HD20731-01-REF would designate reference star 01 near HD 20731). Note that the "parallax star"; (the target whose position is being measured) may not have a -REF suffix.
Offset acquisition target	-OFFSET	A target that will be used for an offset acquisition; it is the object that will be acquired first, from which an offset will be applied to move to the target of interest (e.g., 3C273-OFFSET).

Special Calibration Observations

The Observation Summary of a Phase I proposal should include not only all relevant external calibration targets, but also any (non-default) internal calibration targets and calibrations using the Earth. Allowed target names for such observations include: ANTI-SUN, ANY, BIAS, CCDFLAT, DARK, EARTH-CALIB, INTFLAT, KSPOTS, NONE, ORBIT-POLE, UVFLAT, VISFLAT, WAVE. These names may not be used for other external pointings.

Release Documents

The Call for Proposals describes the policies and procedures for submitting a HST Phase I proposal. Get the CP as: PDF [US Letter Size], PDF [A4 Size], or as HTML.

The Primer provides an introductory overview of the Hubble Space Telescope and explains how to calculate the appropriate number of orbits for an observing proposal. Get the Primer as: PDF [US Letter Size], PDF [A4 Size], or as HTML.

Science Justification Templates for Cycle 24 HST Phase I

Full Set of HST Documentation

HST Phase I Roadmap

The Roadmap is a step-by-step guide to proposing and submitting an HST proposal. Download APT here.

DD Time

Up to 10% of the available HST observing time may be reserved for Director's Discretionary (DD) allocation.

Mid-Cycle Proposals

Up to 200 orbits per cycle will be available for Mid-Cycle GO programs. Mid-Cycle programs were initiated in Cycle 23 to provide the community with an opportunity to propose for in-cycle observations of recently-discovered, non-variable objects. As such, they complement Director’s Discretionary programs, which target unexpected transient phenomena and time-critical observations..

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